Carrier 48HC 04-28, 50HC 04-28 Controls, Start-up, Operation And Troubleshooting

Download

48/50HC 04-28

Single Package Rooftop Units

with ComfortLink Controls Version 3.X and Puron

(R-410A) Refrigerant

Controls, Start-Up, Operation and

Troubleshooting

PAGE

SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . 3

GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

BASIC CONTROL USAGE . . . . . . . . . . . . . . . . . . . . . 4

ComfortLink Control . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Scrolling Marquee . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Accessory Navigator™ Display . . . . . . . . . . . . . . . . . 4

Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

System Pilot™ and Touch Pilot™ Devices . . . . . . . . 6

CCN Tables and Display . . . . . . . . . . . . . . . . . . . . . . . 6

Force Hierarchy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Generic Status Display Table . . . . . . . . . . . . . . . . . . . 6

Conventions Used in This Manual . . . . . . . . . . . . . . . 7

START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Unit Preparation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Compressor Mounting . . . . . . . . . . . . . . . . . . . . . . . . 7

Refrigerant Service Ports . . . . . . . . . . . . . . . . . . . . . . 7

Crankcase Heater(s) . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Compressor Rotation . . . . . . . . . . . . . . . . . . . . . . . . . 7

Power Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Internal Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Evaporator Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

• 48/50HC 04-06 UNITS WITH DIRECT DRIVE FANS

• BELT DRIVE UNITS

• BELT DRIVE UNITS WITH A VFD

Condenser Fans and Motors . . . . . . . . . . . . . . . . . . . 8

Return-Air Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Outdoor-Air Inlet Screens . . . . . . . . . . . . . . . . . . . . . 8

Accessory Installation . . . . . . . . . . . . . . . . . . . . . . . . 8

Orifice Change (48HC) . . . . . . . . . . . . . . . . . . . . . . . . 8

Gas Heat (48HC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Units with EnergyX® System . . . . . . . . . . . . . . . . . . 10

• BASE UNIT EVAPORATOR FAN

• START-UP CHECK LIST

•ERV TEST MODE

• ERV CONFIGURATION

• ERV WITH ECONOMIZER ADDITIONAL CONFIGURATIONS

• ADJUSTING ERV OPTIONS

CONTROLS QUICK SET-UP . . . . . . . . . . . . . . . . . . . 11

Control Set Point and Configuration Log . . . . . . . . 11

Thermostat Control . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Space Temperature Sensor Control - Direct

Wired (T-55 or T-56 or T-59) . . . . . . . . . . . . . . . . . 11

T-58 Communicating Room Sensor . . . . . . . . . . . . 12

CCN Linkage Control . . . . . . . . . . . . . . . . . . . . . . . . 12

System Pilot™ - Communication Space Sensor . . 12

Thermidistat Control . . . . . . . . . . . . . . . . . . . . . . . . . 12

Space Humidistat Control . . . . . . . . . . . . . . . . . . . . . 12

Relative Humidity Sensor Control . . . . . . . . . . . . . .12

CCN Communication . . . . . . . . . . . . . . . . . . . . . . . . .12

Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

• ECONOMIZER

• POWER EXHAUST

• ELECTRIC HEAT

• FIRE SHUTDOWN

• OUTDOOR ENTHALPY

•IAQ SWITCH

• IAQ SENSOR

• OAQ SENSOR

• FAN STATUS

• FILTER STATUS

Programming Operating Schedules . . . . . . . . . . . . . 13

SERVICE TEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Independent Outputs . . . . . . . . . . . . . . . . . . . . . . . . .15

Fan Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Cooling Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Humidi-MiZer® Test . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Heating Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

THIRD PARTY CONTROL . . . . . . . . . . . . . . . . . . . . . 16

Cooling/Heating Control . . . . . . . . . . . . . . . . . . . . . . 16

Dehumidification Control . . . . . . . . . . . . . . . . . . . . . 16

Remote Occupancy . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Fire Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Alarm Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Economizer Damper Control . . . . . . . . . . . . . . . . . . 16

CONTROLS OPERATION . . . . . . . . . . . . . . . . . . . . . 16

Display Configuration . . . . . . . . . . . . . . . . . . . . . . . . 16

Unit Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

• THERMOSTAT CONTROL TYPE (T.CTL)

Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

General Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Temperature Setpoint Determination . . . . . . . . . . . .18

Occupancy Determination . . . . . . . . . . . . . . . . . . . .18

• LEVEL 1 PRIORITY

• LEVEL 2 PRIORITY

• LEVEL 3 PRIORITY

• INDOOR FAN OPERATION

• CONSTANT VOLUME (CV) UNITS (FTYP = 1-SPEED)

Cooling Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

• COOLING MODE CONTROL

• STAGING CONTROL

• COMPRESSOR CONTROL

• OUTDOOR FAN CONTROL

Heating Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

• HEATING MODE CONTROL

• SUPPLY-AIR TEMPERATURE SENSOR (SAT)

• STAGING CONTROL

• HEAT RELAY CONTROL

Economizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Catalog No. 0453480236-01 Printed in U.S.A. Form 48/50HC-05T Pg 1 7-19 Replaces: 48/50HC-04T

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.

• ECONOMIZER FAULT DETECTION AND DIAGNOSTICS (FDD) CONTROL

• TITLE 24 FDD CONFIGURATION POINTS

• ECONOMIZER ACTUATOR COMMUNICATION

• MINIMUM VENTILATION

• FREE COOLING

• THERMOSTAT CONTROL

• SPACE SENSOR CONTROL

Air-Side Economizer High Limit Switches Control 26

• DIFFERENTIAL DRY BULB CUTOFF CONTROL

• UNOCCUPIED FREE COOLING

• POWER EXHAUST (CV UNITS)

• POWER EXHAUST (SAV UNITS)

Indoor Air Quality (IAQ) . . . . . . . . . . . . . . . . . . . . . . 27

• IAQ (ANALOG INPUT)

• IAQ (SWITCH INPUT)

• OUTDOOR AIR QUALITY (ANALOG INPUT)

• FAN ENABLE (ANALOG IAQ SENSOR)

• FAN ENABLE (SWITCH INPUT)

Optional Humidi-MiZer® Dehumidification System 28

• DEHUMIDIFICATION DEMAND

• REHEAT MODES

• REHEAT CONTROL

• REHEAT MODE DIAGNOSTIC HELP

Temperature Compensated Start . . . . . . . . . . . . . . . 33

• SETTING UP THE SYSTEM

• TEMPERATURE COMPENSATED START LOGIC

Carrier Comfort Network® (CCN) Configuration . . 34

Demand Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Linkage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Alarm Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

• CCN ALARM BROADCAST

• ALARM RELAY OUTPUT

EnergyX® Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

• GENERAL

• COMMUNICATION

3 to 25 Ton Modulating ERV . . . . . . . . . . . . . . . . . . . 39

• OCCUPANCY

• MODES OF OPERATION

• EXHAUST CONTROL

• WHEEL STOP/JOG

• STATUS POINTS

TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . 41

Complete Unit Stoppage . . . . . . . . . . . . . . . . . . . . . . 41

Restart Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Alarms and Alerts . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

• VIEWING AND CLEARING UNIT ALARMS

• DIAGNOSTIC ALARM CODES AND POSSIBLE CAUSES

Control Module Communication . . . . . . . . . . . . . . . 49

•RED LED

• GREEN LED

• YELLOW LED

Communication Failures . . . . . . . . . . . . . . . . . . . . . . 49

Cooling Troubleshooting . . . . . . . . . . . . . . . . . . . . . 50

Humidi-MiZer™ Troubleshooting . . . . . . . . . . . . . . . 51

Economizer Troubleshooting . . . . . . . . . . . . . . . . . . 52

Title 24 FDD Status Points . . . . . . . . . . . . . . . . . . . . 52

Heating Troubleshooting . . . . . . . . . . . . . . . . . . . . . 54

• GAS HEAT (48HC UNITS)

• ELECTRIC HEAT (50HC UNITS)

Phase Loss Protection . . . . . . . . . . . . . . . . . . . . . . . 57

• PHASE REVERSAL PROTECTION

• PHASE LOSS PROTECTION

Thermistor Troubleshooting . . . . . . . . . . . . . . . . . . 57

• AIR TEMPERATURES

• REFRIGERANT TEMPERATURES

• THERMISTOR/TEMPERATURE SENSOR CHECK

• SENSOR TRIM

Transducer Troubleshooting . . . . . . . . . . . . . . . . . 63

Forcing Inputs and Outputs . . . . . . . . . . . . . . . . . . 63

Troubleshooting Units Equipped with EnergyX®

System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

• COMPLETE ERV STOPPAGE

• CHECK ALARMS

T418 OAU Filter Dirty . . . . . . . . . . . . . . . . . . . . . . . . 66

• T418 OAU MOTOR FAILURE

• T418 OAU LOW CFM

• T418 OAU GENERAL ALARM

Check Diagnostic LEDs . . . . . . . . . . . . . . . . . . . . . . 67

Communication Failures . . . . . . . . . . . . . . . . . . . . . 68

• COMM FAILURE1 – UPC TO LEN FAIL

• COMM FAILURE2 – UPC TO EXCB FAIL

On-Board Pressure Transducers . . . . . . . . . . . . . . 68

MAJOR SYSTEM COMPONENTS . . . . . . . . . . . . . . 68

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

Main Base Board (MBB) . . . . . . . . . . . . . . . . . . . . . 77

Economizer Control Board (ECB) . . . . . . . . . . . . . . 79

Integrated Gas Control (IGC) Board . . . . . . . . . . . . 80

48/50HC 04-14 Units — Low Voltage Terminal Board

(TB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

48/50HC 17-28 Units — Low Voltage Terminal Boards

(TB A and TB B) . . . . . . . . . . . . . . . . . . . . . . . . . . 82

Communication Interface Board (CIB) . . . . . . . . . . 82

Central Terminal Board (CTB) . . . . . . . . . . . . . . . . . 82

Scrolling Marquee Display . . . . . . . . . . . . . . . . . . . 83

Accessory Navigator™ Display . . . . . . . . . . . . . . . 83

Carrier Comfort Network® (CCN) Interface . . . . . . 84

Protective Devices . . . . . . . . . . . . . . . . . . . . . . . . . . 84

• COMPRESSOR PROTECTION

• EVAPORATOR FAN MOTOR PROTECTION

• CONDENSER-FAN MOTOR PROTECTION

• SATURATED SUCTION PRESSURE (SSP)

• CONDENSATE OVERFLOW SWITCH (COFS)

Field-Installed Accessories . . . . . . . . . . . . . . . . . . . 86

• SPACE TEMPERATURE SENSOR (T-55)

• SPACE TEMPERATURE SENSOR (T-56)

• SPACE TEMPERATURE SENSOR (T-58)

• SPACE TEMPERATURE SENSOR AVERAGING

• CARRIER ACCESSORY KITS

• TWO-POSITION DAMPER

• INDOOR AIR QUALITY

• OUTDOOR AIR QUALITY

• SMOKE DETECTORS

• FILTER STATUS

• FAN STATUS

• ENTHALPY SENSORS

• RETURN/SUPPLY AIR TEMPERATURE SENSOR

• SPACE HUMIDISTAT

• SPACE HUMIDITY SENSOR

Units with EnergyX® System . . . . . . . . . . . . . . . . . 88

• ENERGYX CONTROL BOARD (EXCB)

Universal Protocol Converter (UPC) . . . . . . . . . . . 92

• USER INTERFACE

• ENTHALPY WHEEL

• MODULATING FAN

• MODULATING OUTSIDE AIR DAMPER

EnergyX Options and Accessories . . . . . . . . . . . . 93

• ECONOMIZER DAMPER (FACTORY-INSTALLED

ONLY)

• FROST PROTECTION (FACTORY-INSTALLED ONLY)

• WHEEL MOTOR STATUS (FIELD-INSTALLED ONLY)

• FILTER MAINTENANCE (FIELD-INSTALLED ONLY)

• HORIZONTAL TRANSITION CURB (FIELD-

INSTALLED ONLY)

SERVICE AND MAINTENANCE . . . . . . . . . . . . . . . . 93

EnergyX System Cleaning . . . . . . . . . . . . . . . . . . . . 93

• WHEEL AND SEGMENT CLEANING

•FILTERS

• OUTDOOR-AIR INLET SCREENS

EnergyX Component Lubrication . . . . . . . . . . . . . . 94

EnergyX Wheel Drive Adjustment . . . . . . . . . . . . . . 94

EnergyX Wheel Air Seal Adjustment . . . . . . . . . . . . 94

Wheel and Segment Removal / Installation . . . . . . 94

Wheel Segment Removal / Installation . . . . . . . . . . 94

• WHOLE WHEEL REMOVAL / INSTALLATION (19 INCH WHEEL)

• WHOLE WHEEL REMOVAL/INSTALLATION (25-46 INCH WHEELS)

Outside Air and Exhaust Air Hood Removal . . . . . 96

• OUTSIDE AIR HOOD REMOVAL

• EXHAUST AIR HOOD REMOVAL

Outside Air Motorized Damper Removal . . . . . . . . 97

Outside Air and Exhaust Fan Replacement . . . . . . 97

• OUTSIDE AIR FAN REMOVAL

• EXHAUST FAN REMOVAL

APPENDIX A — LOCAL DISPLAY AND CCN

TABLES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

APPENDIC B — CONTROL MODES WITH

HUMIDI-MIZER SYSTEM AND ECONOMIZER . . . . 120

APPENDIC C — VARIABLE FREQUENCY DRIVE

(VFD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

APPENDIC D — ENERGYX

EXHAUST FAN

PERFORMANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

ENERGYX

UNIT START-UP CHECKLIST . . . . . . CL-1

injury or death. CAUTION is used to identify unsafe practices, which may result in minor personal injury or product and property damage. NOTE is used to highlight suggestions which will result in enhanced installation, reliability, or operation.

WARNING

ELECTRICAL SHOCK HAZARD Failure to follow this warning could cause personal injury

or death. Before performing service or maintenance operations on

unit, turn off main power switch to unit and install lock(s) and lockout tag(s). Ensure electrical service to rooftop unit agrees with voltage and amperage listed on the unit rating plate. Unit may have more than one power switch.

WARNING

UNIT DAMAGE HAZARD Failure to follow this caution may cause equipment damage. This unit uses a microprocessor-based electronic control

system. Do not use jumpers or other tools to short out components or to bypass or otherwise depart from recommended procedures. Any short-to-ground of the control board or accompanying wiring may destroy the electronic modules or electrical components.

IMPORTANT: This literature covers 48/50HC 04-28 models with ComfortLink Software version 3.X.

SAFETY CONSIDERATIONS

Improper installation, adjustment, alteration, service, maintenance, or use can cause explosion, fire, electrical shock or other conditions which may cause personal injury or property damage. Consult a qualified installer, service agency, or your distributor or branch for information or assistance. The qualified installer or agency must use factory-authorized kits or accessories when modifying this product. Refer to the individual instructions packaged with the kits or accessories when installing.

Follow all safety codes. Wear safety glasses and work gloves. Use quenching cloths for brazing operations and have a fire extinguisher available. Read these instructions thoroughly and follow all warnings or cautions attached to the unit. Consult local building codes and appropriate national electrical codes (in USA, ANSI/NFPA70, National Electrical Code (NEC); in Canada, CSA C22.1) for special requirements.

It is important to recognize safety information. This is the safety-alert symbol . When you see this symbol on the unit and in instructions or manuals, be alert to the potential for personal injury.

Understand the signal words DANGER, WARNING, CAUTION, and NOTE. These words are used with the safetyalert symbol. DANGER identifies the most serious hazards which will result in severe personal injury or death. WARNING signifies hazards which could result in personal

CAUTION

CUT HAZARD Failure to follow this caution may result in personal injury. Sheet metal parts may have sharp edges or burrs. Use care

and wear appropriate protective clothing, safety glasses and gloves when handling parts and servicing air conditioning equipment.

WARNING

If the information in this manual is not followed exactly, a fire or explosion may result causing property damage, personal injury or loss of life.

Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance.

WHAT TO DO IF YOU SMELL GAS

• Do not try to light any appliance.

• Do not touch any electrical switch; do not use any phone in your building.

• Immediately call your gas supplier from a neighbor’s phone. Follow the gas supplier’s instructions.

• If you cannot reach your gas supplier, call the fire department.

Installation and service must be performed by a qualified installer, service agency or the gas supplier.

AVERTISSEMENT

RISQUE D´INCENDIE OU D´EXPLOSION Si les consignes de sécurité ne sont pas suivies à la lettre,

cela peut entraîner la mort, de graves blessures ou des dommages matériels.

Ne pas entreposer ni utiliser d´essence ni autres vapeurs ou liquides inflammables à proximité de cet appareil ou de tout autre appareil.

QUE FAIRE SI UNE ODEUR DE GAZ EST DÉTECTÉE

• Ne mettre en marche aucun appareil.

• Ne toucher aucun interrupteur électrique; ne pas utiliser de téléphone dans le bâtiment.

• Quitter le bâtiment immédiatement.

• Appeler immédiatement le fournisseur de gaz en utilisant le téléphone d´un voisin. Suivre les instructions du fournisseur de gaz.

• Si le fournisseur de gaz n´est pas accessible, appeler le service d´incendie.

L´installation et l´entretien doivent être effectués par un installateur ou une entreprise d´entretien qualifié, ou le fournisseur de gaz.

GENERAL

This publication contains Start-Up, Controls, Operation, and Troubleshooting information for the 48/50HC rooftop units. (See Table 1.) These units are equipped with ComfortLink controls version 3.X or higher and use Puron

refrigerant. The specific base unit installation instructions, service manual and/or wiring label diagram may also be required in conjunction with this book as a guide to a specific unit on the roof. All the units in table 1 are Constant Volume (CV) or Staged Air Volume (SAV) units that provide stand-alone or network operation.

Table 1 — Rooftop Units

MODEL SIZE NOMINAL TONS

04 3 05 4 06 5 07 6 08 7.5 09 8.5

48/50HC

11 10 (High Efficiency) 12 10 14 12 17 15 20 18 24 20 28 25

BASIC CONTROL USAGE

ComfortLink Control

The ComfortLink control system is a comprehensive unit-management system. The control system is easy to access, configure, diagnose and troubleshoot.

The ComfortLink controller is fully communicating and cableready for connection to the Carrier Comfort Network building management system. The control provides high-speed communications for remote monitoring via the Internet. Multiple units can be linked together (and to other ComfortLink controller equipped units) using a 3-wire communication bus.

(CCN)

The ComfortLink control system is easy to access through the use of a unit-mounted display module. There is no need to bring a separate computer to this unit for start-up. Access to control menus is simplified by the ability to quickly select from 11 menus. A scrolling readout provides detailed explanations of control information. Only four, large, easy-to-use buttons are required to maneuver through the entire controls menu. The display readout is designed to be visible even in bright sunlight.

For added service flexibility, an accessory hand-held Navigator module is also available. This portable device has an extended communication cable that can be plugged into the unit’s communication network at the main control box. The Navigator display provides the same menu structure, control access and display data as is available at the unit-mounted scrolling marquee display.

Scrolling Marquee

This device is the keypad interface used to access the control information, read sensor values, and test the unit. The scrolling marquee is located in the main control box and is standard on all units. The scrolling marquee display is a 4-key, 4-character, 16-segment LED (light-emitting diode) display module. The display also contains an Alarm Status LED. (See Fig. 1.)

The display is easy to operate using 4 buttons and a group of 11 LEDs that indicate the following menu structures:

• Run Status

• Service Test

• Temperatures

•Pressures

• Set points

• Inputs

• Outputs

• Configuration

• Timeclock

• Operating Modes

•Alarms

Through the scrolling marquee, the user can access all of the inputs and outputs to check on their values and status, configure operating parameters plus evaluate the current decision status for operating modes. The control also includes an alarm history which can be accessed from the display. In addition, through the scrolling marquee, the user can access a built-in test routine that can be used at start-up commissioning and to diagnose operational problems with the unit. (See Table 2.)

MODE

Run Status

Service Test

Temperature

Pressures

Setpoints

Inputs

Outputs

Configuration

Time Clock

Operating Modes

Alarms

Alarm Status

ESCAPE

ENTER

Fig. 1 — Scrolling Marquee

Accessory Navigator™ Display

The accessory hand-held Navigator display can be used with the 48/50HC units. (See Fig. 2.) The Navigator display operates the same way as the scrolling marquee device. The Navigator display is plugged into the LEN (local equipment network) port on either CIB or the J3 port on the ECB (economizer control board).

RUN



















STATUS

Auto View of

Run Status

(VIEW)

Software

Version

Numbers

(VERS)

Control

Modes

(MODE)

Cooling

Status

(COOL)

Heating

Status

(HEAT)

Economizer

Status

(ECON)

Outside Air Unit Status

(OAU)

Component

Run Hours

(HRS)

Compressor

Starts

(STRT)

SERVICE

TEST

Service Test

Mode

(TEST)

Test Independent

Outputs

(INDP)

Test Fans

(FANS)

Test Cooling (COOL)

Test

Humidi-MiZer

(HMZR)

Test Heating

(HEAT)

Table 2 — Scrolling Marquee Mode and Menu Display Structure

TEMPERATURES PRESSURES SETPOINTS INPUTS OUTPUTS CONFIGURATION

Display Configuration

(DISP)

Unit Configuration

(UNIT)

Indoor Fan

Configuration

(I.FAN)

Cooling Configuration

(COOL)

Fan

Air

Temperatures

(AIR.T)

Refrigerant

Temperatures

(REF.T)

Thermostat

Inputs

(STAT)

General Inputs

(GEN.I)

Air Quality

Inputs

(AIR.Q)

Outputs (FANS)

Cool Outputs (COOL)

Heat Outputs (HEAT)

Economizer

Outputs (ECON)

Alarm Relay

(ALRM)

Supply Fan VFD

(S.VFD)

Humidi-MiZer Configuration

(HMZR)

Heating Configuration

(HEAT)

Economizer

Configuration

(ECON)

Air Quality Cfg.

(AIR.Q)

Outside Air Unit

Configuration

(OAU)

Alarm Relay Config.

(ALM.O)

Sensor

Calibration

(TRIM)

TIME

CLOCK

Time of Day

(TIME)

Month, Date,

Day and Year

(DATE)

Daylight Savings

Time

(DST)

Local Time

Schedule

(SCH.L)

Local

Holiday

Schedules

(HOL.L)

OPERATING

MODES

Control Modes

(MODE)

Cool

Mode

Diagnostic

(COOL)

Heat

Mode

Diagnostic

(HEAT)

Economizer

Diagnostic

(ECON)

Outside Air

Unit

Diagnostic

(OAU)

Demand

Listing

(DMD.L)

ALARMS

Reset All

Current Alarms

(R.CURR)

Currently

Active Alarms (CURR)

Reset

Alarm History

(R.HIST)

Currently

Active Alarms (CURR)

Alarm History

(HIST)

Com for t Li nk

N A

VIGATOR

TIME EW

12 . 58

LWT

54.6° F

SETP

44.1 °F

44.0°F

Ala

Sta

n Sta

tus

Service Te

Temp

erature

ressures

Setpoints

Inpu

Outp

uts

Con

fig

tion

Time Clo

E S C

Oper

ating

Mod

Alarms

ENTER

Fig. 2 — Accessory Navigator Display

Operation

All units are shipped from the factory with the scrolling marquee display, which is located in the main control box. (See Fig. 1.) In addition, the ComfortLink control also supports the use of the handheld Navigator display.

Both displays provide the user with an interface to the Com- fortLink control system. The displays have up and down arrow

CCN Configuration

(CCN)

keys, an ESCAPE key and an ENTER key. These keys are used to navigate through the different levels of the display structure. The Navigator display and the scrolling marquee operate in the same manner, except that the Navigator display has multiple lines of display and the scrolling marquee has a single line. All further discussions and examples in this document will be based on the scrolling marquee display. See Table 2 for the menu structure.

The four keys are used to navigate through the display structure, which is organized in a tiered mode structure. If the buttons have not been used for a period, the display will default to the AUTO VIEW display category as shown under the RUN STATUS category. To show the top-level display, press the ESCAPE key until a blank display is shown. Then use the up and down arrow keys to scroll through the top-level categories. These are listed in Appendix A and will be indicated on the scrolling marquee by the LED next to each mode listed on the face of the display.

When a specific mode or sub-mode is located, push the ENTER key to enter the mode. Depending on the mode, there may be additional tiers. Continue to use the up and down keys and the ENTER keys until the desired display item is found. At any time, the user can move back a mode level by pressing the ESCAPE key. Once an item has been selected the display will flash showing the item, followed by the item value and then followed by the item units (if any).

Items in the Configuration and Service Test modes are password protected. The display will flash PASS and WORD when

required. Use the ENTER and arrow keys to enter the four digits of the password. The default password is 1111.

Pressing the ESCAPE and ENTER keys simultaneously will scroll an expanded text description across the display indicating the full meaning of each display point. Pressing the ESCAPE and ENTER keys when the display is blank (MODE LED level) will return the display to its default menu of rotating AUTO VIEW display items. In addition, the password will need to be entered again before changes can be made.

Changing item values or testing outputs is accomplished in the same manner. Locate and display the desired item. If the display is in rotating auto-view, press the ENTER key to stop the display at the desired item. Press the ENTER key again so that the item value flashes. Use the arrow keys to change the value of state of an item and press the ENTER key to accept it. Press the ESCAPE key and the item, value or units display will resume. Repeat the process as required for other items.

There are some points that can be forced from the scrolling marquee or the Navigator display. If the user needs to force a variable, follow the same process as when editing a configuration parameter. A forced variable, regardless where the force has come from will be displayed with a blinking “.” on a scrolling marquee and a blinking “f” on a Navigator display following its value. For example, if economizer commanded position (EC.CP) is forced, the Navigator display shows “80f”, where the “f” is blinking to signify a force on the point. The scrolling marquee display shows “80.” Where the “.” is blinking to signify a force on the point. Remove the force by selecting the point that is forced with the key ENTER and then pressing the up and down arrow keys simultaneously. Depending on the unit model, factory-installed options and field-installed accessories, some of the items in the various Mode categories may not apply.

System Pilot™ and Touch Pilot™ Devices

The System Pilot device (33PILOT-01) and Touch Pilot device (33CNTPILOT) can be used as CCN communication user-interfaces. These devices can be put on the CCN bus and addressed to communicate with any other device on the network. Unlike the scrolling marquee and Navigator display, these pilots read the unit’s CCN tables and its CCN points can be monitored, forced, or configured. The Pilot devices can be used to install and commission a 3V zoning system, linkage compatible air source, universal controller, and all other devices operating on the Carrier communicating network.

Additionally, the System Pilot device can serve as a wall-mounted temperature sensor for space temperature measurement. The occupant can use the System Pilot device to change set points. A security feature is provided to limit access of features for unauthorized users. See Fig. 3 for System Pilot device details.

CCN Tables and Display

In addition to the unit-mounted scrolling marquee display, the user can also access the same information through the CCN tables by using the Service tool or other CCN programs/devices. The variable names used for the CCN tables and the scrolling marquee menus may be different and more items may be displayed in the CCN tables. Details on the CCN tables are included with the local display menus in Appendix A. Appendix A is structured towards the organization of the local display (scrolling marquee) menus. Because of the variety of CCN programs and devices, the CCN tables, sub-tables, and points are referenced within that organization.

NAVIGATE/ EXIT

SCROLL

PAGE

MODIFY/ SELECT

Fig. 3 — System Pilot User Interface

Force Hierarchy

There is a hierarchy in CCN with regards to forcing a point. Programs and devices write a force at different priority levels. A higher level (smaller number, 1 being the highest) will override a lower level force. The scrolling marquee uses a Control Force at level 7. The Navigator writes a Service Force which is level 3. System Pilot and Touch Pilot devices write Supervisor Forces at level 4. Network programs can be set to write different level priority forces.

Generic Status Display Table

The GENERIC points table allows the service/installer the ability to create a custom table in which up to 20 points from the 5 CCN categories (Points, Config, Service-Config, Set Point, and Maintenance) may be collected and displayed.

In the Service-Config table section, there is a table named “GENERICS.” This table contains placeholders for up to 20 CCN point names and allows the user to decide which points are displayed in the GENERIC points sub-table under the status display table. Each one of these placeholders allows the input of an 8-character ASCII string. Using a CCN interface, enter the Edit mode for the Service-Config table “GENERICS” and enter the CCN name for each point to be displayed in the custom points table in the order they will be displayed. When done entering point names, download the table to the rooftop unit control.

IMPORTANT: The computer system software (ComfortVIEW, Service Tool, etc.) that is used to interact with CCN controls, always saves a template of items it considers as static (e.g., limits, units, forcibility, 24-character text strings, and point names) after the software uploads the tables from a control. Thereafter, the software is only concerned with run time data like value and hardware/force status. With this in mind, it is important that anytime a change is made to the Service-Config table “GENERICS” (which in turn changes the points contained in the GENERIC point table), that a complete new upload be performed.

This requires that any previous table database be completely removed first. Failure to do this will not allow the user to display the new points that have been created and the CCN interface will have a different table database than the unit control.

Conventions Used in This Manual

The following conventions for discussing configuration points for the local display (scrolling marquee or Navigator accessory) will be used in this manual.

Point names will be written with the Mode name first, then any submodes, then the point name, each separated by an arrow symbol (). Names will also be shown in bold and italics. As an example, the Thermostat Control Type which is located in the Configuration mode, and Unit sub-mode would be written as Configuration

This path name will show the user how to navigate through the local display to reach the desired configuration. The user would scroll through the modes and sub-modes using the up and down keys. The arrow symbol in the path name represents pressing ENTER to move into the next level of the menu structure.

When a value is included as part of the path name, it will be shown at the end of the path name after an equals sign. If the value represents a configuration setting, an explanation will be shown in parenthesis after the value. As an example, Configu-

ration



UNITT.CTL = 1 (1 Stage Y1).

Pressing the ESCAPE and ENTER keys simultaneously will scroll an expanded text description of the point name across the display. The expanded description is shown in the local display tables but will not be shown with the path names in text.

The CCN point names are also referenced in the local display tables for users configuring the unit with CCN software instead of the local display. See Appendix A of this manual.



UNITT.C TL .

START-UP

IMPORTANT: Do not attempt to start unit, even momentarily, until all items on the Start-Up Checklist (see CL-1) and the following steps have been read/completed.

Unit Preparation

Check that unit has been installed in accordance with these installation instructions and all applicable codes.

Compressor Mounting

Compressors are internally spring mounted. Do not loosen or remove compressor hold-down bolts.

Refrigerant Service Ports

Each independent refrigerant system has a total of 3 Schradertype service gauge ports per circuit. One port is located on the suction line, one on the compressor discharge line, and one on the liquid line. Be sure that caps on the ports are tight.

Crankcase Heater(s)

Compressor crankcase heater operation varies depending on the unit size and type. In general for all units, the crankcase heaters are energized if there is power to the unit and the compressor is not operating.

IMPORTANT: Unit power must be on for 24 hours prior to start-up. Otherwise, damage to compressor may result.

Compressor Rotation

CAUTION

EQUIPMENT DAMAGE HAZARD Failure to follow this caution may result in damage to the

unit. DO not bypass the VFD while running the motor. Do not

change VFD parameter associated with motor characteristics, these are factory programmed for motor protection. Damage to the motor or the VFD can occur.

CAUTION

UNIT DAMAGE HAZARD Failure to follow this caution may result in unit damage. Improper wiring will cause compressor stoppage and

alarm. Correct wiring by switching leads as indicated below.

On 3-phase units, it is important to be certain the compressors are rotating in the proper direction. To determine whether or not compressors are rotating in the proper direction, use a phase-rotation meter on the unit input power to check for L1L2-L3 or clockwise rotation or use the Service Test mode to energize a compressor. If the compressor is rotating in the wrong direction, the controls will stop the compressor and display alarm for “Circuit x Failure to Pressurize” where x is the corresponding A or B compressor circuit.

NOTE: Indoor or outdoor fan rotation direction may not indicate proper input power phase sequence, as some 3-phase units use single-phase fan motors.

To correct the wrong compressor rotation direction, perform the following procedure:

1. Turn off power to the unit and lock out the power.

2. Switch any two of the incoming unit power leads.

3. Turn on power to the unit.

4. Verify corrected compressor rotation.

Power Supply

All 208/230-v units are factory wired for 230-v power supply. If the 208/230-v unit is to be connected to a 208-v power supply, the transformers must be rewired by moving the wire from the 230-volt connection and moving to the 200-volt terminal on the primary side of the transformer. Refer to unit label diagram for additional information.

Internal Wiring

Check all electrical connections in unit control boxes; tighten as required. See Fig. 4 and 5 for panel and filter locations.

Evaporator Fan

The evaporator fan should be checked and may need to be adjusted for specific applications. The 48/50HC04-06 size units can have a direct drive Electronic Commutated Motor (ECM) fan system; all other units have a belt drive motor. The belt drive motor can also be powered from an optional Variable Frequency Drive (VFD). Refer to the unit product data for Fan Performance tables and physical data.

48/50HC 04-06 UNITS WITH DIRECT DRIVE FANS The ECM has 5 speed taps to allow a range of fan perfor-

mance. The ComfortLink control has 1 output wire to connect to 1 tap. From the factory the control wire is connected to the first tap. The speed taps increase the speed the higher the tap number, so the first tap is the lowest speed and tap 5 is the highest speed.

BELT DRIVE UNITS The fan belt and variable pulleys are factory installed and set,

but may need to be adjusted for specific applications. Check the fan to ensure its rotation is in the proper direction before adjusting performance. To alter fan performance, adjust the pulley settings to provide the applications full load design air flow. Set the indoor fan pulley to the application design point CFM for heating and cooling so that the CFM is not lower than the minimum CFM allowed in the product data.

BELT DRIVE UNITS WITH A VFD The fan belt and variable pulleys are factory installed and set,

but may need to be adjusted for specific applications. Check the fan to ensure its rotation is in the proper direction before adjusting performance. To alter fan performance, first adjust the pulley settings to provide the applications full load design air flow when running at the Supply Fan Maximum Speed (Configuration can then be adjusted with Fan Speed - Free Cool Lo (Configu-

ration



uration tion



I.FANFS.RH), and Fan Speed — Ventilation (Con-

figuration

application design point CFM for heating and cooling at 100% fan speed so that the CFM is not lower than the minimum CFM allowed in the product data. If the exact CFM cannot be set by the half turn pulley settings then adjust the Supply Fan Maximum Speed (FS.MX) to fine tune the CFM to the application requirements. The VFD’s settings should not be used for adjusting fan performance. Specific VFD information can be found in Appendix C.

IMPORTANT: The Supply Fan Maximum Speed (FS.MX) RPM must not produce a supply CFM that is lower than the minimum CFM allowed in the product data for heating and cooling.

For belt drive units with a power exhaust option, the controls require an accurate supply duct CFM at the unit design point where the indoor fan will run at the Supply Fan Maximum Speed (FS.MX) for proper operation. The supply duct CFM is configured by the Indoor Fan Max Speed CFM (Configura-

tion



ECONIDF.C). Default values for Indoor Fan Max

Speed CFM (IDF.C) are generally set per chassis and should be changed. It is preferred to use the supply duct CFM from an air balance report to configure the Indoor Fan Max Speed CFM



UNITFS.MX). The unit operating speeds

I.FANFS.E1), Fan Speed - Mech Cooling (Config-



I.FANFS.CL), Fan Speed - Reheat 2 (Configura-



I.FANFS.VN). Set the indoor fan pulley to the

(IDF.C). If an air balance report is not available, then use the fan tables to determine Fan Max Speed CFM (IDF.C). When using the fan tables to determine Fan Max Speed CFM (IDF.C) set Economizer Position Test (Service Test to 0 (Economizer Damper Closed) and Indoor Fan Speed Test (Service Test mum Speed (FS.MX). Measure the supply to return duct static pressure difference and indoor fan RPM. Make correction to static pres sure for all options installed in the unit per the accessory pressure drop table. Determine Indoor Fan Max Speed CFM (IDF.C) on the fan table where the corrected static pres- sure and RPM cross.



FAN SF. S P D ) equal to Supply Fan Maxi-



INDPECON)

Condenser Fans and Motors

Condenser fans and motors are factory set.

Return-Air Filters

Check that correct filters are installed in filter tracks (see Physical Data table in Installation Instructions). Do not operate unit without return-air filters.

Outdoor-Air Inlet Screens

Outdoor-air inlet screens must be in place before operating unit.

Accessory Installation

Check to make sure that all accessories including space thermostats and sensors have been installed and wired as required by the instructions and unit wiring diagrams.

Orifice Change (48HC)

This unit is factory assembled for heating operation using natural gas at an elevation from sea level to 2000 ft.

Use accessory high altitude kit when installing this unit at an elevation of 2000 to 7000 ft. For elevations above 7000 ft, refer to High Altitude section to identify the correct orifice size for the elevation. Purchase these orifices from your local Carrier dealer. Follow instructions in accessory Installation Instructions to install the correct orifices.

Use accessory LP (liquid propane) gas conversion kit when converting this unit for use with LP fuel usage for elevations up to 7000 ft. For elevations above 7000 ft, refer to High Altitude section to identify the correct orifice size for the elevation. Purchase these orifices from your local Carrier dealer. Follow instructions in accessory Installation Instructions to install the correct orifices.

Fig. 4 — 48/50HC SRT Units, Panel and Filter Locations (48HC*06 Unit Shown)

INDOOR BLOWER ACCESS PAN EL

CONTROL BOX ACCESS PANEL

GAS SECTION ACCESS PANEL

INDOOR COIL ACCESS PANEL

FILTER ACCESS PANEL

UNIT BACKUNIT FRONT

INDOOR BLOWER ACCESS PANEL

OUTDOOR AIR SCREEN (HIDDEN)

GAS SECTION

CONTROL BOX ACCESS PANEL

FILTER AND INDOOR COIL ACCESS PANEL

ACCESS PANEL

Fig. 5 — 48/50HC MRT Units, Panel and Filter Locations (48HC*17 Unit Shown)

Gas Heat (48HC)

Inspect the gas heat section of the unit. Verify the number of burners match the number of heat exchanger openings and the burner assembly is properly aligned. If the orifices were changed out for elevation or Liquid Propane purposes, verify proper installation. Visually inspect other components in heat section.

Verify gas pressures before turning on heat as follows:

1. Turn off field-supplied manual gas stop, located external to unit.

2. Connect pressure gauge to supply gas tap, located on fieldsupplied manual shutoff valve. (See Fig. 6.)

MANUAL SHUT OFF

(FIELD SUPPLIED)

GAS

SUPPLY

PRESSURE TAP

(1/8˝ NPT PLUG)

UNIT

UNION

SEDIMENT TRAP

Fig. 6 — Field Gas Piping

3. Connect pressure gauge to manifold pressure tap.

4. Turn on field-supplied manual gas stop. Enter Service Test mode by setting Service Test



TEST to “ON” using the scrolling marquee display. Temporarily install the jumper wire between “R” and “W1” on TB. Use the Service Test feature to set Service Test



HEATHT.1 to ON (first

stage of heat) using the scrolling marquee.

5. After the unit has run for several minutes, verify the supply gas pressure is adequate per the base unit installation instructions. If not, adjust accordingly.

NOTE: Supply gas pressure must not exceed 13.0-in. wg.

6. Set Service Test



HEATHT.1 to OFF using scrolling

marquee.

7. Remove jumper wire if the unit will be operating under thermostat mode. The jumper must remain if a space temperature sensor (T-55, T-56, T-58, or System Pilot device) will control the unit.

8. Exit Service Test mode by setting Service Test



TEST to

“OFF” using the scrolling marquee.

Units with EnergyX® System

BASE UNIT EVAPORATOR FAN First follow the base unit instructions to balance the RTU in-

door fan. The ERV (Energy Recovery Ventilator) fans should be off during base unit fan set-up. Before start-up and testing the ERV, verify that the ComfortLink controller minimum damper positions are set to 0 and if not change them to 0. Con-

figuration →AIR.Q →AQ.MN = 0, and Configuration →ECON →MP.MX = 0. The ERV communicates with the

ComfortLink controller therefore the scrolling marquee can be used for test mode and configuration of the ERV. The following sections explain ERV testing and configuration. It is important that these configurations are set correctly in order for the ERV module to properly control the air performance. Finally, with service test disabled run unit under normal operation, verify proper supply airflow with ERV and indoor fan running.

START-UP CHECK LIST Use the EnergyX Unit Start-Up Checklist (see page CL-1) in

conjunction with the base unit Start-Up checklist from the base Controls book. Fill in all blank data entries that are applicable to the exact unit being installed. The ERV model and serial numbers are printed in the ERV control box. Save the checklist for future service and maintenance use. It is recommended that a copy of the checklist be left with the unit in the literature slot on the base unit control box access door.

ERV TEST MODE ERV Test points should be used when starting up an EnergyX

unit to verify proper ERV component operation. It can also be used for troubleshooting. To test the ERV, use the scrolling marquee to put the ComfortLink RTU into test mode. Then go to Test Independent outputs (Service Test →INDP). Table 3 shows a list of test points that can be tested as independent outputs. There are five ERV tests which can be performed separately or together while in test mode. Use the scrolling marquee to change the value of the test point. Follow the Com- fortLink Controls, Start-Up, Operation, and Troubleshooting manual for testing the base rooftop unit.

The 5 ERV specific test points are OAU 2-position Damper, OAU Wheel Test, OAU OA Fan Speed test, OAU PE Fan Speed Test and OAU Tempering Heater Test. The 2-position damper can be opened and closed with the OA.DM point. The 2-position damper accessory can be installed on the exhaust opening of the ERV. The ERV wheel motor can be turned on and off with the WHL point. The ERV’s outside air (OA.OF) and building exhaust air (OA.XF) motors can be ramped up and down during test mode their corresponding fan speed test points. Table 3 shows the test mode test points in the order they appear under test mode. Communication failures will not allow these ERV test points to be changed. The ComfortLink controller will show active alarms during test mode.

NOTE: If a 2-position damper is installed, it must be opened in test mode while operating the exhaust test.

Table 3 — Service Test Mode Independent Test

Points

ITEM EXPANSION RANGE

INDP Test Independent Outputs

ECON Economizer Position Test 0 to 100 E.CAL Calibrate Economizer Off/On PE1 Power Exhaust 1 Test Off/On PE.2 Power Exhaust 2 Test Off/On ALRM Alarm Relay Test Off/On CCH Crankcase Heat Test Off/On OA.DM OAU 2-Position Damper Close/Open WHL OAU Wheel Test 0 to 100 OA.OF OAU OA Fan Speed Test 0 to 100 OA.XF OUA PE Fan Speed Test 0 to 100 OA.HT OAU Tempering Heater Test 0 to 100

ERV CONFIGURATION The ERV configuration menu can be accessed using the Com-

fortLink controller scrolling marquee. Enter the Outside Air Unit Configurations (Configuration →OAU) menu. Table 12 shows the list of complete outside air unit configurations that can be changed and the defaults from the factory. The critical job specific configurations are listed below and should be changed at start up for the specific job site. See the operation section for details all configurations.

OAU Unoccupied Operation (U.RUN)

This allows the ERV to run during the unoccupied period when the rooftop fan is brought on.

Min DCV Outside Air CFM (DCV.M)

This sets the lowest setting for ventilation using outside air. This number sets the absolute minimum for ventilation of contaminants and CO This is only accessible if CO

generated by sources other than people.

sensors are installed and the

ComfortLink controller is configured properly. NOTE: The ERV must be equipped with optional economizer to

operate with CO

2 sensors.

Minimum Outside Air CFM (OA.MN)

This sets the outside air ventilation rate when not using a CO sensor to remove contaminants and CO2 generated by all sources in the building space. When using CO2 sensors and running DCV, this sets the maximum amount of outside air allowed for ventilation.

Power Exhaust CFM Offset (PE.OF)

This sets the offset for exhausting building air based on outside air being brought in. A negative setting causes a positive building pressure, and a positive setting causes a negative build pressure.

ERV WITH ECONOMIZER ADDITIONAL CONFIGURATIONS

There are several important ComfortLink controller configurations that impact the ERV operation when equipped with optional economizer. To change these configurations use the ComfortLink controller scrolling marquee, Navigator™ display, or a CCN communication tool. Refer to the ComfortLink Controls, Start-Up, Operation and Troubleshooting Instructions for more information on using these tools. Table 4 shows the ComfortLink controller points that impact ERV operation, with brief descriptions. These points can be found on the scrolling marquee under the economizer and air quality configuration menus (Configuration →ECON and Configuration →AIR.Q). See operation section for details on individual configurations.

ADJUSTING ERV OPTIONS The ERV can come with factory-installed frost protection and/or

an economizer (wheel bypass) damper. Other accessories can be added to the ERV in the field including but not limited to filter status, wheel status, and building pressure control. Refer to the

major components section of this manual or the specific accessory literature for more detail on these.

CONTROLS QUICK SET-UP

The following information will provide a quick guide to setting up and configuring the 48/50HC series units with ComfortLink controls. Unit controls are pre-configured at the factory for factory-installed options. Field-installed accessories will require configuration at start-up. Service Test is recommended for initial start-up. Additionally, specific job requirements may re-

quire changes to default configuration values. See the CCN and Display parameter tables and other sections of these instructions for more details. Refer to the Major System Components or accessory installation instructions for specific wiring detail.

Control Set Point and Configuration Log

During start up, accessory installation, and equipment service set points and/or configuration changes might have to be made. When setting set points or changing configuration settings, documentation is recommend. The Control Log starting on page 129. should be filled out and left with the unit at all times, a copy should also be provided to the equipment owner.

Thermostat Control

Wire accessory thermostat to the corresponding R, Y1, Y2, W1, W2, and G terminals on the field connection terminal board located at the unit control box.

The Unit Control Type configuration, Configuration



UNITU.CTL, default value is for Thermostat (2) so there

is no need to configure this item. The Thermostat Control Type, Configuration



UNITT. CT L, selects the unit response to the thermostat

inputs above. NOTE: May not be compatible with heat anticipator thermostats.

Space Temperature Sensor Control - Direct Wired (T-55 or T-56 or T-59)

Wire accessory space temperature sensor(s) to the T-55 terminals on the field connection terminal board located at the unit control box. Refer to Field-Installed Accessories section on page 86 for additional information.

Table 4 — ComfortLink Controller Configurations

DISPLAY ITEM EXPANDED TEXT DEFAULT RANGE DESCRIPTION

EC.EN Economizer Installed

MP.MX Econo Min at Max Fanspeed 0 0 to 100% Must be set to 0 so the base rooftop does not

AQ.MN Econo Min IAQ Position 0 0 to 100%

IA.CF IAQ Analog Input Configuration

IA.FN IAQ Analog Fan Configuration 0

II.CF IAQ Switch Input Configuration 0

II.FN IAQ Switch Fan Configuration 0

AQD.L AQ Differential Low 100 0 to 5000 These set the indoor air quality (IAQ) CO

AQD.H AQ Differential High 700 0 to 5000

AQD.P IAQ Override Position 100 0 to 100%

No: no FIOP Yes:

FIOP

0: no FIOP 1: FIOP

Yes/No

0=No IAQ 1=DCV 2=Override 3=Ctl Min Pos

0=Never 1=Occupied 2=Always

0=No IAQ 1=DCV N/O 2=DCV N/C 3=Override N/O 4=Override N/C

0=Never 1=Occupied 2=Always

This tells the ERV that an optional economizer is installed

use the economizer for ventilation, only free cooling

This tells the ERV if a CO installed

Tells the ERV if it can run during unoccupied for high CO

This tells the ERV if a switch is installed for

Tells the ERV if it can run during unoccupied for high CO

DCV operating range. Differential is based off a 400PPM outside CO

Sets the speed of the outside air fan during override.

value.

sensor is

sensor

switch

The Unit Control Type configuration, Configura-

tion



UNITU.CTL, must be set to Space Sensor (3). The

jumper wire in the installer’s packet must be connected between R and W1 on TB for heating mode to operate.

T-58 Communicating Room Sensor

Install the T-58 communicating thermostat. Connect the CCN communication bus from the T-58 to the CCN terminals on the field connection terminal board located at the unit control box. Configure the unit’s CCN communication element number, bus number, and baud rate. Configure the T-58 sensor’s CCN communication bus number and baud rate the same as the unit, while the element number has to be different. Configure the T-58 to send SPT to the unit’s element number. Refer to the Field-Installed Accessories section page 86 for additional information.

The Unit Control Type configuration, Configuration



UNITU.CTL, must be set to Space Sensor (3). The jump-

er wire in the installer’s packet must be connected between R and W1 on TB for heating mode to operate.

CCN Linkage Control

The CCN communication must be properly configured for the 48/50HC units and all other devices. Linkage configuration is automatically done by the supervisory CCN Linkage device.

The Unit Control Type configuration, Configuration



UNITU.CTL must be set to Space Sensor (3). The jumper

wire in the installer’s packet must be connected between R and W1 on TB for heating mode to operate.

Installation of an accessory supply air temperature (SAT) sensor in the supply duct is recommended for Linkage applications. A supply duct SAT measurement is valid for heating mode display, while the factory-standard internal SAT is not valid for heating due to its location upstream of the heating section. When installing the supply duct SAT, the heating mode display is enabled by setting Configuration to ENBL.

Installation of an accessory return air temperature (RAT) sensor in the return duct and wired to the space sensor input is recommended for Linkage applications. This will allow the unit to continue to run if Linkage communication is lost.



HEATSAT.H

System Pilot™ - Communication Space Sensor

Install the System Pilot and connect the CCN communication bus from it to the unit’s CCN connection on the low voltage terminal board. Configure the unit’s CCN communication element number, bus number, and baud rate. Refer to the System Pilot device’s installation instructions for configuring it to be used as a space temperature and attaching it to a unit.

Thermidistat Control

The thermidistat is a thermostat and humidistat combined and the inputs are provided on the field connection terminal board. The unit control type configuration, Configura-

tion



UNITU.CTL, default value is for thermostat (2) so

there is no need to configure this item. The thermostat control type configuration, Configuration the unit response to the thermostat inputs above. The space humidity switch configuration, Configuration identifies the normally open or normally closed status of this input at HIGH humidity (only on Humidi-MiZer



UNITT. CT L, selects



UNITRH.SW,

units).

Space Humidistat Control

For units with the factory Humidi-MiZer option, the humidistat input is provided on the field connection terminal board. The Space Humidity Switch configuration, Configura-

tion



UNITRH.SW, identifies the normally open or normal-

ly closed status of this input at HIGH humidity.

Relative Humidity Sensor Control

For units with the factory installed Humidi-MiZer option and the economizer option (with the ECB-economizer control board), the humidity sensor input is provided on the field connection terminal board (TB). The sensor can be used in addition to or instead of a humidistat or thermidistat. The RH Sensor on OAQ Input configuration, Configuration tifies that the sensor is being used instead of an OAQ sensor. Adjust RH setpoints as needed. Terminal LPWR is the 24vdc loop power and Terminal SPRH is the 4-20 mA signal input. Refer to the Field Installed Accessories and Humidi-MiZer Operation sections for more information.



UNITRH.S=YES, iden-

CCN Communication

Configure ConfigurationCCNCCN.A to desired element number. (Default is 1.) Configure Configuration

CCN.B to desired bus number. (Default is 0.) Configure Configuration

rate (Default is 3 = 9600 baud).



CCNBAUD to desired code number for baud



CCN



Accessories

Below are quick configuration settings for field installed accessories. If these accessories were installed by the factory, they will already be configured. See the Field-Installed Accessories section, third party control, control connection tables, and CCN or Display parameter tables for any accessories not mentioned below and any additional information on accessories.

ECONOMIZER If an economizer accessory was field installed, the unit must be

configured for it by setting Configuration to YES. The default settings for the other economizer configurations should be satisfactory. If they need to be changed, additional information about these configuration settings can be found in the Economizer section.

POWER EXHAUST If a power exhaust accessory was field installed, the unit must

be configured for it by setting Configura-

tion



ECONPE.EN to ENBL. The default settings for the

other power exhaust configurations should be satisfactory. If they need to be changed, additional information about these configurations can be found in the Power Exhaust section.

ELECTRIC HEAT If an electric heat accessory was field installed, the unit must

be configured for it by setting Configura-

tion



HEATHT.TY to a value of 2. The number of electric

heat stages must be configured by setting Configura-

tion



HEATN.HTR per the installed heater.

FIRE SHUTDOWN If a fire shutdown or smoke detector accessory was field in-

stalled, the unit must be configured for it by setting Configura-

tion



UNITFS.SW to normally open (1) or normally closed

(2) when there is not a fire alarm. Normally open (1) is the preferred configuration.

OUTDOOR ENTHALPY If an outdoor enthalpy accessory was field installed, the unit

must be configured for it by setting Configura-

tion



ECONEN.SW, identifies the normally open or nor-

mally closed status of this input when the outdoor enthalpy is low.

IAQ SWITCH If an IAQ Switch accessory was field installed, the unit must

be configured for it by setting Configuration identifies the normally open or normally closed status of this input when the indoor air quality value is low (good) and also selects the unit response to this input.



ECONEC.EN



AIR.QII.CF,

NOTE: An IAQ switch cannot be used if an enthalpy switch is already on this input.

IAQ SENSOR If an CO

configured for it by setting ConfigurationAIR.QIA.CF selects the unit response to this input. Default conversion to 0 to 2000 ppm.

OAQ SENSOR If an outdoor air quality sensor accessory was field installed,

the unit must be configured for it by setting Configura-

tion

Default conversion to 0 to 2000 ppm. FAN STATUS

If a fan status accessory was field installed, the unit must be configured for it by setting Configuration to normally open (1) or normally closed (2). Normally open (1) is the preferred configuration.

FILTER STATUS If a filter status accessory was field installed, the unit must be

configured for it by setting Configuration normally open (1) or normally closed (2). Normally open (1) is the preferred configuration.

sensor accessory was field installed, the unit must be



AIR.QOA.CF selects the unit response to this input.



UNITFN.SW



UNITFL.SW to

Programming Operating Schedules

The ComfortLink controls will accommodate up to eight different schedules (Periods 1 through 8), and each schedule is assigned to the desired days of the week. Each schedule includes an occupied on and off time. As an example, to set an occupied schedule for 8 AM to 5 PM for Monday through Friday, the user would set days Monday through Friday to ON for Period

1. Then the user would configure the Period 1 Occupied From point to 08:00 and the Period 1 Occupied To point to 17:00. To create a different weekend schedule, the user would use Period 2 and set days Saturday and Sunday to ON with the desired Occupied On and Off times.

NOTE: By default, the time schedule periods are programmed for 24 hours of occupied operation.

To create a schedule, perform the following procedure:

1. Scroll to the Configuration mode, and select CCN CONFIGURATION (CCN). Scroll down to the Schedule Number (Configuration



CCNSCH.O=SCH.N). If password

protection has been enabled, the user will be prompted to enter the password before any new data is accepted. SCH.N has a range of 0 to 99. The default value is 1. A value of 0 is always occupied, and the unit will control to its occupied set points. A value of 1 means the unit will follow a local schedule, and a value of 65 to 99 means it will follow a CCN schedule. Schedules 2-64 are not used as the control only supports one internal/local schedule. If one of the 2-64 schedules is configured, then the control will force the number back to 1. Make sure the value is set to 1 to use a local schedule.

2. Enter the Time Clock mode. Scroll down to the LOCAL TIME SCHEDULE (SCH.L) sub-mode, and press ENTER. Period 1 (PER.1) will be displayed.

3. Scroll down to the MON.1 point. This point indicates if schedule 1 applies to Monday. Use the ENTER command to go into Edit mode, and use the Up or Down key to change the display to YES or NO. Scroll down through the rest of the days and apply schedule 1 where desired. The schedule can also be applied to a holiday.

4. Configure the beginning of the occupied time period for Period 1 (OCC). Press ENTER to go into Edit mode, and the first two digits of the 00.00 will start flashing. Use the Up or Down key to display the correct value for hours, in 24-hour (military) time. Press ENTER and hour value is saved and the minutes digits will start flashing. Use the same procedure to display and save the desired minutes value.

5. Configure the unoccupied time for period 1 (UNC). Press ENTER to go into Edit mode, and the first two digits of the 00.00 will start flashing. Use the Up or Down key to display the correct value for hours, in 24-hour (military) time. Press ENTER and hour value is saved and the minutes digits will start flashing. Use the same procedure to display and save the desired minutes value.

6. The first schedule is now complete. If a second schedule is needed, such as for weekends or holidays, scroll down and repeat the entire procedure for period 2 (PER.2). If additional schedules are needed, repeat the process for as many as are needed. Eight schedules are provided. See Table 5 for an example of setting the schedule.

Table 5 — Setting an Occupied Time Schedule —Weekdays Only for 7:30 to 22:30

DISPLAY MENU SUB-SUB MODE

ENTER Local Occupancy Schedule

TIMECLOCK

SCH.L

PER.1

KEYPAD

ENTRY

ENTER OCC.1 Period Occupied Time ENTER 00.00 Scrolling stops ENTER 00.00 Hours Flash

Y 07.00 Select 7

ENTER 07.00

Y 07.30 Select 30

ENTER 07.30 Change accepted

ESCAPE OCC.1 07.30 Period Occupied Time Item/Value/Units scrolls again

B UNC.1 00.00 Period Unoccupied Time ENTER 00.00 Scrolling stops ENTER 00.00 Hours Flash

Y 22.00 Select 22

ENTER 22.00

Y 22.30 Select 30 ENTER 22.30 Change accepted

ESCAPE UNC.1 22.30 Period Unoccupied Time Item/Value/Units scrolls again

B MON.1 NO Monday In Period ENTER NO Scrolling stops

Y YES Select YES ENTER YES Change accepted

ESCAPE MON.1 YES Monday In Period Item/Value/Units scrolls again

B TUE.1 NO Tuesday In Period ENTER NO Scrolling stops

Y YES Select YES ENTER YES Change accepted

ESCAPE TUE.1 YES Tuesday In Period Item/Value/Units scrolls again

B WED.1 NO Wednesday In Period ENTER NO Scrolling stops

Y YES Select YES ENTER YES Change accepted

ESCAPE WED.1 YES Wednesday In Period Item/Value/Units scrolls again

B THU.1 NO Thursday In Period ENTER NO Scrolling stops

Y YES Select YES ENTER YES Change accepted

ESCAPE THU.1 YES Thursday In Period Item/Value/Units scrolls again

B FRI.1 NO Friday In Period ENTER NO Scrolling stops

Y YES Select YES ENTER YES Change accepted

ESCAPE FRI.1 YES Friday In Period Item/Value/Units scrolls again ESCAPE ESCAPE

ITEM DISPLAY ITEM EXPANSION COMMENT

Change accepted, minutes

flash

SERVICE TEST

The Service Test function can be used to verify proper operation of compressors, heating stages, Humidi-MiZer system, indoor fan, power exhaust fans, economizer, and the alarm relay. Use of Service Test is recommended at initial system start up and during troubleshooting (see Table 6 for point details).

Service Test mode has the following changes from normal operation:

• Outdoor air temperature limits for cooling circuits, economizer, and heating are ignored. Normal compressor time guards and other staging delays are reduced to 30 seconds or less.

• Circuit alerts are limited to 1 strike (versus 3) before changing to alarm shut down state.

• The status of ALM.N is ignored so all alerts and alarms are broadcast on CCN.

• The words “SERVICE TEST” are inserted into every alarm message.

Service test can only be turned ON/OFF at the unit display. Once turned ON, other entries may be made with the display or through CCN. To turn Service Test on, change the value of TEST to ON. To turn service test off, change the value of TEST to OFF.

NOTE: Service Test mode may be password protected. Refer to Basic Control Usage section for more information. Depending on the unit model, factory-installed options, and field-installed accessories, some of the Service Test functions may not apply.

Independent Outputs

The independent (INDP) submenu is used to change output status for the economizer, power exhaust stages, crankcase heaters, alarm relay, and outside air unit. These independent outputs can operate simultaneously with other Service Test modes. All outputs return to normal operation when Service Test is turned off. When the economizer is using the factory default Digital Control Type (Configuration



ECONE.CTL is 1 or 2) then the Econ-

omizer Calibration feature may be used to automatically check and reset the economizer actuator range of motion. Refer to the economizer operation section of more details. On EnergyX equipped units, use the outside air unit (OAU) points to test the ERV components.

Fan Test

The fans (FA NS ) submenu is used to change output status for the indoor fan. On single speed fan units the indoor fan contactor can be energized or de-energized using the IDF.1 test. For units with a VFD the indoor fan speed test (F. S P D ) is available. F. S P D runs the fan at the desired speed entered. IDF Fan Mode (F. M O D ) will run the fan at the programmed speed for each mode. IDF.2 and IDF.3 are reserved for future use.

Cooling Test

The cooling (COOL) submenu is used to change output status for the individual compressors. Compressor starts are staggered by 15 seconds. The fans (FA NS ) and heating (HEAT) service test outputs are reset to OFF for the cooling service test. Indoor fans and outdoor fans are controlled normally to maintain proper unit operation. If LEN VFD fan is configured, then the indoor fan speed will default to the Mech. Cooling Fan Speed configuration point (Configuration when one compressor is turned on. The Reduced Cool Fan Speed (F. S P D ) can only be changed while one stage is running. If more then one stage is on the actual fan speed will be 100%. F. S P D shows the reduced speed not actual speed. On single stage units, actual fan speed will be 100% when the



I.FANFS.CL)

compressor is on. All normal cooling alarms and alerts are functional.

NOTE: Circuit A will always be operated with Circuit B.

Humidi-MiZer® Test

For units with the factory Humidi-MiZer option, the HumidiMiZer (HZMR) submenu is used to change the output status to operate the circuits in different Humidi-MiZer modes or to separately test the Humidi-MiZer valve operations. Refer to the Humidi-MiZer operation section for details on these modes and valves. The fans (FAN S ), cooling (COOL), and heating (HEAT) service test outputs are reset to OFF for the HumdiMiZer service test. Indoor and outdoor fans are controlled normally to maintain proper unit operation. If LEN VFD fan is configured, then the indoor fan speed will default to the Reheat2 Fan Speed configuration point (Configura-

tion



I.FANFS.RH) when Reheat2 test is turned on. The

Reheat2 fan speed (F. S P D ) only reflects the speed setting for testing Reheat2 circuits, and can only be changed when a circuit is in Reheat2. Actual speed may be different if Reheat 1 tests are being performed. All normal cooling alarms and alerts are functional. Refer to the Humidi-MiZer operating section for more information.

NOTE: Circuit A will be operated with Circuit B.

Table 6 — Service Test Modes and Submodes

Heating Test

The heating (HEAT) submenu is used to change output status for the individual heat stages, gas or electric. The fans (FA NS ) and cooling (COOL) service test outputs are reset to OFF for the heating service test. Indoor and outdoor fans are controlled normally to maintain proper unit operation. All normal heating alarms and alerts are functional.

NOTE: Field terminal board terminal R must be connected to W1 for the heat to operate in service test. Alert number T410 will occur as a reminder if not done. If the normal unit control mode is thermostat mode, then remove the R-W1 jumper after completing service test.

THIRD PARTY CONTROL

Third party controls may interface with the unit ComfortLink controls through the connections described below. See other sections of these instructions for more information on the related unit control and configurations.

Cooling/Heating Control

The thermostat inputs are provided on the field connection terminal board. The Unit Control Type configuration, Configura-

tion



UNITU.CTL, must be 2 to recognize the below in-

puts. Terminal R is the 24vac source for the following:

• Y1 = First stage cooling

• Y2 = Second stage cooling

• W1 = First stage heating

• W2 = Second stage heating

• G = Indoor fan

Dehumidification Control

On HumidiMiZer units the HUM terminal is provided on the field connection terminal board. Humidity Switch configuration, Configuration open or normally closed status of this input at HIGH humidity.

NOTE: Dehumidification is considered a cooling function in the software.



UNITRH.SW, identifies the normally

Remote Occupancy

The remote occupancy input is provided on the field connection terminal board (TB). The Remote Occupancy Switch configuration, Configuration open or normally closed status of this input when unoccupied.

• RMOL = 24 VAC signal input

• R-2 = 24 VAC source for dry contact



UNITRM.SW, identifies the normally

Fire Shutdown

The fire shutdown input is provided for unit shutdown in response to a fire alarm or smoke detector. The Fire Shutdown Switch configuration, Configuration fies the normally open or normally closed status of this input when there is no fire alarm.

• FDWN = 24 VAC signal input



UNITFS.SW, identi-

Alarm Output

The alarm output is provided on the field connection terminal board to indicate a current alarm status. The output will be 24VAC if a current alarm exists.

• C-2 = 24 VAC common

• X = 24 VAC signal output

Economizer Damper Control

For units with the economizer option or accessory and the ECB control board, the damper position can be directly controlled through the IAQ sensor input provided on the field connection terminal board. The IAQ Analog Input configuration,

Configuration



AIR.QIA.CF will have to set to 3 (Control

Minimum Position). When IA.CF = 3, an external 4 to 20 mA source is used to move the damper 0% to 100% directly.

IAQ = 4-20mA + signal COM = 4-20mA - common NOTE: In this mode, preset minimum positions configurations

are not valid, the damper position may exceed the input position to provide economizer cooling and CO not be used for DCV control. Refer to the Indoor Air Quality operation section on page 27 for more information.

sensor input can

CONTROLS OPERATION

Display Configuration

The ConfigurationDISP submenu is used to configure the local display settings.

Metric Display (METR)

This variable is used to change the display from English units to Metric units.

Language Selection (LANG)

This variable is used to change the language of the ComfortLink display. At this time, only English is available.

Password Enable (PROT)

This variable enables or disables the use of a password. The password is used to restrict use of the control to change configurations.

Service Password (PSWD)

This variable is the 4-digit numeric password that is required if enabled.

Test Display LEDs (TEST)

This is used to test the operation of the ComfortLink display.

Unit Configuration

Many configurations that indicate what factory options and/or field accessories are installed and other common operation variables are included in Unit Configuration (Configura-

tion



UNIT). These configurations will be set in the factory for the factory-installed options (FIOPs). Field-installed accessories installed will require configuration changes. General unit and fan control configurations are also covered under this Unit Configuration menu.

Start-Up Delay (S.DLY)

This configuration sets the control start-up delay after the power is interrupted. This can be used to stagger the start-up of multiple units.

Unit Control Type (U.CTL)

This configuration defines if temperature control is based on thermostat inputs or space temperature sensor input.

• U.CTL = 2 (Thermostat) — The unit determines cooling and heating demand by the state of G, Y1, Y2,W1, and W2 inputs from a space thermostat. This value is the factory default.

• U.CTL = 3 (Space Sensor) — The unit determines cooling and heating demand based on the space temperature and the appropriate set point. Used also as Linkage configuration. The jumper wire in the installer’s packet must be connected between R and W1 on the low voltage terminal board for heating mode to operate.

THERMOSTAT CONTROL TYPE (T.CTL) This configuration applies only if Unit Control Type is Thermo-

stat (Configuration alternative cooling and Humidi-MiZer circuit staging. See the Cooling and Humidi-MiZer sections for more information. The factory default value is T.CTL = 0 (Adaptive).



UnitU.CTL = 2). The value determines

Fan Status Switch (FN.SW)

This configuration identifies if a fan status switch is installed, and what status (normally open, normally closed) the input is when the indoor fan is OFF.

Filter Status Switch (FL.SW)

This configuration identifies if a filter status switch is installed, and what status (normally open, normally closed) the input is when the filter is CLEAN.

Fire Shutdown Switch (FS.SW)

This configuration identifies if a fire shutdown switch is installed, and what status (normally open, normally closed) the input is when the fire or smoke alarm is OFF (no alarm).

Remote Occupancy Switch (RM.SW)

This configuration identifies if a remote occupancy switch is installed, and what status (normally open, normally closed) the input is when UNOCCUPIED.

SAT Settling Time (SAT.T)

This configuration sets the settling time of the supply air temperature (SAT). This tells the control how long to wait after a stage change before trusting the SAT reading. See Adaptive Thermostat Control (U.CTL = 2, T. CT L = 0) and Space Sensor Control (U.CTL = 3) within the Cooling operation section for more information. The factory default value is 240 seconds.

RAT Sensor Installed (RAT.S)

This configuration identifies if a return air temperature (RAT) sensor is installed. A YES value enables RAT display. A NO value disables RAT display. Installing an RAT sensor will allow economizer differential dry bulb control. Refer to the economizer operation for more information. RAT sensor is required for compliance with Title 24 Fault Detection and Diagnostics (FDD).

RH Sensor On OAQ Input (RH.S)

This configuration identifies if a space relative humidity sensor is installed on the outdoor air quality (OAQ) input. A YES value enables SP.RH display. If a Humdi-MiZer unit, then the unit determines dehumidification demand based on this input and the appropriate set point. A NO value disables SP.RH display and use.

Space Humidity Switch (RH.SW)

This configuration identifies if a space relative humidity switch is installed on the ENTHALPY input, and what status (normally open, normally closed) the input is when the space humidity is HIGH.

Temperature Compensated Start Cooling Factor (TCS.C)

This factor is used in the equation of the Temperature Compensated Start Time Bias for cooling. A setting of 0 minutes indicates Temperature Compensated Start in Cooling is not permitted.

Temperature Compensated Start Heating Factor (TCS.H)

This factor is used in the equation of the Temperature Compensated Start Time Bias for heating. A setting of 0 minutes indicates Temperature Compensated Start in Heating is not permitted.

Modes

The ComfortLink controls operate under a hierarchy of command structure as defined by four main elements: the System Mode, the HVAC Mode, the Occupied status, and the Unit Control Type.

The System Mode is the top level that defines three main states of the control system: Disabled, Enabled, or Test.

The HVAC Mode is the next level that defines four main states of functional operation: Disabled, Fan Only, Cool, and Heat.

The Occupied status affects set points for cooling and heating in Space Sensor control mode and operation of the economizer for indoor air quality ventilation and free cooling.

The Unit Control Type (Configuration



UNITU.CTL) de-

fines if temperature control is based on thermostat inputs or space temperature sensor input.

The general operating mode of the control and the status of some related operation lockouts are located on the display at two locations: Run Status

Modes



MODE.



MODE and Operating

System Mode (SYS)

In Run Status and Operating Modes, the current system mode is displayed with expandable text. This is an overall state of the unit.

Three states are: Unit Operation Disabled, Unit Operation Enabled, or Service Test Enabled.

HVAC Mode (HVAC)

In Run Status and Operating Modes, the current allowed HVAC mode is displayed with expandable text. This is the mode the unit decides to run in based on its inputs. There are four main HVAC modes; cooling has six different expanded texts. These modes are shown in the following tables.

Fan Mode Expanded Text Brief Description

Disabled

Fan Only

Cooling

Heating Heating Heating mode

HVAC

Operation

Disabled

Ventilation

(fan-only)

Cooling Mechanical cooling

Free Cooling Only economizer used for cooling

Unoccupied

Free Cooling

Reheat1 All running circuits in sub-cooling mode

Reheat2

Reheat1/

Reheat2

Unit is in test mode or System mode is disabled

Fan may run for ventilation

Only economizer use for cooling (occupied cooling set point active)

All running circuits in Hot Gas Reheat mode

Sub-cooling and Hot Gas Reheat active

Indoor Fan Mode (F.MOD)

This displays the mode in which the fan is running. There are 8 fan modes in total, the 1-Speed fans can only be in 1 of 2 modes (off or High). Staged Air Volume (SAV) units can utilize all 8 modes if programmed for it. The following table shows the 8 modes and a brief description for each.

Fan Mode Expanded Text Brief Description

0 OFF When the fan is off

1 High

2 Low Cool

3 Vent

4 IAQ Override

5 N/A Not available at this time

6 Dehum

7 Low Free Cool

When fan is on in 1-Speed units or at high speed on SAV units

On SAV units with 2 cooling stages, when only 1 cooling stage is requested

On SAV units, when in vent mode and fan is on

On SAV units, in any mode when IAQ override is active

On SAV units, in cooling mode, and specific conditions allow

HVAC Operation Disabled (HV.DN)

Allow disabling of HVAC mode. This is only available on a network connection and shows if the unit has been forced into the disabled status.

Cool Setpoint In Effect (EFF.C)

This shows the actual setpoint that is being used for control during cooling mode. If a 0 is displayed, then space sensor control is not being used and the unit is being controlled by a thermostat.

Heat Setpoint In Effect (EFF.H)

This shows the actual setpoint that is being used for control during heating mode. If a 0 is displayed, then space sensor control is not being used and the unit is being controlled by a thermostat.

Currently Occupied (OCC)

Displays the current state of assumed space occupancy based on unit configuration and inputs.

T med Override in Effect (T.OVR)

Displays if the state of occupancy is currently occupied due to an override.

Linkage Active (LINK)

Displays if a linkage communication “Linkage” is established between the unit and a linkage source.

Demand Limit in Effect (D.LMT)

Displays if a demand limit has been placed on the unit’s capacity.

Compressor OAT Lockout (C.LOC)

Displays if operation of one or more compressors is prevented due to outdoor temperature limit lockout.

Heat OAT Lockout (H.LOC)

Displays if heating operation is prevented due to outdoor temperature limit lockout.

Econo Cool OAT Lockout (E.LOC)

Displays if economizer operation for cooling is prevented due to outdoor temperature limit lockout.

General Operation

48/50HC units can provide cooling, dehumidification, heating, and ventilation operation. Each unit will operate under one of two basic types of control: thermostat or space temperature sensor. There are many inputs, configurations, safety factors, and conditions that ultimately control the unit. Refer to the specific operation sections for detail on a specific unit operation.

When thermostat control is enabled (Configura-

tion



UNITU.CTL = 1), the unit will operate based on dis-

crete input commands (G, Y1, Y2, W1, and W2) and there is a one minute time delay between modes and when re-entering a mode. The G command calls for ventilation, the Y1 and Y2 commands call for cooling, and the W1 and W2 commands call for heating. Thermostat Control Type (Configura-

tion



UNITT.C TL ) affects how cooling operates based on

Y1 and Y2 commands and if cooling/heating stage time guards are applied.

When space temperature sensor control is enabled (Configura-

tion



UNITU.CTL = 2), the unit will try to maintain the Space

Temperature (Temperatures tive cool and heat setpoints (Run Status EFF.H). However, to minimize unnecessary cool to heat and heat to cool changes, there is a 10 minute delay after the last stage turns off before the control will switch modes and a 1 minute delay when re-entering the last mode. Linkage operation overrides the mode changeover delay to 15 seconds. The cooling and heating Mode Select Timeguard (Operating Modes and Operating Modes time before allowing the respective mode to be entered.



AIR.TSPT) between the effec-



HEATMS.TG) show the remaining



MODEEFF.C and



COOLMS.TG

Temperature Setpoint Determination

Setpoints are used to control the unit while under space temperature sensor control. The Cool Setpoint in Effect (EFF.C) and the Heat Setpoint in Effect (EFF.H) are the points in which the unit is controlling to at a specific time. These points are read only points and change according to occupancy, the offset slider status, and network writes (Linkage or LON).

If the building is in occupied mode, the Occupied Cool Setpoint (Setpoints



OCSP) and the Occupied Heat Setpoint

(Setpoints cupied mode, the Unoccupied Cool Setpoint (Set-

points points are also separated by a Heat-Cool Set Point Gap (Setpoints

This parameter will not allow the setpoints to be set too close together, it will change the last setpoint adjusted if it is set within the GAP.

When the space sensor has a setpoint slider adjustment, the cool and heat setpoints (occupied) can be offset by sliding the bar from one side to the other. The SPT Offset Range (+/-) (Setpoints that can be added to the setpoints. With the slider in the middle, no offset is applied. Moving the slider to the “COOL” side will subtract from each setpoint, and sliding it to the “WARM” side will add to the setpoints. The slider offset being applied at any given time is displayed as Space Temperature Offset (Te m-

peratures



OHSP) are active. When the building is in unoc-



UCSP) and the Unoccupied Heat Setpoint (Set-



UHSP) are active. The heating and cooling set points



GAP) that is user configurable from 2 to 10 degrees F.



STO.R) sets the total positive or negative degrees



AIR.TSPTO).

Occupancy Determination

The building’s occupancy is affected by a number of different factors. When the unit is operating with a space temperature sensor (T-55, T-56, T-58 or T-59), occupancy affects the unit set points and the operation of the economizer. If the unit is operating under thermostat control, occupancy only affects the operation of the economizer. If the unit’s Humidi-MiZer system is being controlled by a relative humidity sensor, then occupancy will affect the RH setpoints. The factors affecting occupancy are listed below from highest to lowest priority.

LEVEL 1 PRIORITY Level 1 classification is a force/write to occupancy and can oc-

cur three ways. Listed in order of priority: force on OCCUPIED, a write to NVI_OCC, and a Linkage write. The CCN point OCCUPIED is forced via an external device such as a ComfortID controller or a service tool. When OCCUPIED is forced to YES, the unit is considered occupied, when OCCUPIED is forced to NO, the unit is considered unoccupied. If the third party protocol LON is writing to NVI_OCC, the control maps it to OCCUPIED as an input. If the unit is being controlled by Linkage, the occupancy is communicated and mapped to OCCUPIED as an input. LON and Linkage do not force the point, only write to it, therefore a force applied to OCCUPIED will override them.

If OCCUPIED is not being forced or written to, proceed to the level 2 priority.

LEVEL 2 PRIORITY Remote Occupancy Switch should be configured to either Nor-

mally Open or Normally Closed when the user would like to control the occupancy with an external switch. This switch is field-supplied (24v, single pole, single throw [SPST]). There are three possible configurations for the remote occupancy switch:

1. (Configuration

2. (Configuration Switch

3. (Configuration Switch

If the switch is configured to No Switch (0), the switch input value will be ignored and software will proceed to level 3 priority. For each type of switch, the appropriate configuration and states are listed in the table below. The Remote Occupancy Switch (INPUTS tus of the switch.



UNITRM.SW = 0) No Switch



UNITRM.SW = 1) Normally Open



UNITRM.SW = 2) Normally Closed



GEN.IRM.OC) point will show the sta-

TYPE OF SWITCH

Occupied when Closed or Unoccupied when Open

Occupied when Open or Unoccupied when Closed

SWITCH

CONFIGURATION

Normal Open (1)

Normal Closed (2)

STATE OF SWITCH

AND STATE OF

OCCUPANCY

Open and Unoccupied

Closed and Occupied

Open and Occupied

Closed and Unoccupied

NOTE: To perform remote occupancy, an Economizer Control Board must be installed in the unit.

LEVEL 3 PRIORITY The following occupancy options are determined by the state

of Occupancy Schedule Number (Configura-

tion



CCNSCH.OSCH.N) and the Global Schedule

Broadcast (Configuration

1. (Configuration



CCNBRODB.GS).



CCNSCH.OCH.N = 0)

The unit is always considered occupied and the programmed schedule is ignored. This is the factory default.

2. (Configuration



CCNSCH.OSCH.N = 1-64)

Follow the local programmed schedule. Schedules 1 to 64 are local within the controller. The unit can only store one local schedule and therefore changing this number only changes the title of the schedule table.

3. (Configuration



CCNSCH.OSCH.N = 65-99)

Follow the global programmed schedule. If the unit is configured as a Global Schedule Broadcaster (Configura-

tion



CCNBRODB.GS = YES), the unit will follow

the unit’s programmed schedule and broadcast the schedule so that other devices programmed to follow this schedule number can receive the schedule. If the unit is not programmed as a Global Schedule Broadcaster (Configu-

ration



CCNBRODB.GS = NO), the unit will

receive broadcasted schedules from a unit programmed to broadcast this schedule number. While using the programmed schedule, occupancy can be temporarily switched from unoccupied to occupied by pressing the override button for approximately 3 seconds on the T-55, T-56, T-58 or T-59 space temperature sensor. Override will only occur if SPT Override Enabled (Configura-

tion



CCNSCH.OOV.SP) is set to YES. The length

of the override period when pressing the override button is determined by the Override Time Limit (Configura-

tion



CCNSCH.OOV.TL). The hours remaining in

override is displayed as Timed Override Hours (Configu-

ration



CCNSCH.OOV.EX). This point can also be

changed from the local display or network to set or change the override period length.

INDOOR FAN OPERATION The indoor fan is required for every function of the unit and has

several configurations that effect its operation. The Indoor Fan Type configuration (Configuration



I.FANFTYP) sets the

type of fan and how it is controlled. These 48/50HC units can utilize the 1-Speed (FTYP = 0) or the LEN VFD (FTYP = 1) fan types. The Number of Speeds configuration (Configura-

tion



I.FANNSPD) is not used with fan types 1-Speed or

LEN VFD. The fan operation for these two fan types is explained in detail below. For gas heating units, the IGC fan request output (Inputs



GEN.IIGC.F) is also monitored by the MBB con-

trol. This can result in additional modification of fan delays or other operation due to safety functions of the IGC control. See the Gas Heating operation section for more details. If configured for IAQ fan operation, the fan may be turned on to satisfy air quality demands. See the Indoor Air Quality section if using IAQ (indoor air quality) accessory sensors. The fan can only run under thermostat or space sensor control if the System Mode (SYS) status is

enabled. The fan will remain on if compressors or heat relays are ever stuck on. If configured for fan status switch (FN.SW) and Shut Down on IDF Failure is enabled (Configuration



UNITIDF.F = Yes), the fan and unit will be shutdown with-

out delay on alarm. Fan off delays are honored when exiting specific HVAC modes. The Fan-off Delay delays are as follows: Mech Cool (Configuration (Configuration



HEATFOD.E), and Gas Heat (Configura-



COOLFOD.C), Elect Heat

tion HEATFOD.G). Staged Air Volume (SAV) Units (FTYP = LEN VFD)

The SAV option is a new method of controlling the supply fan in a typical constant volume rooftop unit. This control method employs a Variable Frequency Drive (VFD) to operate the supply fan at different speeds in order to achieve energy savings through reduced fan power. This method is specifically not concerned with controlling static pressure in the supply duct, but rather with setting different fan speeds for different operating conditions, such as ventilation mode or part-load mechanical cooling. This option should not be confused with a linearly variable VFD concept. The different speeds are programmed per condition; there is no linear-modulation of fan speed.

The SAV function is NOT a Variable Air Volume (VAV) function. The fan adapts its speed to one of seven based on mode and current state to satisfy a demand. The seven speeds consist of off (0%) and six configurable values. The six configurable fan speeds are: Maximum Speed (FS.MX), Ventilation (FS.VN), IAQ Override (FS.AQ), Free Cool Lo (FS.E1), Mech Cooling (FS.CL), and Reheat2 (FS.RH).

The VFD is powered direct from the distribution block or circuit breaker (CB) and is always on with power applied unless the CB is tripped. When the thermostat or space sensor control conditions require the fan on, the VFD will then ramp to desired speed. Fan speed is always calculated by evaluating the current applicable conditions. Each fan speed “mode” is evaluated independently, and the highest fan speed is used. For example, if an IAQ Override event occurs during Ventilation mode, the fan speed is set to the higher of the two (FE.VN or FS.AQ). Refer to the speed configurations below for when the fan will run at them. When first turning on the fan from 0%, it will run at max speed (FS.MX) for 1 minute.

Supply Fan Maximum Speed (FS.MX)

Max speed is the highest fan speed allowed. This is typically 100% when pulleys are set to deliver design CFM to the space per job requirement. Most safety conditions for the unit will override the fan speed to this to help protect the unit. When in heat mode this is the only speed available. In free cooling after the damper has been at max for 5 minutes, the fan will be set to max before mechanical cooling can be used and locked at max while damper is 100% and mechanical cooling is on. When running both cooling stages the fan will be set to max.

Fan Speed - Ventilation (FS.VN)

This configuration defines the fan speed used in Ventilation (fan-only) mode. Ventilation mode is when the supply fan is running, but there is no demand for heating or cooling. In thermostat mode, this is with just a G call. In space sensor control, this is when the unit is Occupied mode and the indoor fan is configured to always run while occupied (Configura-

tion



I.FANOC.FN = YES). If the indoor fan is configured

for intermittent fan (OC.FN = No), the fan will be off instead of this speed during ventilation. The economizer damper will adjust its position based on how far away this speed is from max speed.

IMPORTANT: It is important that the ventilation rate is checked after setting this speed to verify that the unit can properly ventilate the space per requirements. Adjusting this configuration or the economizer minimum setting curve should be performed to meet job requirements.

Fan Speed - IAQ Override (FS.AQ)

This configuration defines the fan speed used when an IAQ Override is active. This pertains only to the Override function of IAQ (Configuration or (Configuration



AIR.QIA.CF = 2) (Override IAQ)



AIR.QII.CF = 3 or 4) (Override N/O or

N/C), not the DCV or Minimum Position functions. When in an IAQ override condition the fan will run at this speed unless it is configured for less than the current commanded speed. When the IAQ override condition is cleared the speed will go to the next commanded speed.

Fan Speed - Free Cool Lo (FS.E1)

This configuration defines the initial fan speed used when in Free Cooling. Refer to the Economizer Controls Operation section for details on free cooling. The fan will stay at this configured speed whenever the damper is being used for free cooling. If the damper is at 100% for 5 minutes the fan will ramp to max speed. It is locked there until the actual damper position falls below 75% at which time it will ramp back down to this configured speed.

Fan Speed - Mech Cooling (FS.CL)

This configuration defines the intermediate fan speed used when one stage mechanical cooling is being requested. Fan speed is based on how many cooling stages the unit has, how many cooling stages are being requested, and how many reheat stages are being requested. If the unit only has one circuit of cooling, then the fan speed will be FS.MX whenever that stage is requested. If the unit has more than one circuit of cooling but only one is being requested, the fan speed will be set to this FS.CL. Any time more than one stage is requested the fan speed will be set to FS.MX. On Humidi-MiZer equipped units fan speed is more complex. Refer to the FS.RH and Table 7 for details.

Fan Speed - Reheat2 (FS.RH)

This configuration defines the fan speed used when Hot Gas Reheat (reheat2) is being requested. Fan speed is based on how many cooling stages the unit has, how many cooling stages are being requested, and how many reheat stages are being requested. If only reheat stages are being requested, then the fan speed will be set to FS.RH. If the unit only has one circuit of cooling, then the fan speed will be FS.MX when dehumidification and cooling is being requested. If the unit has more than one circuit of cooling and only one cooling stage is being requested, the fan speed will be set to FS.CL. Any time more than one cooling stage is requested the fan speed will be set to FS.MX. If only one cooling stage is requested and reheat is requested, then the fan speed will be set to the greater of the two configurations (FS.CL or FS.RH). (See Table 7.)

Table 7 — Cooling Fan Speed Determination

Number of

Circuits

Cooling

Stages

Required

1 0 Cooling FS.MX 1 >0 Reheat1 FS.MX 0 >0 Reheat2 FS.RH

1 0 Cooling FS.CL >1 0 Cooling FS.MX >1 >0 Reheat1 FS. MX

1 >0

0 >0 Reheat2 FS.RH

Reheat Stages

Required

HVAC Mode Fan Speed

Reheat1/ Reheat 2

FS.CL or

FS.RH

OAU Fan Boost Enable (OAFB) This configuration (Configuration



OAUOAFB) is avail-

able when the unit is equipped with a factory installed Outside Air Unit (OAU). If set to yes then the indoor fan can be used to help the

OAU if there is a low CFM alarm. When the alarm is active for 10 minutes the fan will ramp to the next highest configured

speed and wait 10 minutes. If the alarm is still active it will ramp to the next highest configured speed for 10 minutes, and so on until commanding FS.MX. If the alarm clears on its way up to max speed or at max speed, the current speed will be locked in until a standard speed driver commands something different.

CONSTANT VOLUME (CV) UNITS (FTYP = 1-SPEED) Single speed fan units are controlled by the Indoor Fan Relay 1

(Outputs



FAN SIDF.1) on the main base board (MBB),

which then operates the indoor fan contactor (IFC). The fan will be either on or off depending on the unit control type and the conditions above.

Thermostat Control

In thermostat mode, the IDF relay will be on in the following situations: fan request G in ON, cooling request Y1 or Y2 is ON, or heating request W1 or W2 is ON. If the G call is dropped or was never on with an Y1, Y2, W1, or W2 call; the IDF relay will turn off after a configurable time delay with respect to the HVAC mode that is ending.

Space Sensor Control

In Space Sensor mode, the IDF relay will be on if the unit is in Occupied mode and the indoor fan is configured to always run while occupied (Configuration



I.FANOC.FN = YES). If

the indoor fan is configured for intermittent fan (OC.FN = No), the fan will only be on when there are cooling, heating, or dehumidification stages running; or if there is an air quality demand. During the unoccupied period, the fan will operate intermittent. With intermittent fan, the IDF relay will turn off after a configurable time delay with respect to the HVAC mode that is ending.

Cooling Operation

The 48/50HC unit’s cooling operation consists of: demand, mode determination, staging request to satisfy the demand, and handling a request with the unit’s resources. These resources can include compressors, an economizer, and a reheat coil. This section covers mechanical cooling. For economizer and reheat cooling, refer to the Economizer and Humidi-MiZer sections, respectively. The unit enters a cooling mode based on a demand, decides how to satisfy the demand, executes its plan, and then leaves the cooling mode.

COOLING MODE CONTROL The cooling HVAC mode (Run Status

has six different expandable texts: Cooling, Free Cooling, Unoccupied Free Cooling, Reheat1, Reheat2, or Reheat1/Reheat2. These are all part of a general cooling mode and resemble the specific type of cooling that is being performed at any given time. All types of cooling are still performed under the general cooling function, and the expanded text is for user reference only. The control will display if it is ok to select the cooling mode (Operating Modes



COOLOK.CL= Yes).

Thermostat Control

For the unit to enter cooling mode, three things must be true: the indoor fan must be ok to use, the mode changeover time guard must be expired, and there must be a cooling demand (Y1, Y2, or dehumidification demand). The unit will remain in cooling until the cooling demand is dropped or if any of the above conditions turn false. If only a dehumidification demand exists and a heat demand (W1, W2) occurs, the unit will end cooling. The cooling mode can not officially end until all compressors are off.

Space Sensor Control

For the unit to enter cooling mode, four things must be true: the indoor fan must be ok to use, the mode changeover time guard must be expired, the unit must have a valid space temperature, and there must be a cooling or dehumidification demand. The unit will remain in cooling for at least one minute and until the



MODEHVAC=3)

cooling demand drops below -0.5°F or if any of the above conditions turn false. If only a dehumidification demand exists and the heat demand becomes greater than the Reheat Heat Setpoint Deadband (Setpoints ing. The cooling mode can not officially end until all compressors are off.

STAGING CONTROL Once the unit is in a cooling mode, it must decide what the de-

mand is and how to satisfy it. If an economizer is installed and can be used for cooling (Operating Modes Ye s ), the unit will use it first (see economizer section for its operation). If the economizer can not be used or additional cooling is needed, a mechanical cooling check is performed. OK to use Compressors? (Operating Modes set to yes when compressors are enabled and not locked out. Based on the unit control configuration, requested cooling stages (Run Status to compressor control to actually add the cooling stages.

Thermostat Control

There are two ways of requesting stages when thermostat control is enabled, Traditional Thermostat control or Adaptive control. Traditional Thermostat control is used if the Thermostat Control Type (T.C TL ) is set to 1, 2, or 3 and the economizer is not available for free cooling. If Thermostat Control (T.C TL ) is set to 0 or any time the economizer is available for free cooling, the unit will use Adaptive control for staging.

T.CTL = 0 (Adaptive Control)

Stage timers, Supply air trend, and supply air temperature limits apply when determining the request for stages. The first request (REQ.C=1) comes immediately when the Y1 input is active. The Cool Stage Increase Time (Configura-

tion



(Configuration er stage can be added or a stage can be subtracted. The SupplyAir Trend (Operating Modes next stage can be requested or should be subtracted based on the Y2 input status. If the Y1 and Y2 inputs are dropped, the supply air trend is not considered because cooling is no longer needed. If at any time the Supply-Air Temperature (SAT) falls below the Minimum Supply Air Temperature Upper Level (Configuration will not be allowed to increase. If at any time the SAT falls below the Minimum Supply Air Temperature Lower Level (Con-

figuration be reduced by one without honoring C.DEC. If SAT.L and SAT.U are configured so that they are close together, the last

stage of compressor might cycle rapidly, slowed only by its minimum on and off-time requirements.

T.CTL = 1 (1 Stage Y1) and T.CTL = 2 (2 Stage Y1)

Stage timers, Supply air trend, and supply air temperature limits do not apply when determining the request for stages. Request staging will follow the thermostat inputs directly. Y1 will request one stage. Y2 will request all stages.

T.CTL = 3 (Digital)

Space Sensor Control

Space sensor staging control is an adaptive anticipation control that weighs the actual space demand against the trend of that demand and the trend of the supply air. It also honors stage time guards and supply air limits. The demand for cooling in the space is displayed as the Cooling Demand (Run Sta-

tus



change in the space because of its current stage status. This anticipation is based on the Supply-Air Trend (Operating



COOLREQ.C) will be determined then passed

COOLC.INC) or the Cool Stage Decrease Time



COOLC.DEC) has to expire before anoth-



COOLSATSAT.U), the requested stages



COOLSATSAT.L), the requested stages will

COOLDMD.C). The control tries to anticipate the



RH.HB), the unit will end cool-



COOLOK.EC=



COOLOK.MC), will be



COOLSA.TR) decides if the

Modes



COOLSA.TR) and the Cool Demand Trend (Oper-

ating Modes

control how the space is reacting to the current running conditions and help it decide when to add or remove one stage from the requested stages. The Cool Stage Increase Time (Configu-

ration

(Configuration er stage can be added or a stage can be subtracted. If at any time the Supply-Air Temperature (SAT) falls below the Minimum Supply Air Temperature Upper Level (Configura-

tion



allowed to increase. If at any time the SAT falls below the Minimum Supply Air Temperature Lower Level (Configura-

tion



duced by one without honoring C.DEC. If SAT.L and SAT.U are configured so that they are close together, the last stage of compressor might cycle rapidly, slowed only by its minimum on and off-time requirements.

COMPRESSOR CONTROL The compressor control works hand and hand with the staging

control. As the staging control requests stages, the compressor control determines what actual compressors are available or running and tries to provide stages for what is requested. The availability of a compressor depends on time guards, circuit diagnostics, outdoor temperature, and the unit size.

The Number of Circuits (Configuration configuration tells the control how many compressors are installed on the unit. The Circuit A Lockout Temp (Configura-

tion



(Configuration the outdoor temperature in which the respective compressor is allowed to run down to. Timeguard A (Run Sta-

tus



COOLCIR.ATG.A) and Timeguard B (Run Sta-

tus



COOLCIR.BTG.B) display the time a respective

compressor has before it is available for use. Individual circuit diagnostic tests are performed during operation which may or may not allow a compressor to be used. The available stages at any given time are displayed as Available Compressors (Run

Status any given time are displayed as Actual Cooling Stages (Operating Modes tus



COOLCIR.ACMP.A) and Compressor B (Run Sta-

tus



COOLCIR.BCMP.B) are displayed on when the re-

spective compressor is running. There are time guards to protect the compressors. Compressor

Min On Time (Configuration pressor Min Off Time (Configuration ply before a compressor can be turned back on or turned off.

OUTDOOR FAN CONTROL Outdoor fans are controlled electro-mechanically, not directly

by the control system. Refer to specific unit wiring diagram and or service manual for details on how the outdoor fans operate. In general, the outdoor fan is energized with compressor A or may have partial fans operate with compressor B. HumidiMiZer units will have a Motormaster control on some or all fans.



COOLTRD.C). These trends will show the



COOLC.INC) or the Cool Stage Decrease Time



COOLC.DEC) has to expire before anoth-

COOLSATSAT.U), the requested stages will not be

COOLSATSAT.L), the requested stages will be re-



COOLN.CIR)

COOLCIR.ACA.LO) and Circuit B Lockout Temp



COOLCIR.BCB.LO) configurations set



COOLAVL.C). The actual compressors running at



COOLACT.C). Compressor A (Run Sta-



COOLMRT.C) and Com-



COOLMOT.C) ap-

Heating Operation

The 48/50HC unit’s heating operation consists of: demand, mode determination, staging request to satisfy the demand, and handling a request with the unit’s resources. These resources can be gas heat or electric heat. This section covers both gas heat units and electric heat units. The Type of Heat Installed (Configuration ry set to 1 for gas units, 2 for electric heat units with heaters installed, and 0 for electric heat units without heat installed. The unit enters a heating mode based on a demand, decides how to satisfy the demand, executes its plan, and then leaves the heating mode.



HEATHT.TY) configuration will be facto-

HEATING MODE CONTROL The heating HVAC mode (Run Status

represents both types of heating (gas or electric) under all types of control. For the unit to be allowed to enter the heat mode, heat must be enabled (HT.TY = 1 or 2), and the Outdoor Air Tempera- ture (Temperatures ing Lockout Temp (Configuration Lockout (Run StatusMODEH.LOC) displays when heat is locked out on outdoor temperature and therefore can not allow heat mode. The control will display if it is ok to select the heating mode (Operating Modes

Thermostat Control

For the unit to enter heating mode, three additional things must be true: the indoor fan must be ok to use, the mode changeover time guard must be expired, and there must be a heating demand (W1, W2). The unit will remain in heating until the heating demand is dropped or if any of the above conditions turn false. The heating mode can not officially end until all heat stages are off and the IGC fan request is dropped (on gas units).

Space Sensor Control

For the unit to enter heating mode, five additional things must be true: the indoor fan must be ok to use, the mode changeover time guard must be expired, the unit must have a valid space temperature, the W1 jumper must be installed, and there must be a heating demand. The unit will remain in heating for at least one minute and until the heat demand drops below –0.5°F or if any of the above conditions turn false. The heating mode can not officially end until all heat stages are off and the IGC fan request is dropped (on gas units without Humidi-MiZer system).

SUPPLY-AIR TEMPERATURE SENSOR (SAT) The SAT Heat Mode Sensing (Configura-

tion



HEATSATSAT.H) informs the unit if the supply air

sensor has been relocated downstream of the heat section. This configuration affects the Supply Air Temperature (Te mp era -

tures



AIR.TSAT) value displayed as listed below.

When SAT.H = DSBL, the Supply Air Temperature (Te mp era -

tures



AIR.TSAT) value on the scrolling marquee and the

CCN tables will be forced to zero when heat outputs turn ON or OFF and for 5 minutes after. The default Supply Air Temperature location is at the fan inlet, upstream of the heat section.

When SAT.H = ENBL, the Supply Air Temperature (Tem pe ra -

tures



AIR.TSAT) sensor reading is displayed at the scroll-

ing marquee and the CCN tables during heating mode. This setting should only be used if the original SAT sensor wires are removed from the Main Base Board (MBB) and replaced by an accessory SAT sensor located in the supply duct downstream of the heat section.

There are two supply air temperature limits that affect heating operation, the Maximum SAT Lower Level (Configura-

tion



HEATSATSAM.L) the Maximum SAT Upper Lev-

el (Configuration supply air temperature rises above SAM.L the heat staging will be limited to what is currently on and no additional stages can be added until the supply air temperature falls back below SAM.L. If the supply air temperature rises above SAM.U, then heating will be reduced by removing a heat stage. That stage can not be added again until the Supply Air Temperature falls below SAM.L. If the supply air temperature stays above SAM.U, then another stage will be removed after the Heat Stage Decrease Time (Configuration SAM.L and SAM.U are configured so that they are close together, the last stage of heat might cycle rapidly, slowed only by its minimum on and off-time requirements.



AIR.TOAT) must be less than the Heat-



HEAT OK.HT = Yes).



HEATSATSAM.U). Any time the



MODEHVAC=4),

HEATHT.LO). Heat OAT



HEATH.DEC). If

STAGING CONTROL Once the unit is in a heating mode, it must decide what the de-

mand is and how to satisfy. Based on the unit control configuration, requested heating stages (Run Status will be determined then passed to heat control to actually add the heating stages.

Thermostat Control

There are two ways of requesting stages when thermostat control is enabled: Traditional Thermostat control or Adaptive control. Traditional Thermostat control is used if the Thermostat Control Type (T.C TL ) is set to 1, 2, or 3. Adaptive control is used if Thermostat Control (T. CT L) is set for 0.

T.C T L = 0

Stage timers and supply air temperature limits apply when determining the request for stages. The first request (REQ.C=1) comes immediately when the W1 input is active. The Heat Stage Increase Time (Configuration Heat Stage Decrease Time (Configuration has to expire before another stage can be added or a stage can be subtracted. If at any time the Supply-Air Temperature (SAT) rises above the Maximum Supply Air Temperature Lower Level (Configuration stages will not be allowed to increase. If at any time the SAT rises above the Maximum Supply Air Temperature Upper Level (Configuration stages will be reduced by one without honoring H.DEC.

T.CTL = 1, 2 or 3

Stage timers and supply air temperature limits do not apply when determining the request for stages. Request staging will follow the thermostat inputs directly. W1 will request one stage. W2 will request all stages.

Space Sensor Control

Space sensor staging control is an adaptive anticipation control that weighs the actual space demand against the trend of that demand. It also honors stage time guards and supply air limits. The demand for heating in the space is displayed as the Heating Demand (Run Status tries to anticipate the change in the space because of its current stage status. This anticipation is based on the Heat Demand Trend (Operating Modes show the control how the space is reacting to the current running conditions and help it decide when to add or remove one stage from the requested stages. The Heat Stage Increase Time (Configuration Time (Configuration another stage can be added or a stage can be subtracted. If at any time the Supply-Air Temperature (SAT) rises above the Maximum Supply Air Temperature Lower Level (Configura-

tion

allowed to increase. If at any time the SAT rises above the Maximum Supply Air Temperature Upper Level (Configura-

tion

duced by one without honoring H.DEC. HEAT RELAY CONTROL

The heat relay control is responsible for energizing or de-energizing the MBB’s heat stage relays and works hand in hand with the staging control. As the staging control requests stages, the heat relay control determines what actual heat relays are available or energized and tries to provide stages for what is requested. The availability of a heat relays depends on heat being installed, how many stages, and time guards. The type of Heat Installed (Con-

figuration any stages to be available. The Number of Heat Stages (Configuration many heat relays can be used. Heat Stage 1 Timeguard (Run Status



tus



has before it is available for use. The available stages at any given

(Adaptive Control)



HEATSATSAM.L), the requested



HEATSATSAM.U), the requested

(Traditional Thermostat Control)



HEATDMD.H). The control



HEATTRD.H). This trend will



HEATH.INC) or the Heat Stage Decrease



HEATH.DEC) has to expire before



HEATSATSAM.L), the requested stages will not be



HEATSATSAM.U), the requested stages will be re-



HEATHT.TY) must be set for gas or electric for



HEATN.HTR) configuration tells the control how

HEATTG.H1) and Heat Stage 2 Timeguard (Run Sta- HEATTG.H2) display the time a respective heat relay



HEATREQ.H)



HEATH.INC) or the



HEATH.DEC)

time are displayed as Available Heating Stages (Run Sta-

tus



HEATAVL .H ). The actual heat relays on at any given

time are displayed as Actual Heating Stages (Operating

Modes



HEATACT.H). Heat Stage 1 Relay (Run Sta-

tus



HEATHT.1) and Heat Stage 2 Relay (Run Sta-

tusHEATHT.2) are displayed on when the respective relay

is energized. There are time guards to protect from short cycling, Heat Minimum On Time (Configuration and Heat Minimum Off Time (Configura-

tion



HEATMOT.H) apply before a heat relay can be turned

back on or turned off.

Integrated Gas Controller (IGC)

The heat staging is determined as described above and the Integrated Gas Controller (IGC) initiates the gas heat module startup. The Integrated Gas Controller (IGC) minimum on-time of 1 minute will be followed even if Heat Minimum On Time (Configuration vice Test. If the IGC temperature limit switch opens within 10 minutes of the end of the gas heat cycle, the next fan off delay will be extended by 15 seconds. The maximum delay is 3 minutes. Once modified by the IGC, the fan off delay will not change back to the configured Fan-off Delay, Gas Heat (Con-

figuration

trol. A light emitting diode (LED) is provided on the IGC to indicate status. During normal operation the LED is continuously on. See the Troubleshooting section if the LED is off or flashing. The IGC is located behind the gas section access panel door.

When the control energizes Heat Stage 1 Relay (Run Sta-

tus



HEATHT.1), power is sent to the W terminal on the

IGC board. A check is made to ensure that the rollout switch and limit switch are closed. The induced-draft motor is then energized, and when speed is proven with the Hall Effect sensor on the motor, the ignition activation period begins. The burners will ignite within 5 seconds. If the burners do not light, there is a 22-second delay before another 5-second attempt. If the burners still do not light, this sequence is repeated for 15 minutes. After the 15 minutes have elapsed, if the burners still have not lit, heating is locked out. The control will reset when the request for heat is temporarily removed. When ignition occurs, the IGC board will continue to monitor the condition of the rollout switch, limit switches, the Hall Effect sensor, as well as the flame sensor. If the unit is controlled through a room thermostat or space sensor set for fan auto, 45 seconds after ignition occurs the indoor-fan motor will be energized (and the outdoor-air dampers will open to their minimum position). If for some reason the over temperature limit opens prior to the start of the indoor fan blower, on the next attempt, the 45-second delay will be shortened to 5 seconds less than the time from initiation of heat to when the limit tripped. Gas will not be interrupted to the burners and heating will continue. Once modified, the fan on delay will not change back to 45 seconds unless power is reset to the control. When the control energizes Heat Stage 2 Relay (Run Status power is supplied to the second stage of the main gas valve. If both stage 1 and stage 2 of the gas valve close, gas will be turned off to the main burners.



HEATMRT.H) is lower and during Ser-



HEATFOD.G) unless power is reset to the con-



HEATMRT.H)



HEATHT.2),

Economizer

If an economizer is installed, then Economizer Installed (ConfigurationECONEC.EN) should be set to YES. The

economizer damper is controlled by the Econo Commanded Position (Configuration er Control Board (ECB). Feed back from the economizer actuator is output to the ECB and is displayed as Econo Actual Position (Outputs



ECONEC.CP) on the Economiz-

ECONEC.AP). The Economizer is used

for ventilation, cooling and to control the power exhaust. If the Indoor fan is not on, the economizer will not operate.

ECONOMIZER FAULT DETECTION AND DIAGNOSTICS (FDD) CONTROL

The Economizer Fault Detection and Diagnostics control can be divided into two tests:

1. Test for mechanically disconnected actuator

2. Test for stuck/jammed actuator

1. Mechanically Disconnected Actuator

The test for a mechanically disconnected actuator shall be performed by monitoring SAT as the actuator position changes and the damper blades modulate. As the damper opens, it is expected SAT will drop and approach OAT when the damper is at 100%. As the damper closes, it is expected SAT will rise and approach RAT when the damper is at 0%. The basic test shall be as follows:

1. With supply fan running take a sample of SAT at current actuator position.

2. Modulate actuator to new position.

3. Allow time for SAT to stabilize at new position.

4. Take sample of SAT at new actuator position and determine: a. If damper has opened, SAT should have decreased. b. If damper has closed, SAT should have increased.

5. Use current SAT and actuator position as samples for next comparison after next actuator move.

The control shall test for a mechanically disconnected damper if all the following conditions are true:

1. An economizer is installed.

2. The supply fan is running.

3. Conditions are good for economizing.

4. The difference between RAT and OAT > T24RATDF. It is necessary for there to be a large enough difference between RAT and OAT in order to measure a change in SAT as the damper modulates.

5. The actuator has moved at least T24ECSTS %. A very small change in damper position may result in a very small (or non-measurable) change in SAT.

6. At least part of the economizer movement is within the range T24TSTMN% to T24TSTMX%. Because the mixing of outside air and return air is not linear over the entire range of damper position, near the ends of the range even a large change in damper position may result in a very small (or non-measurable) change in SAT.

Furthermore, the control shall test for a mechanically disconnected actuator after T24CHDLY minutes have expired when any of the following occur (this is to allow the heat/cool cycle to dissipate and not influence SAT):

1. The supply fans switches from OFF to ON.

2. Mechanical cooling switches from ON to OFF.

3. Reheat switches from ON to OFF.

4. The SAT sensor has been relocated downstream of the heating section and heat switches from ON to OFF.

The economizer shall be considered moving if the reported position has changed at least ± T24ECMDB %. A very small changed in position shall not be considered movement.

The determination of whether the economizer is mechanically disconnected shall occur SAT_SEC/2 seconds after the economizer has stopped moving.

The control shall log a “damper not modulating” alert if:

1. SAT has not decreased by T24SATMD degrees F SAT_SET/2 seconds after opening the economizer at least T24ECSTS%, taking into account whether the entire movement has occurred within the range 0 to T24TSTMN%.

2. SAT has not increased by T24SATMD degrees F SAT_SET/2 seconds after closing the economizer at least T24ECSTS%, taking into account whether the entire movement has occurred within the range T24TSTMX to 100%.

3. Economizer reported position <=5% and SAT is not approximately equal to RAT. SAT not approximately equal to RAT shall be determined as follows: a. SAT<RAT-(2*2(thermistor accuracy) + 2 (SAT

increase due to fan)) or

b. SAT>RAT+(2*2(thermistor accuracy) + 2 (SAT

increase due to fan))

4. Economizer reported position >=95% and SAT is not approximately equal to OAT. SAT not approximately equal to OAT shall be determined as follows: a. SAT<OAT-(2*2(thermistor accuracy) + 2 (SAT

increase due to fan)) or

b. SAT>OAT+(2*2(thermistor accuracy) + 2 (SAT

increase due to fan))

2. Actuator Stuck or Jammed

The control shall test for a jammed actuator as follows:

• If the actuator has stopped moving and the reported position (ECONOPOS) is not within ± 3% of the commanded position (ECONOCMD) after 20 seconds, a “damper stuck or jammed” alert shall be logged.

• If the actuator jammed while opening (i.e., reported position < commanded position), a “not economizing when it should” alert shall be logged.

• If the actuator jammed while closing (i.e., reported position > command position), the “economizing when it should not” and “too much outside air” alerts shall be logged.

The control shall automatically clear the jammed actuator alerts as follows:

• If the actuator jammed while opening, when ECONOPOS > jammed position the alerts shall be cleared.

• If the actuator jammed while closing, when ECONOPOS < jammed position the alerts shall be cleared.

TITLE 24 FDD CONFIGURATION POINTS LOG.F (T24LOGFL) — “Log Title 24 Faults” — defines when

Title 24 mechanically disconnected actuator faults should be logged:

Range=YES, NO, YES — attempt to detect and log mechanically disconnect ac-

tuator NO — do not attempt to detect and log mechanically discon-

nect actuator Default=NO EC.MD (T24ECMDB) — “T24 Econ Move Detect” —

amount of change required in economizer reported position before economizer is detected as moving

Range=1-10 Default=1 EC.ST (T24ECSTS) — “T24 Econ Move SAT Test” — mini-

mum amount economizer must move in order to trigger the test for a change in SAT, i.e., the economizer must move at least T24ECSTS % before the control will attempt to determine whether the actuator is mechanically disconnected.

Range=10-20 Default=10 S.CHG (T24SATMD) — “T24 Econ Move SAT Change” —

minimum amount (in degrees F) SAT is expected to change based on economizer position change of T24ECSTS.

Range=0-5 Default=.2 E.SOD (T24SRATDF) — “T24 Econ RAT-OAT Diff” — mini-

mum difference (in degrees F) between RAT (if available) or SAT (with economizer closed and fan on) and OAT to perform mechanically disconnected actuator testing.

Range=5-20 Default=15 E.CHD (T24CHDLY) — “T24 Heat/Cool End Delay” —

amount of time (in minutes) to wait after mechanical cooling or heating has ended before testing for mechanically disconnected actuator. This is to allow SAT to stabilize at conclusion of mechanical cooling or heating.

Range=0-60 Default=25 SAT.T (SAT_SET) — “SAT Settling Time” — SAT_SET/2 is

the amount of time (in seconds) economizer reported position must remain unchanged (±T24ECMDB) before the control will attempt to detect a mechanically disconnected actuator. This is to allow SAT to stabilize at the current economizer position. This configuration sets the settling time of the supply air temperature (SAT). This typically tells the control how long to wait after a stage change before trusting the SAT reading, and has been reused for Title 24 purposes.

Range=10-900 Default=240 ET.MN (T24TSTMN) — “T24 Test Minimum Pos” — mini-

mum position below which tests for a mechanically disconnected actuator will not be performed. For example, if the actuator moves entirely within the range 0 to T24TSTMN a determination of whether the actuator is mechanically disconnected will not be made. This is due to the fact that at the extreme ends of the actuator movement, a change in position may not result in a detectable change in temperature. When the actuator stops in the range 0 to 2% (the actuator is considered to be closed), a test shall be performed where SAT is expected to be approximately equal to RAT. If SAT is not determined to be approximately equal to RAT, a “damper not modulating” alert shall be logged.

Range=0-50 Default=15 ET.MX (T24TSTMX) — “T24 Test Maximum Pos” — maxi-

mum position above which tests for a mechanically disconnected actuator will not be performed. For example, if the actuator moves entirely within the range T24TSTMX to 100 a determination of whether the actuator is mechanically disconnected will not be made. This is due to the fact that at the extreme ends of the actuator movement, a change in position may not result in a detectable change in temperature. When the actuator stops in the range 98 to 100% (the actuator is considered to be open), a test shall be performed where SAT is expected to be approximately equal to OAT. If SAT is not determined to be approximately equal to OAT, a “damper not modulating” alert shall be logged.

Range=50-100 Default=85 Range=0-10 Default=4

ECONOMIZER ACTUATOR COMMUNICATION

Economizer Position %

100

EC.MX

Minimum Fan Speed

001 0 50 75 02 52

Fan Speed %

MP.MX

MP.75

MP.50

MP.25

AQ.MN for DCV

MP.75 DCV

MP.50 DCV

MP.25 DCV

The economizer actuator used with the 48/50HC units is a Multi-Function Technology (MFT) actuator. This allows the ComfortLink system to communicate with the actuator digitally using Belimo MP protocol. The configuration Economizer Control Type (Configuration the communication method, either digital or analog, used to communicate between the Economizer Control Board and the economizer actuator.

NOTE: The power to the unit must be cycled after the Economizer Control Type (Configuration figuration parameter is changed.

E.CTL = 1 or 2 (Digital/Position or Digital/Command) When Economizer Control Type (Configura-

tion



ECONE.CTL) is set to 1, the Economizer Control

Board will communicate with the economizer actuator using the digital protocol, from Economizer Control Board plug J7-1 to actuator pin 5. The commanded position and the actuators actual position are communicated back and forth between the actuator and the Economizer Control Board. When the Economizer Control Board and actuator first initiate communication, a Control Angle (Operating Modes vided to the Economizer Control Board and defines the actuator’s range of motion. The control angle must be greater than the Min Actuator Ctrl Angle (Configura-

tion



ECONM.ANG). During this digital control, the Econ-

omizer Control Board analog 4 to 20 mA output will represent the actuator’s actual position when E.CTL = 1 or commanded position when E.CTL = 2. Because the wiring has a built-in 500-ohm resistor, the 4 to 20mA signal is converted to a 2 to 10VDC signal at the actuator.

E.CTL = 3 (Analog Control)

When E.CTL is set to 3, the Economizer Control Board will NOT communicate with the actuator using digital MFT. It will instead control the economizer actuator directly with the 4 to 20mA analog signal wired with the 500-ohm resistor producing a 2 to 10VDC signal for the actuator. While in this mode, the actuator’s built-in 2 to 10VDC feedback signal can be read as actual position any time because it is not used by the Economizer Control Board.

MINIMUM VENTILATION The economizer will open to allow ventilation when the indoor

fan is turned on and the unit is in the occupied state. The economizer damper position at any given time for ventilation is displayed as the Min Position in Effect (Run Sta-

tus



ECONEC.MP). This minimum position can be effect-

ed by the indoor fan speed (F. S P D ) and indoor air quality. On single speed units, the economizer minimum position will be equal to the ECON MIN at MAX Fan Speed (Configura-

tion



ECONMP.MX) unless Indoor air quality requests

something different. On Staged Air Volume (SAV) units, to maintain a constant air-

flow through the economizer, as the indoor fan speed decreases or increases, the damper minimum position will increase or decrease, respectively. This relationship curve is shown in Fig. 7.

Units can also be equipped with optional CO tional indoor air quality control. When unit is equipped with a return duct CO

sensor the Economizer minimum position will be recalculat-

ed based on the CO SAV units the fan speed will also be used in recalculating mini-

sensor or return duct CO2 sensor and outside air

mum position, as shown in Fig. 7. When the Commanded Fan Speed (F. S P D ) is less than the Supply Fan Maximum Speed (FS.MX) the damper will operate in the shaded area of Fig. 7 based on the IAQ Level (IAQ). See the Indoor Air Quality (IAQ) section for more details on Demand Controlled Ventilation (DCV).



ECONE.CTL) determines



ECONE.CTL) con-



ECONC.ANG) is pro-

sensors for addi-

level of the return and/or outside air. On

Fig. 7 — Minimum Damper Position Curve (on SAV

units)

The shape of the Economizer Minimum Position vs. Fan Speed curve is determined by the configuration parameters: Econ Min at 25% Fan speed (Configuration Min at 50% Fan speed (Configuration



ECONMP.25), Econ



ECONMP.50),

Econ Min at 75% Fan speed (Configura-

tion



ECONMP.75) and Econ Min at Max Fan speed (Con-

figuration



ECONMP.MX). These configurations are pre-

set at the factory for default purposes. The Econ Min at Max Fan Speed (MP.MX) should be changed based on the air bal- ance of the unit for proper ventilation. The Econ Min at 25% Fan speed (MP.25), Econ Min at 50% Fan speed (MP.50) and Econ Min at 75% Fan speed (MP.75) damper positions will be calculated and changed automatically after changing the Econ Min at Max Fan Speed (MP.MX) and Supply Fan Maximum Speed (Configuration



I.FANFS.MX).

The damper position curve can be field adjusted per application, if needed. The Econ Min at 25% Fan speed (Configura-

tion



ECONMP.25), Econ Min at 50% Fan speed (Configu-

ration



ECONMP.50) and Econ Min at 75% Fan speed

(Configuration



ECONMP.75) damper position are user

configurable and can be determined by setting the fan speed at 25, 50 and 75% and determining the damper position required to maintain the Econ Min at Max Fan Speed (Configura-

tion



ECONMP.MX) outside air CFM through the econo-

mizer outside air dampers. The default calculations programmed into the HC controls are based on a side shot economizer at 400 CFM/TON Supply Air flow with negative 0.25 in.wg H sure in the return duct. Econ Min at Max Fan Speed (FS.MN) is set by user based on minimum required outside air ventilation CFM required for the application. This procedure would be the same as if this were a CV unit with the unit running at the design point CFM. This determines the minimum position amount of outside air CFM required when the fan is running at maximum speed.

FREE COOLING The economizer will be allowed to help with cooling (Run Sta-

tus



MODEOK.EC = Yes) if the supply air temperature sen-

sor reading is valid, there are no applied lockouts, and there is not a dehumidification demand. There are four economizer lockouts that can be applied at any time. Econo Cool OAT Lockout (Operating Modes



ECONE.LOC) occurs when the Outdoor

Air Temperature (OAT) is greater than the configured Econo Cool Hi Temp Limit (Configuration



ECONEH.LO) or less

O pres-

than the configured Econo Cool Lo Temp Limit (Configura-

tion



ECONEL.LO). Econo Diff DBulb Lockout (Operating

ModesECOND.LOC) occurs when Diff Dry Bulb Control is enabled (Configuration



ECONDF.DB = Enable) and the

accessory return air temperature (RAT) is lower then the outdoor air temperature (OAT). Econo Cool Enth Lockout (Operating

Modes



ECON EN.LO) occurs when an enthalpy sensor is

installed and the Outdoor Enthalpy is HIGH. OAQ Lockout Mode (Operating Modes



ECONAQ.LO) occurs when the

outdoor air quality sensor is configured for lockout and the value is greater then the OAQ Lockout Limit (Configura-

tion



AIR.QOAQ.L). Any one of these lockouts will disable

economizer free cooling. THERMOSTAT CONTROL

If the unit is in cooling, operating under thermostat control, Y1 = ON, and the economizer is available for cooling, the economizer will control the supply-air temperature to the low cool set point (Setpoints



LCSP). When Y2 = ON, the economizer will control the supply-air temperature to high cool set point (Setpoints



HCSP). If a compressor is also being used during Free Cooling, the damper will be locked at the economizer maximum position (Configuration



ECONEC.MX).

SPACE SENSOR CONTROL If the unit is in cooling, operating under space temperature

control, the economizer is available for cooling, and no compressors are operating, the economizer will control the SAT to either Setpoints



LCSP or SetpointsHCSP (See Table 8.) If a compressor is ON, the economizer will be at the economizer maximum cooling position (Configuration



ECON



EC.MX). If the control senses low suction pressure for any active refrig-

erant circuit when the economizer is also providing cooling, the maximum allowable economizer position will be reduced. Factory default configurations have been qualified over a large range of conditions and should only be changed with care. For unit troubleshooting, factory default maximum economizer limits for this condition are provided in Table 9.

Table 8 — LCSP and HCSP Transitions for Space

Temperature Mode

CURRENT SAT SET

POINT

LCSP >0.5 HCSP HCSP <0 LCSP LCSP <–0.5 Exit Cooling

LEGEND

HCSP — High Cool Set Point LCSP — Low Cool Set Point SAT — Supply-Air Temperature

COOL DEMAND

(delta F)

NEXT SAT SET

POINT

Table 9 — Maximum Economizer Limits During Low

Suction Pressure

COOLING STAGE SIZES 04-14 SIZES 17-28

Bottom 50 50

Top 25 0

Air-Side Economizer High Limit Switches Control

DIFFERENTIAL DRY BULB CUTOFF CONTROL Econo Diff DBulb Lockout (Operating

Modes



is enabled (Configuration

ECOND.LOC) occurs when Diff Dry Bulb Control

The accessory return air temperature (RAT) will then be compared to the outdoor air temperature (OAT) based on the DF.DB setting to determine whether lockout should occur as shown in the following table:



ECONDF.DB = DISABLE).

DF.DB (DIFFBULB)

DISABLE N/A NO

RAT- 0

RAT- 2

RAT- 4

RAT- 6

OAT/RAT

Comparison

OAT>RAT YES

OAT<=RAT NO

OAT>RAT- 2 YES

OAT<=RAT-2 NO

OAT>RAT- 4 YES

OAT<=RAT-4 NO

OAT>RAT- 6 YES

OAT<=RAT-6 NO

D.LOC (DFDBLOCK)

The OAT/RAT comparison must maintain the same result for 60 consecutive seconds before D.LOC will be changed.

UNOCCUPIED FREE COOLING The unoccupied free cooling algorithm attempts to maintain

the building space half way between the Occupied Cool Set Point (Setpoints



OCSP) and Occupied Heat Set Point (Set-

pointsOHSP) using only the economizer when the condi-

tions in the building and the outdoors are suitable, during unoccupied periods. Three different configurations define this algorithm: Unoccupied Free Cooling (Configuration



ECON



UEFC), Free Cooling Preoccupancy Time (Configura- tion



ECONFC.TM), and FreeCoolLowTemp Limit (Con-

figurationECONFC.LO). UEFC = 0 (Disabled)

When UEFC = 0, unoccupied free cooling is disabled. Cooling will only occur if the space exceeds the unoccupied setpoints.

UEFC = 1 (Unoccupied)

When UEFC is set to 1, unoccupied free cooling can occur throughout the entire unoccupied period. The space temperature must be higher than the mid-point between the occupied cooling and heating setpoints.

UEFC = 2 (Preoccupancy)

When UEFC is set to 2, unoccupied free cooling can only occur when the time until the next occupied period is less than the Free Cool PreOcc Time (FC.TM) in minutes.

Free Cool PreOcc Time (FC.TM) FC.TM is the configuration that determines how many minutes

before occupancy that free cooling can occur when set for Preoccupancy (UEFC = 2).

Free Cool Low Temp Limit (FC.LO)

Unoccupied free cooling cannot occur if the Outdoor Air Temperature (Temperature



AIR.TOAT) is less than FC.LO.

POWER EXHAUST (CV UNITS) To enable power exhaust, Configuration



ECONPE.EN

must be set to ENBL. If power exhaust is enabled, Power Exhaust 1 will turn on when the economizer position is greater than the value of Configuration



ECONPE.1. Power Ex-

haust 2 will turn on when the economizer position is greater than the value of Configuration



ECONPE.2. There are

small time delays to ensure that rapid cycling does not occur. POWER EXHAUST (SAV UNITS)

To enable power exhaust, set Power Exhaust Installed (Config-

uration



ECONPE.EN) to YES. Both power exhaust fans

are wired together and are controlled by the configuration Power Exhaust Stage1 CFM (Configura-

tion



ECONPE1.C). When the Indoor Fan Max Speed

CFM (Configuration



ECONIDF.C) is set to the correct

supply duct CFM (either by fan tables or air balance report) the control will calculate the outside air CFM based on outside air damper position and Commanded Fan Speed (Out-

puts



FAN SF. S P D ) to turn on the power exhaust when the

calculated outside air CFM reaches Power Exhaust Stage1 CFM (PE1.C). The power exhaust will then turn off when the

VENTILATION FOR PEOPLE

VENTILATION FOR SOURCES

INCREASING VENTILATION

ECON MIN

AT M AX

FANSPEED

POSITION

(MP.MX)

MINIMUM

IAQ

DAMPER

POSITION

(AQ.MN)

OC EDISTUO/EDISNI007001

DIFFERENTIAL

AQ DIFFERENTIAL LOW (AQD.L)

AQ DIFFERENTIAL HIGH (AQD.H)

calculated outside air CFM falls below Power Exhaust Stage1 CFM (PE1.C). The Power Exhaust Stage2 CFM (Configura-



ECONPE2.C) is not currently used on these products.

tion

Indoor Air Quality (IAQ)

The ComfortLink control has the capability for several methods of demand ventilation control. Indoor air quality is typically measured using a CO played in parts per million (ppm). Outdoor air quality may be measured with a CO mand ventilation control, or with other sensor types for the outdoor air lockout function. The factory-installed indoor air quality CO

sensor is mounted in the return section. A field-in-

stalled indoor air quality CO return duct or directly in the occupied space, per job requirements. The indoor air quality modes of operation can be affected by configurations for indoor air quality sensor (Configura-

tion



AIR.QIA.CF), indoor air quality switch (Configura-

tion



AIR.QII.CF), outdoor air quality sensor

(Configuration



limit configurations as described below. IAQ (ANALOG INPUT)

The ComfortLink control is configured for indoor air quality sensors which provide 4 to 20 mA signal for 0 to 2000 ppm CO

. If the sensor being used has a different range, the ppm

display range must be reconfigured by entering new values for the IAQ Sensor Value at 4mA (Configura-

tion



AIR.QI.4M) and IAQ Sensor Value at 20mA (Config-

urationAIR.Q I.20M). IA.CF = 0 (No IAQ) IA.CF = 0 signifies that there is no IAQ sensor installed. The

damper will operate at the Econ Min at Max Fan Speed (Configuration



ECONMP.MX) when the fan is at Supply Fan

Maximum Speed (Configuration damper position will vary at other fan speeds as described in the Economizer section, when the space is occupied and the indoor fan is on.

IA.CF = 1 (DCV)

When IA.CF = 1, the IAQ algorithm is set for Demand Controlled Ventilation (DCV). During DCV, the damper modulates between two user configurations depending upon the relationship between the Indoor Air Quality (IAQ) and the Outdoor Air Quality (OAQ).

The lower of these two positions is referred to as the Econo Min IAQ Position (Configuration the higher is referred to as the Econ Min at Max Fan Speed (Configuration



sition (AQ.MN) should be set to an economizer position that brings in enough fresh air to remove contaminates and CO generated by sources other than people. The Econ Min at Max Fan Speed (MP.MX) should be set to an economizer position that brings in fresh air to remove contaminates and CO ated by all sources including people when the indoor fan is operating at the Supply Fan Maximum Speed (Configura-

tion



I.FANFS.MX). The Econ Min at Max Fan Speed

(MP.MX) value is the design value for maximum occupancy. The ComfortLink controls will begin to open the damper from

the Econo Min IAQ Position (AQ.MN) position when the IAQ level begins to exceed the Outdoor Air Quality (OAQ) level by a configurable amount. This amount is referred to as AQ Differential Low (Configuration differential between IAQ and OAQ reaches AQ Differential High (Configuration sition will be at the Econ Min at Max Fan Speed (MP.MX) when the indoor fan speed is at Supply Fan Maximum Speed (FS.MX). When the IAQ/OAQ differential is between AQ Differential Low (AQD.L) and AQ Differential High (AQD.H), the control will modulate the damper between Econ Min at Max Fan Speed (MP.MX) and Econo Min IAQ Position

sensor whose measurements are dis-

sensor for indoor-outdoor differential de-

sensor may be mounted in the

AIR.QOA.CF) and other related fan and



I.FANFS.MX) and the



AIR.QAQ.MN), while

ECONMP.MX). The Econo Min IAQ Po-

gener-



AIR.QAQD.L). When the



AIR.QAQD.H), the economizer po-

(AQ.MN) in a linear manner as shown in Fig. 8. At other fan speeds the economizer damper will operate in the shaded area between the two economizer position curves but at the actual fan speed as indicated by Commanded Fan Speed (Out-



FAN SF. S P D ). (See Fig. 8.)

puts

Fig. 8 — Economizer Minimum Position

IA.CF = 2 (Override IAQ)

When IA.CF = 2, the IAQ algorithm maintains the damper at Econ Min at Max Fan Speed (Configura-

tion



ECONMP.MX) when the indoor fan speed is at Sup-

ply Fan Maximum Speed (Configuration



I.FANFS.MX)

or along the curve on Fig. 8 when the indoor fan speed is at the Commanded Fan Speed (Outputs



FAN SF. S P D ) until the

override condition triggers. The override triggers when the IAQ/OAQ differential is greater than AQ Differential High (Configuration tion (Configuration



AIR.QAQD.H). The IAQ Override Posi-



AIR.QOVR.P) sets the damper posi-

tion during override. The economizer damper will return to the Econ Min at Max Fan Speed (MP.MX) or MP.MX curve at oth- er fan speeds when the IAQ/OAQ differential is less than the AQ Differential Low (Configuration



AIR.QAQD.L).

The override algorithm will operate whenever the building is occupied and the indoor fan is operating or whenever the IAQ algorithm has caused the indoor fan to operate. The IAQ Analog Fan Config (Configuration



AIR.QIA.FN) determines

whether or not the IAQ algorithm can turn on the indoor fan. If the indoor fan is not operating, the economizer position will be zero. If the override is not active and the building is unoccu-

pied, the economizer position will be zero. The damper position may exceed Econ Min at Max Fan Speed (MP.MX) or IAQ Override Position (OVR.P) to provide economizer cooling.

IA.CF = 3 (Control Minimum Position)

When IA.CF = 3, an external 4 to 20 mA source is used to set the minimum position. The 4mA signal corresponds to 0% and the 20 mA signal corresponds to 100%. In this mode, configurations such as Econ Min at Max Fan Speed (Configura-

tion



ECONMP.MX), Econo Min IAQ Position (Configu-

ration



AIR.QAQ.MN) and the economizer minimum posi-

tion and DCV minimum position curves in Fig. 7 and 8 are not used. If the indoor fan is not operating, the economizer position will be zero. The damper position may exceed the economizer minimum position to provide economizer cooling.

IAQ (SWITCH INPUT) Indoor air quality can also be measured using a switch input. For

the purpose of specifying the type of switch input, low CO els are considered normal. The IAQ switch input is defined by

lev-

the IAQ Switch Input Config (Configuration



AIR.QII.CF).

Enthalpy and IAQ are controlled by the same switch input and therefore cannot be used simultaneously.

II.CF = 0 (No IAQ)

The II.CF = 0 configuration signifies that there is no IAQ switch input. The damper will operate at the Econ Min at Max Fan Speed (Configuration



ECONMP.MX) and corre-

sponding damper position curve based on indoor fan speed when the space is occupied and the indoor fan is on.

II.CF = 1 (DCV Normally Open) or II.CF = 2 (DCV Normally Closed)

The Demand Controlled Ventilation (DCV) allows the economizer minimum position to be decreased when there is no IAQ problem. If IAQ is low, the economizer minimum position is Econo Min IAQ Position (Configuration



AIR.QAQ.MN)

when the indoor fan is operating at Supply Fan Maximum Speed (Configuration



UNITFS.MX). If IAQ is high, the

economizer minimum position is Econ Min at Max Fan Speed (Configuration



ECONMP.MX) when the indoor fan is op-

erating at Supply Fan Maximum Speed (FS.MX). If the fan speed is modulating, see Fig. 8 for higher or lower damper position setting at the specific fan speed.

II.CF = 3 (Override Normally Open) or II.CF = 4 (Override Normally Closed)

The damper override function permits absolute positioning of the economizer damper for ventilation purposes. The override is active when IAQ is high and inactive when IAQ is low. The override position is configured by the IAQ Override Position (Configuration



AIR.QOVR.P).

OUTDOOR AIR QUALITY (ANALOG INPUT) The ComfortLink control can be configured for outdoor air

quality sensors which provide a 4 to 20 mA signal corresponding to 0 to 2000 ppm CO

. If a field supplied sensor has a dif-

ferent range, the ppm display range must be reconfigured by entering new values for the OAQ Sensor Value at 4mA (Con-

figuration (Configuration



AIR.QO.4M) and OAQ Sensor Value at 20mA



AIR.QO.20M).

OA.CF = 0 (No OAQ)

This signifies that there is no outdoor air sensor installed. The default value of OAQ is 400 ppm CO

when using demand

controlled ventilation (DCV).

OA.CF = 1 (DCV)

The outdoor air quality sensor analog input is the value of OAQ for demand controlled ventilation (DCV).

OA.CF = 2 (OAQ Lockout)

The outdoor air quality analog input is only used to lock out the outdoor ventilation. The economizer commanded position is set to 0% when the CO

ppm exceeds the OAQ lockout value

configured for the OAQ Lockout Limit (Configura-

tion



AIR.QOAQ.L). The default value for OAQ Lockout

Limit (OAQ.L) is 600 ppm CO

FAN ENABLE (ANALOG IAQ SENSOR) The DCV algorithm will operate whenever the building is oc-

cupied and the indoor fan is operating or whenever the IAQ algorithm has caused the indoor fan to operate. The IAQ Analog Fan Config (Configuration



AIR.QIA.FN) determines

whether or not the IAQ algorithm can turn on the indoor fan. If the indoor fan is not operating, the economizer position will be zero. The damper position may exceed Econ Min at Max Fan Speed (Configuration



ECONMP.MX) and corresponding

damper position curve to provide economizer cooling.

IA.FN = 0 (Never) When IA.FN = 0, the IAQ algorithm can never turn on the fan.

IA.FN = 1 (Occupied)

When IA.FN =1, the IAQ algorithm will turn on the indoor fan whenever the building is occupied and IAQ/OAQ differential is greater than the Fan On AQ Differential (Configura-

tion



AIR.QDF.ON). The indoor fan will turn off when the

IAQ/OAQ differential is less than the Fan Off AQ Differential (Configuration



AIR.QDF.OF).

IA.FN = 2 (Always)

The indoor fan operation for IA.FN = 2, is the same as the operation when IA.FN =1, except the algorithm is not limited to the occupied periods only. The fan can be triggered on when the space is occupied or unoccupied.

FAN ENABLE (SWITCH INPUT) The DCV algorithm will operate whenever the building is oc-

cupied and the indoor fan is operating or whenever the IAQ algorithm has caused the indoor fan to operate. The IAQ Switch Fan Config (Configuration



AIR.QII.FN) determines



ECONMP.MX) and corresponding

damper position curve to provide economizer cooling.

II.FN = 0 (Never) When the II.FN = 0, the IAQ algorithm can never turn on fan. II.FN = 1 (Occupied)

When II.FN =1, the IAQ algorithm will turn on the indoor fan whenever the building is occupied and IAQ is high. The indoor fan will turn off when the IAQ returns to normal.

II.FN = 2 (Always)

The indoor fan operation for II.FN =2 is the same as the operation when IA.FN =1, except the algorithm is not limited to the occupied periods only. The fan can be triggered on when the space is occupied or unoccupied.

Optional Humidi-MiZer® Dehumidification System

Units with the factory-equipped Humidi-MiZer option are capable of providing multiple modes of improved dehumidification as a variation of the normal cooling cycle. The Humidi-MiZer option includes additional valves in the liquid line and discharge line of each refrigerant circuit, a reheat coil downstream of the evaporator, and Motormaster all outdoor fans. The Humidi-MiZer Equipped (Configura-

tion



HMZRREHT) configuration is factory set to Yes for

Humidi-MiZer equipped units. This enables Humidi-MiZer operating modes and service test.

Humidi-MiZer operation requires installation and configuration of either a space relative humidity sensor or a relative humidity switch input. Space Humidity Switch (Configura-

tion



UNITRH.SW) set to 1 for use of a normally open

switch or 2 for normally closed switch. The switch is wired to field connection terminal board terminal labeled HUM and the “R2” terminal. Set RH Sensor on OAQ Input (Configura-

tion



UNITRH.S) to Yes for use of a 4 to 20 mA output RH

sensor wired to field connection terminal board (TB) terminals SPRH and LPWR (for loop powered). RH Sensor Value at 4ma (Configuration



AIR.QH.4M) sets the % display for a 4mA

input from the relative humidity sensor. RH Sensor Value at 20ma (Configuration a 20mA input from the relative humidity sensor.

DEHUMIDIFICATION DEMAND When using a humidistat or switch input, the demand for de-

humidification is seen as Space Humidity Switch (In-

puts



GEN.IHUM) being Low or High. A low value

means humidity level is good and a high value means that dehumidification is needed.When using an RH sensor, the demand is based on the Space Humidity Sensor (In-

puts



AIR.QSP.RH) value compared to the Space RH

variable-speed control of some or



AIR.QH.20M) sets the % display for

Occupied Setpoint (Setpoints



RH.SP) during the occupied

period and Space RH Unoccupied Setpoint (Set-

points



RH.UN) during unoccupied periods. If the Space Humidity Sensor (SP.RH) value is above the Space RH Set- point (RH.SP), then dehumidification is needed. If the Space Humidity Sensor (SP.RH) value is below the Space RH Setpoint (RH.SP) minus the Space RH Deadband (Set-

points



RH.DB), then dehumidification is no longer needed. If the unit is configured for space sensor control (Con-

figuration Heat SP Deadband (Setpoints



UNITU.CTL = 3), then the setpoint Reheat



RH.HB) applies. This configuration sets the offset above the heating set point at which a unit in Reheat2 mode will turn off. This is a protection against over cooling the space and causing a heat demand.

NOTE: When there is a dehumidification demand, the economizer damper position is limited to its minimum damper position (Oper-

ating Mode



ECONEC.MP).

REHEAT MODES Dehumidification (reheat) is a cooling mode function. Refer to

Cooling Operation for cooling mode control. With Humidi-MiZer units there are three additional HVAC Mode (HVAC) expanded texts available for the user: Reheat1, Reheat2, and Reheat1/Reheat2. Selection of the reheat mode for each refrigerant circuit is determined by the dehumidification demand and the cooling demand. Table 10 shows the corresponding circuit mode and output status for the different demand combinations. Units with multiple circuits can operate with a combination of Reheat1 and Reheat2 circuits, as determined by the amount of space cooling demand. See Appendix B for complete tables of unit operation response to thermostat and humidity inputs.

NOTE: Compressor staging control for Humidi-MiZer units requires that circuit A always operates when circuit B is on. This applies to normal operation, service test, and for control alarm responses. This operation difference is required due to the fact that the Motormaster outdoor fan control senses circuit A only.

Table 10 — Control Modes with Humidi-MiZer System

Output and Valve States versus Circuit Mode .x = Circuit A or B identifier

Operation of the revised refrigerant circuit for each mode is described below.

NOTE: x = refrigerant circuit A or B

Normal Cooling

For 48/50HC04-12 units, refrigerant flows from the outdoor condenser through the normally open Cooling Liquid Valve (CLV.x) to the expansion device. Reheat Liquid Valve (RLV.x) and Reheat Discharge Valve (RDV.x) are closed. (See Fig. 9.) For 48/ 50HC14-28 units, refrigerant flows from the outdoor condenser through the de-energized 3-way Liquid Diverter Valve (LDV.x) to the expansion device. Reheat Discharge Valve (RDV.x) is closed. (See Fig. 10.)

Reheat 1 (Subcooling Mode)

This mode increases latent cooling and decreases sensible cooling compared to normal cooling.

For 48/50HC04-12 units, refrigerant flows from the outdoor condenser, through the normally open Reheat Liquid Valve (RLV.x), and through the reheat condenser coil to the expansion device. Cooling Liquid Valve (CLV.x) and Reheat Discharge Valve (RDV.x) are closed. (See Fig. 11.)

For 48/50HC14-28 units, refrigerant flows from the outdoor condenser, through the energized 3-way Liquid Diverter Valve (LDV.x), and through the reheat condenser coil to the expansion device. Reheat Discharge Valve (RDV.x) is closed. (See Fig. 12.)

Reheat 2 (Hot Gas ReheatMode)

This mode provides maximum latent cooling with little to no sensible capacity. This mode can operate to provide dehumidification when there is no cooling demand. Similar to Reheat 1 mode, refrigerant flows from the outdoor condenser, through the normally open Reheat Liquid Valve (RLV1.x), or through the energized 3way Liquid Diverter Valve (LDV.x), and through the reheat con- denser coil to the expansion device. Reheat Discharge Valve (RDV.x) is open which provides some compressor discharge gas to the reheat condenser to further increase the reheat of the evaporator air stream (See Fig. 13 or 14 based on unit and size).

DEMAND AND MODE OUTPUTS 48/50HC 04-12 VALVES 48/50HC 14-28 VALVES

Space

Humidity

— — No power Off Off Off Off (open) Off (open) Off (closed) Off Off (closed) Low No Off Off Off Off Off (open) On (closed) Off (closed) Off Off (closed) Low Yes Cool On Off Off Off (open) On (closed) Off (closed) Off Off (closed) High Yes Reheat1 On On Off On (closed) Off (open) Off (closed) On Off (closed) High No Reheat2 On On On On (closed) Off (open) On (open) On On (open)

Circuit

Cooling

Demand

Circuit

Mode

Circuit

Compressor

(CMP.x)

Cooling-

Reheat

Control

(CRC)*

Reheat2

Valve

(RH3.x)

CLV.x Valve

2-way

RLV.x Valve

2-way

RDV.x

Valve 2-way

RLV.x Valve

3-way

RDV.x

Valve 2-way

COMP

LIOC REZIM-IDIMUHLIOC DNOC

EVAP COIL

INDOOR ENTERING

AIR

METERING DEVICE

RLV.x

RDV.x

OUTDOOR AIR

CLOSED VALVE

OPEN VALVE

CLV.x

COMP

LIOC REZIM-IDIMUHLIOC DNOC

EVAP COIL

INDOOR ENTERING

AIR

METERING DEVICE

LDV.x

RDV.x

OUTDOOR AIR

CLOSED VALVE

OPEN VALVE

3-WAY VALVE

Fig. 9 — Normal Cooling Mode — Humidi-MiZer

System — 48/50HC 04-12

Fig. 10 — Normal Cooling Mode — Humidi-MiZer System

48/50HC 14-28

COMP

LIOC REZIM-IDIMUHLIOC DNOC

EVAP COIL

INDOOR ENTERING

AIR

METERING DEVICE

RLV.x

RDV.x

OUTDOOR AIR

CLOSED VALVE

OPEN VALVE

CLV.x

COMP

LIOC REZIM-IDIMUHLIOC DNOC

EVAP COIL

INDOOR ENTERING

AIR

METERING DEVICE

LDV.x

RDV.x

OUTDOOR AIR

CLOSED VALVE

OPEN VALVE

3-WAY VALVE

Fig. 11 — Subcooling Mode (Reheat 1) — Humidi-MiZer System — 48/50HC 04-12

Fig. 12 — Subcooling Mode (Reheat1) — Humidi-MiZer

System 48/50HC 14-28

COMP

LIOC REZIM-IDIMUHLIOC DNOC

EVAP COIL

INDOOR ENTERING

AIR

METERING DEVICE

RLV.x

RDV.x

OUTDOOR AIR

CLOSED VALVE

OPEN VALVE

CLV.x

COMP

Fig. 13 — Hot Gas Reheat Mode (Reheat2) — Humidi-MiZer

48/50HC 04-12

RDV.x

LDV.x

OUTDOOR AIR

System

LIOC REZIM-IDIMUHLIOC DNOC

CLOSED VALVE

OPEN VALVE

3-WAY VALVE

Fig. 14 — Hot Gas Reheat Mode (Reheat2) — Humidi-MiZer System

48/50HC 14-28

METERING DEVICE

EVAP COIL

INDOOR ENTERING

AIR

REHEAT CONTROL The cooling staging and compressor control routines are re-

sponsible for controlling each circuit in one of the three submodes (Cool, Reheat1, or Reheat2). When there is only a cooling demand, one or more circuits will operate in normal cooling mode. When there is only dehumidification demand, all circuits will operate in Reheat2 mode. When there is both cooling demand and dehumidification demand, all circuits will operate in either Reheat1 or Reheat2 mode, with the portion of Reheat1 circuits determined from the cooling demand. The Requested Reheat2 Stages (Operating Modes HMZRREQ.R) shows the control’s request for reheat circuits if cooling is not already requesting all stages. Available Reheat2 Stages (Operating Modes AVL.R) displays circuits that are available for reheat use. Actual Reheat2 Stages (Operating Modes ACT.R) displays the current number of circuits running in Reheat2 mode. These three status points should only be monitored when there is only a dehumidification demand, because their values can be forfeited to cooling stages when cooling demand is present. Reheat2 Stage Incr. Time (Configura-

tion



HMZRR.INC) and Reheat2 Stage Decr. Time (Con-

figuration

or subtracting a compressor for a reheat function. These only apply when using adaptive thermostat or space sensor control. There are three relay outputs that show reheat status. Cool Reheat1 Control (Outputs has switch from pure cooling to reheat ready (based on a dehumidification demand). Reheat2 Valve A (Out-

puts puts

Reheat2 valve is energized. A circuit can be restricted from Reheat2 operation by the out-

side temperature and saturated suction temperature. Reheat2 OAT Limit A (Configuration OAT Limit B (Configuration est outside temperature the respected circuit is allowed to run in reheat2 mode. The lockout on/off status is shown as Reheat2 OAT Lockout A (Operating Modes

R.LO.A) and Reheat2 OAT Lockout B (Operating ModesCOOLHMZRR.LO.B) for their respective cir-

cuit. If a circuit’s saturated suction pressure falls below the low limit configuration during Reheat2 operation, the circuit will switch to reheat1 (the circuits Reheat2 valve will be turned off) for at least 2 minutes and until its suction rises back above the high limit. Reheat2 SSP Lo Limit A (Configura-

tion uration

heat2 mode for individual circuits. Reheat2 SSP Hi Limit A (Configuration B (Configuration limit for Reheat2 mode for each circuit.

REHEAT MODE DIAGNOSTIC HELP The status of reheat mode sensor inputs may be viewed within

the display Inputs menu. The status of reheat mode outputs may be viewed within the display Outputs or Run Sta-

tus

tus of circuit reheat temperature limit lockouts may be viewed within the Humidi-MiZer sub-menu of the cooling mode diagnostic table at Operating Modes

The Service Test mode may be used to force the system to operate in various stages of Reheat1 or Reheat2 mode, or to independently operate the reheat valve control outputs.

The following forced operating states are changed or added to the available service test operation for a Humidi-MiZer equipped unit:

Service Test

A value of On will turn on circuit A in Normal Cooling mode.



HMZRR.DEC) set the time delay when adding



COOLCRC) shows when the unit



COOLRH2.A) and Reheat2 Valve B (Out-



COOLRH2.B) display when the respective circuit’s



HMZRRA.LO) and Reheat2



HMZRRB.LO) set the low-



HMZRRA.LP) and Reheat2 SSP Lo Limit B (Config-



HMZRRB.LP) set the low pressure limit for Re-



HMZRRA.HP) and Reheat2 SSP Hi Limit



HMZRRB.HP) set the high pressure



COOL menus. Additional diagnostic help, including sta-



COOLCMP.A (Cool A Test)



COOLHMZR.



COOL

COOLHMZR



Service Test

A value of On will turn on circuits A and B in Normal Cooling mode.

Service Test

A value of On will turn on circuit A in Reheat1 mode.

Service Test

A value of On will turn on circuits A and B in Reheat1 mode.

Service Test

A value of On will turn on circuit A in Reheat2 mode.

Service Test

A value of On will turn on circuits A and B in Reheat2 mode.

Service Test

For 48/50HC04-12 units, a value of On will turn on the CRC relay. This will turn on CLV.x valves and turn off RLV.x valves.

For 48/50HC14-28 units, a value of On will turn on the CRC relay. This will energize the LDV.x valves.

Service Test A value of On will turn on the RDV.A valve. Service Test A value of On will turn on the RDV.B valve.

COOLCMP.B (Cool B Test)



HMZRRH1.A (Reheat1 A Test)



HMZRRH1.B (Reheat1 B Test)



HMZRRH2.A (Reheat2 A Test)



HMZRRH2.B (Reheat2 B Test)



HMZRCRC (Cool-Reheat1 Valve Test)



HMZRRHV.A (Reheat2 Valve A Test)



HMZRRHV.B (Reheat2 Valve B Test)

Temperature Compensated Start

This logic is used when the unit is in the unoccupied state. The control will calculate early Start Bias time based on Space Temperature deviation from the occupied cooling and heating set points. This will allow the control to start the unit so that the space is at conditioned levels when the occupied period starts. This is required for ASHRAE 90.1 compliance. A space sensor is required for non-linkage applications.

SETTING UP THE SYSTEM The settings for temperature compensated start can be found in

the local display under Configuration

ITEM EXPANSION RANGE UNITS CCN POINT TCS.C Temp.Cmp.Strt.Cool Factr 0 - 60 min TCSTCOOL TCS.H Temp.Cmp.Strt.Heat Factr 0 - 60 min TCSTHEAT

Temp Comp Strt Cool Factr (TCS.C)

This is the factor for the start time bias equation for cooling.

Temp Comp Strt Heat Factr (TCS.H)

This is the factor for the start time bias equation for heating. NOTE: Temperature compensated start is disabled when these

factors are set to 0. TEMPERATURE COMPENSATED START LOGIC

The following conditions must be met for the algorithm to run:

• Unit is in unoccupied state.

• Next occupied time is valid.

• Current time of day is valid.

• Valid space temperature reading is available (sensor or

CCN network).

The algorithm will calculate a Start Bias time in minutes using the following equations:

If (space temperature > occupied cooling set point) Start Bias Time = (space temperature – occupied cooling set

point)* TCS.C If (space temperature < occupied heating set point) Start Bias Time = (occupied heating set point – space tempera-

ture)*TCS.H When the Start Bias Time is greater than zero the algorithm

will subtract it from the next occupied time to calculate the



UNIT.

new start time. When the new start time is reached, the Temperature Compensated Start mode is set, the fan is started and the unit controlled as in an occupied state. Once set, Temperature Compensated mode will stay on until the unit goes into the Occupied mode. The Start Bias Time will be written into the CCN Linkage Equipment Table if the unit is controlled in DAV mode. If the Unoccupied Economizer Free Cool mode is active when temperature compensated start begins, the Unoccupied Free Cool mode will be stopped.

NOTE: The maximum minutes Start Bias can be is 180.

Carrier Comfort Network® (CCN) Configuration

It is possible to configure the ComfortLink control to participate as an element of the Carrier Comfort Network (CCN) system directly from the local display. This section will deal with explaining the various programmable options which are found under the CCN sub-menu in the Configuration mode.

The major configurations for CCN programming are located in the local displays at Configuration

CCN Address (CCN.A)

This configuration is the CCN address the rooftop is assigned.

CCN Address (CCN.B)

This configuration is the CCN bus the rooftop is assigned.

CCN Baud Rate (BAUD)

This configuration is the CCN baud rate.

CCN Time/Date Broadcast (BROD

If this configuration is set to ON, the control will periodically send the time and date out onto the CCN bus once a minute. If this device is on a CCN network then it will be important to make sure that only one device on the bus has this configuration set to ON. If more than one time broadcaster is present, problems with the time will occur.

NOTE: Only the time and date broadcaster can perform daylight savings time adjustments. Even if the rooftop is stand alone, the user may want to set this to ON to accomplish the daylight/savings function.

CCN OAT Broadcast (BROD

If this configuration is set to ON, the control will periodically broadcast its outside-air temperature at a rate of once every 30 minutes.

Global Schedule Broadcast (BROD

If this configuration is set to ON and the schedule number (SCH.N) is between 65 and 99, then the control will broadcast the internal time schedule once every 2 minutes.

CCN Broadcast Acknowledger (BROD

If this configuration is set to ON, then when any broadcasting is done on the bus, this device will respond to and acknowledge. Only one device per bus can be configured for this option.

Schedule Number (SCH.O

This configuration determines what schedule the control may follow.

SCH.N = 0

The control is always occupied.

SCH.N = 1

The control follows its internal time schedules. The user may enter any number between 1 and 64 but it will be overwritten to “1” by the control as it only has one internal schedule.

SCH.N = 65-99

The control is either set up to receive to a broadcasted time schedule set to this number or the control is set up to broadcast its internal time schedule (B.GS) to the network and this is the global schedule number it is broadcasting. If this is the case, then the control still follows its internal time schedules.



B.OAT)

SCH.N)

CCN. See Appendix A.

B.TIM)



B.GS)



B.ACK)

Accept Global Holidays? (SCH.O

If a device is broadcasting the time on the bus, it is possible to accept the time yet not accept the global holiday from the broadcast message.

Override Time Limit (SCH.O

This configuration allows the user to decide how long an override occurs when it is initiated. The override may be configured from 1 to 4 hours. If the time is set to 0, the override function will become disabled.

Timed Override Hours (SCH.O

This displays the current number of hours left in an override. It is possible to cancel an override in progress by writing “0” to this variable, thereby removing the override time left.

SPT Override Enabled? (SCH.O

If a space sensor is present, then it is possible to override an unoccupied period by pushing the override button on the T55 or T56 sensor. This option allows the user to disable this function by setting this configuration to NO.



OV.TL)



HOL.G)

OV.EX)

OV.SP)

Demand Limit

Demand Limit Control may override the cooling algorithm to limit or reduce cooling capacity during run time. The term Demand Limit Control refers to the restriction of machine capacity to control the amount of power that a machine will use. This can save the owner money by limiting peaks in the power supply. Demand limit control is intended to interface with an external network system. This is through a CCN Loadshed POC Device or writing to network points.

To limit stages through network writes, the points Run Sta-

tus



COOLMAX.C and Run StatusHEATMAX.H are

forced on the network through CCN points MAXCSTGS and MAXHSTGS respectively. Force these to the desired maximum stages of cooling/dehumidification and heating, respectively.When there is no force on these points, they automatically reset to allow all cooling/dehumidification and heating stages to be used. These points are reset at power-on/reset (POR).

When using the Loadshed POC to do Demand Limiting, the cool and heat stage limits under both Redline and Loadshed conditions can be set individually with configuration decisions. If the active stages is greater then the loadshed or redline configurations when a loadshed or redline command is given, the unit will remove stages.

Configuration

This is the Loadshed Group Number and corresponds to the loadshed supervisory devices that resides elsewhere on the CCN network and broadcasts loadshed and redline commands to its associated equipment parts. This variable will default to zero which is an invalid group number. This allows the loadshed function to be disabled until configured.

Configuration

This configuration tells the unit the maximum cooling stages allowed to be on during a redline condition.

Configuration

This configuration tells the unit the maximum cooling stages allowed to be on during a loadshed condition.

Configuration

This configuration tells the unit the maximum heating stages allowed to be on during a redline condition.

Configuration

This configuration tells the unit the maximum heating stages allowed to be on during a loadshed condition.

The two Demand Limiting methods can be active simultaneously. The lowest cool and heat stage limits imposed by either method are applied, and these “effective stage limits” are shown in the points CSTGLIMT (Run Status HSTGLIMT (Run Status



CCNLDSHS.GRP



CCNLDSHR.MXC



CCNLDSHS.MXC



CCNLDSHR.MXH



CCNLDSHS.MXH



HEATLMT.H), respectively. In



COOLLMT.C) and

normal running mode, these limits will prevent stages from being added, or stages to be removed, as applicable. In test mode, these limits are ignored, and the user may continue to operate all stages. The point MODEDMDL (Run Status MODED.LMT) is used to show if any Demand Limiting is in effect that prevents the unit from operating either cooling or heating at full-capacity.

NOTE: MODEDMDL may reflect that staging is NOT limited even though Loadshed is active, or the network points are being forced, if the stage limits in effect are not less than the stages present in the unit.

If a more drastic mode of Demand Limiting is required, the network point HVACDOWN (Run Status can be used to prohibit the unit from selecting any HVAC mode, thus preventing the operation of the supply fan, compressors, condenser fans, and heat stages. This point must also be forced, and is reset automatically when not forced, and at POR.

NOTE: HVACDOWN can be used as an immediate shutdown of the unit before limiting capacity (ex. Generator switching).



MODEHV.DN)



Linkage

ComfortLink controls do not require any configuration settings to establish linkage with a Linkage Coordinator. This is done automatically when the unit’s bus and element address are configured in the Linkage Coordinator’s LINKAGE configuration table. The linkage information that is supplied to the Com- fortLink unit by the Linkage Coordinator is as follows:

• Reference zone temperature

• Reference zone occupied biased heating and cooling set points

• Reference zone unoccupied heating and cooling set points

• Composite occupancy mode

The unit will control the equipment based on this information and in return will provide the Linkage Coordinator with the following data:

• Operating mode - Cooling, Heating, Free Cooling, Fire Shutdown Evacuation, or Off

• Supply-air temperature

• Optimal Start Bias time (Based on worst case zone)

This synchronization of data optimizes the efficiency of the unit and the zones to operate at peak system performance at all times. This information can be seen in linkage maintenance tables of the Linkage Coordinator and the RTU; it is updated at approximately 1-minute intervals.

Cooling and heating operation is slightly modified during Linkage control. A PID loop is run to calculate required stages. This is necessary because in stand alone operation, the unit tries to anticipate the space. With Linkage, the unit must try to satisfy the demand as soon as possible. The PID configurations are in Configuration ed and the default values should NOT BE CHANGED.

For information on set up and configuration, see the Space Temperature Control-CCN Linkage text in the Controls Quick Start section of this book.

For additional information on the Linkage Coordinator or Zone Controllers, please refer to their appropriate manuals.



PID. These values have been field test-

Alarm Handling

There are a variety of different alerts and alarms in the system. Alerts are indicated by TXXX (where XXX is the alert number) on the display and generally signify that the improperly functioning circuit can restart without human interaction. If an alarm occurs, indicated by AXXX (where XXX is the alarm number), the damaged circuit will generally not restart without an alarm reset via the scrolling marquee display or CCN.

The response of the control system to various alerts and alarms depends on the seriousness of the particular alert or alarm. In the mildest case, an alert does not affect the operation of the unit in any manner. An alert can also cause a “strike.” A “striking” alert will cause the circuit to shut down for 15 minutes. This feature reduces the likelihood of false alarms causing a properly working system to be shut down incorrectly. If three strikes occur before the circuit has an opportunity to show that it can function properly, the circuit will strike out, causing the shutdown alarm for that particular circuit. Once activated, the shutdown alarm can only be cleared via an alarm reset.

However, circuits with strikes will be given an opportunity to reset their strike counter to zero. As discussed above, a strike typically causes the circuit to shut down. Fifteen minutes later, that circuit will once again be allowed to run. If the circuit is able to run for 1 minute, its replacement circuit will be allowed to shut down (if not required to run to satisfy requested stages). However, the “troubled” circuit must run continuously for a user defined time (Configuration detectable problems before the strike counter will be reset to zero. Default value is 5 minutes.

CCN ALARM BROADCAST Operators of CCN networks might not want to be notified of

“striking” alerts for refrigerant circuits until the circuit has been shut down due to 3 strikes. Set the cooling configuration of Alert Each Strike (Configuration play, ALM_NOW on CCN) to YES to broadcast each circuit strike alert. Set Alert Each Strike to NO to broadcast only circuit shut down. Alert Each Strike configuration is ignored during Service Test and all alerts are broadcast.

ALARM RELAY OUTPUT The alarm relay output is a normally open 24 vac output be-

tween field connection terminal board terminals C and X. Selection of which alerts and alarms will result in closing of the alarm relay may be set in the Alarm Relay Configuration (Con-

figuration

sult in the alarm output relay, ALRM, status of ON and 24 vac between C and X on the field connection terminal board when that particular condition is in an alarm state. Setting a configuration to NO will result in no action by the alarm output relay for that particular condition.

NOTE: An accessory filter switch can be used along with the alarm relay output function to indicate dirty filter service need.

See the Troubleshooting section for more information on viewing, diagnosing, and clearing alerts and alarms.



ALM.O). Setting a configuration to YES will re-



COOLRST.C) with no



COOLALM.N on dis-

EnergyX® Units

GENERAL An EnergyX unit is a 48/50HC rooftop unit and energy recov-

ery ventilator (ERV). It operates the ERV module in an integrated manner with the base rooftop unit. The base rooftop unit functions per the base unit sequence of operation, for information regarding ComfortLink controller operation see the Com- fortLink Controls, Start-Up, Operations, and Troubleshooting Instructions. The ERV will operate based on communication from the ComfortLink controller. The following section discusses the ERV operation in detail. In summary, the ERV operates to provide pre-conditioned outside air for ventilation requirements. If equipped with an optional economizer the ERV can provide free cooling when the outside air conditions are satisfactory.

In general the ERV monitors occupancy and indoor fan state of the base unit to determine when to activate. The outside air fan(s) bring in the outside air pass it through the enthalpy wheel and into the rooftop mixing box. The building return air is pulled through the enthalpy wheel by the exhaust fan(s) and released outside. During operation the enthalpy wheel is rotating to use the building air to pre-condition the outside air.

When free cooling is desired and allowed the wheel is not needed to pre-condition the air therefore an economizer damper (wheel bypass) is used to bring in the outside air directly to the mixing box.

COMMUNICATION The ERV relies on communication with the ComfortLink

controller to operate. The ERV monitors ComfortLink controller points to determine operation. The ERV writes to points in the ComfortLink controller to provide the user with

Table 11 — Inputs - Points the ERV Reads from ComfortLink Controller

its running status. If communication is lost the ERV will shut down and remain in the Off mode until communication is established. Refer to the troubleshooting section for details on communication failures. Table 11 shows the ComfortLink points that the ERV monitors for operation and a brief description of their functions. Table 12 shows the ComfortLink points that the ERV uses for its configurations and a brief description of each. Table 13 shows the ComfortLink points that the ERV writes to based on its running status.

CCN POINT*

NVO_MODE nvoUnitStatus.mode xxxx Determine what mode RTU is in OCCUPIED OCC Currently Occupied No/Yes Determine if RTU is occupied IDFSTATE Indoor Fan State Off/On Determine if the RTU indoor fan is running FANSPEED F.SPD Commanded Fan Speed xxx % Determine if the RTU indoor fan is running ECONOCMD EC.CP Econo Commanded Position 0 to 100 % Determine if the RTU commands free cooling IAQ IAQ IAQ Level (sensor) xxxx Space CO IAQIN IAQ.S IAQ Level (switch) Low/High Determine if CO SAT SAT Supply Air Temperature xxx.x °F RTU supply air temp OA_TEMP OAT Outdoor Air Temperature xxx.x °F RTU Outdoor Temp SPACE_T SPT Space Temperature xxx.x °F Building Space Air Temp RETURN_T RAT Return Air Temperature xxx.x °F Building Return Air Temp PE_1 PE.1 Power Exhaust 1 Relay Off/On N/A PE_2 PE.2 Power Exhaust 2 Relay Off/On N/A ECONO EC.EN Economizer Installed No/Yes No: no FIOP

IAQANCFG IA.CF IAQ Analog Input Config 0=No IAQ

IAQANFAN IA.FN IAQ Analog Fan Config 0=Never

IAQINCFG II.CF IAQ Switch Input Config 0=No IAQ

IAQINFAN II.FN IAQ Switch Fan Config 0=Never

DAQ_LOW AQD.L AQ Differential Low 0 to 5000 100 Sets indoor/outdoor PPM difference to start

DAQ_HIGH AQD.H AQ Differential High 0 to 5000 700 Sets indoor/outdoor PPM at which max vent

IAQOVPOS OVR.P IAQ Override Position 0 to 100 % 100 Sets OA fan speed during override S_OADMPR OA.DM OAU 2 - position Damper Close/Open Close Test damper while in test mode S_WHEEL WHL OAU Wheel Test 0 to100 % 0 Test wheel while in test mode S_OAFAN OA.OF OAU OA Fan Speed Test 0 to100 % 0 Test intake fan(s) while in test mode S_EXFAN OA.XF OAU PE Fan Speed Test 0 to100 % 0 Test exhaust fan(s) while in test mode S_OAHEAT OA.HT OAU Tempring Heater Test 0 to 100 % 0 Test tempering heater while in test mode

* These can be viewed under a variety of CCN tables with a CCN device. † These can be viewed under a variety of menus on the scrolling marquee or Navigator™ display.

SCROLLING

MARQUEE

POINT†

EXPANDED TEXT RANGE UNITS DEFAULT FUNCTION

2 sensor level (PPM)

2 is high or low

Determine if there is a Economizer damper (wheel Bypass)

Tells if a sensor is installed for DCV or override

high CO

ventilating more

occurs

1=DCV 2=Override IAQ 3=Ctrl Min Pos

1=Occupied 2=Always

1=DCV N/O 2=DCV N/C 3=Override N/O 4=Override N/C

1=Occupied 2=Always

Yes:

FIOP

0: no FIOP 1: FIOP

0 Tells if the ERV can run during unoccupied for

0 Tells if a switch is installed for DCV or override

0 Tells if the ERV can run during unoccupied for

Table 12 — Configurations - ERV Configurations Read from ComfortLink Controller

CCN POINT*

OAU_TYPE OA.TY Outdoor Air Unit Type

OAFANCRV OA.FC Outside Air Fan Curve 0 to 999

PEFANCRV PE.FC Exhaust Air Fan Curve 0 to 999

UNOCCRUN U.RUN

FATALOAU OAU.F Shut Down on Fan Failure No/Yes YES

MODWHEEL M.WHL Modulating Wheel Install No/Yes NO

MINOACFM OA.MN

MINDCVSP DCV.M Min DCV Outside Air CFM 0 to 32000 CFM

PEX_CTL PEX.C Power Exhaust Control

EXOFFSET PE.OF

OAU_BPSP BP.SP Building Pressure Setpnt - 0.25 to 0.25 in H

OATEMPER OA.TM Outside Air Tempering Disable/Enable Disable

OATMPLOC TM.LO

OATMPSPT TM.SP

OACFM_K OAC.K Outside Air CFM k Factor 0.8 to 1.2 1.0

EXCFM_K EXC.K Exhaust Air CFM k Factor 0.8 to 1.2 1.0

EFB_ENBL EFBE ERV Fan Boost Enable No/Yes NO

* These can be viewed under the CCN Table OAU_CFG with a CCN device. †These can be viewed under Configuration → OAU on the scrolling marquee or Navigator™ display.

SCROLLING

MARQUEE

POINT†

EXPANDED TEXT RANGE UNITS DEFAULT FUNCTION

OAU Unoccupied Operation

Minimum Outside Air CFM

Power Exhaust CFM Offset

OA Tempring Lockout Temp

OA Tempring SAT Setpoint

0=No OAU 1=FIOP EXv2

No/Yes NO

0 to 32000 CFM

0=offset CFM 1=BP

- 17000 to 17000 CFM –200

0 to 80 °F 60

35 to 80 °F 55

1: FIOP EXv2

1: 04 2: 05-06 3: 07 4: 08-12 5: 14 6: 17-20 7: 24-28

1: 04, 1ph, and econ 2: 04, 3ph, and econ 3: 04, 1ph, and no econ 4: 04, 3ph, and no econ 5: 05-06 1ph 6: 05-06 3ph 7: 07 8: 08-12 9: 14 10: 17-20 and econ 11: 17-20 and no econ 12: 24-28

375: 04 800: 0506 1000: 07 2500: 08-12 3000: 14 4000: 17-20 5000: 24-28

100: 04 250: 05-06 600: 07 1000: 08-12 1500: 14-24 2000: 24-28

O 0.05 Sets required building pressure

Defines what kind of OAU is installed

Determine what outside air fan curve to use

Determine what exhaust air fan curve to use

Tells OAU to run in unoccupied mode

Tells OAU to shut off if one of its fans fail

Determine if the OAU’s wheel is a modulating one

Sets Design OA CFM for ventilation

Sets absolute minimum OA CFM for ventilation

Determine how to control the exhaust fans

Sets offset CFM setpoint of exhaust based on intake

Determine if there is tempering heater installed

Sets the outside temp and below to allow tempering

Sets target supply air temperature during tempering

Sets outside air curve correction factor

Sets exhaust air curve correction factor

Tells RTU to adjust fan speed for low outside air CFM

Table 13 — Status Points — ERV Writes These Points to ComfortLink Controller

CCN POINT*

OAU_RUN OA.RN OAU System Run State

OAU_MODE OA.OP OAU Operating Mode

UPC_VER UPC UPC Software Version 0 to 9999 Active UPC software version

OAU_VER OAU OA Unit Software Version 0 to 9999 Active EXCB software version

ACTOACFM A.OA Actual Outside Air CFM 0 to 32000 CFM Real Time CFM being brought in

ACTEXCFM A.EX Actual Exhaust Air CFM 0 to 32000 CFM Real Time CFM being exhausted

CMDOACFM C.OA Command Outside Air CFM 0 to 32000 CFM Commanded CFM to bring in

CMDEXCFM C.EX Command Exhaust Air CFM 0 to 32000 CFM Commanded CFM to exhaust

OAU_LAT LAT OAU Leaving Air Temp xxx.x °F Air temperature leaving the ERV (RTU intake)

OAU_EXAT EXAT OAU Exhaust Air Temp xxx.x °F Air Temperature leaving the ERV (exhaust)

OAU_BP BP Building Pressure –0.25 to 0.25 in H

OAUDMPR 2P.DM OAU 2 --- position Damper Close/Open Exhaust damper position status

OAUWHEEL WHL OAU Wheel Speed 0 to100 % Current ERV wheel speed

OAFANSPD OA.FS OAU OA Fan Speed 0 to100 % Current ERV’s intake fan(s) speed

OAUPESPD EX.FS OAU Exhaust Fan Speed 0 to100 % Current ERV’s exhaust fan(s) speed

OAHEATER OA.HT OAU Tempering Heater 0 to 100 % ERV’s SCR heater commanded capacity

OAUALRM1 ALM.1 OAU Motor Failure Alarm Off/On ERV’s motor failure alarm status

OAUALRM2 ALM.2 OAU Dirty Filter Alarm Off/On ERV’s dirty filter alarm status

OAUALRM3 ALM.3 OA Low CFM Alarm Off/On ERV’s low CFM alarm status

OAUALRM4 ALM.4 OAU Alarm Off/On ERV’s General Alarm status

* These can be viewed under Run Status→OAU or Operating Modes→OAU on the scrolling marquee or Navigator™ display. † These can be viewed under the CCN tables OAUDISP or OAU_DIAG with a CCN device.

SCROLLING

MARQUEE POINT†

EXPANDED TEXT RANGE UNITS FUNCTION

1=AUTO 2=OFF 3=TEST

0=Off 1=ERV (DCV) 2=Free Cooling 3=OA Tempering 4=Defrost 5=Test 6=Ext. Mode 1 7=Ext. Mode 2 8=Ext. Mode 3

High level ERV state

ERV’s current operating mode

O Current building pressure

3 to 25 Ton Modulating ERV

YES

Notes:

* Min CFM represents the minimum outside air CFM requirement based on CO

values and setpoints.

** Occupied also means being in the unoccupied period but configured to run.

YES

Is there

frost on the

wheel?

YES

Is unit

occupied**

and IDF on?

YES

ERV Mode = OFF

Wheel = off ERV 2POS Damper = Closed OA CFM = 0 Ex CFM = 0

ERV Mode = Test

User sets ERV to desired values for testing purposes OAU OA Fan Speed Test→OA.OF OAU PE Fan Speed Test→OA.XF OAU 2-position Damper Test→OA.DM OAU Wheel Test→WHL

ERV Mode = Free Cooling

Wheel = stop-jog ERV 2POS Damper = Open OA CFM = Between Min CFM* and 100 dependent on Econ Pos Ex CFM = OA CFM - Ex CFM offset

ERV Mode = Defrost

Wheel = On ERV 2POS Damper = Open OA CFM = 0 Ex CFM = Min CFM* in effect

- Ex CFM offset

ERV Mode = ERV or DCV Mode

Wheel = On ERV 2POS Damper = Open OA CFM = Min CFM* Ex CFM = OA CFM - Ex CFM offset

START

TEST

(RTU in test

mode)

COOL

(RTU in

Cool)

VENT

(RTU in Heat,

or Vent)

Is economizer open>than

5%?

The modulating ERV is an intelligent ERV with variable speed fan motors. The ERV can provide a variety of volumes of outside air and offset it with different exhaust speeds. CO can also be tied into it for demand controlled ventilation

sensors

(DCV) operation. The modulating ERV will operate based on occupancy and the rooftop’s operating mode, the following sections explain operation in detail. Refer to Fig. 15 for the overview flow diagram of a modulating ERV operation.

Fig. 15 — Modulating ERV Control and Operation Flow Chart

OCCUPANCY The ERV will not be allowed to run unless it is determined to

be occupied. The ERV monitors the rooftop’s occupancy point (Run Status pied. The ERV watches the rooftop’s indoor fan state point (CCN Point = IDFSTATE) to know when its indoor fan has started. When the rooftop is occupied and its indoor fan is on, the ERV is considered to be occupied and allowed to run.

The ERV can also operate during the rooftop’s unoccupied period. If the ERV is configured for unoccupied operation (Configu-

rations

building occupancy of the ComfortLink controller and allow occupancy any time the rooftop fan is on. If not configured for unoccupied operation but there is a CO and the ComfortLink controller is configured to turn on its indoor fan for CO

→MODE →OCC) to determine when it is occu-

→OAU →U.RUN = YES), then it will ignore the

sensor or switch installed

2 ventilation at any time (Configuration

→AIR.Q →IA.FN = 2, or Configuration →AIR.Q →II.FN

= 2), the ERV will be occupied any time the CO MODES OF OPERATION

The ERV has 3 basic functions: Auto, Off, or Test. These are defined as System run states and displayed in the OAU run status menu (Run Status ways operate in one of the following operating modes depending upon the ComfortLink controller mode and outside conditions: Off, ERV (DCV) Free Cooling, OA Tempering, Defrost, or Test. The ERV monitors the ComfortLink CCN point NVO_MODE to determine the rooftops operating mode. The NVO_MODE values tell the ERV what the rooftop operating mode is in a numeric form. The ERV’s operating mode is displayed numerically as OAU Operating Mode (Run Status

→OAU →OA.RN). The ERV will al-

needs the fan.

→OAU →OA.OP). These modes and their corresponding

numbers are described below.

Off Mode (OA.OP = 0)

The ERV will be set to the Off mode whenever the rooftop indoor fan is turned off, ERV is unoccupied, NVO_MODE equals 6, or if communication fails. During Off Mode, the ERV 2 position dampers will be closed and the wheel, outside air fans(s), and exhaust fan(s) will be off.

Test Mode (OA.OP = 5)

If at any time during operation, the rooftop is put in Service Test mode (NVO_MODE equals 7) the ERV will be set to Test Mode. Refer to Start-Up section for Test mode operation.

Free Cooling Mode (OA.OP = 2)

Free Cooling Mode is only available if an optional economizer damper is factory-installed in the ERV (Configuration

→ECON →EC.EN = Yes). Free Cooling Mode will be active

when the rooftop unit is in Unoccupied Free Cooling Mode, Free Cooling Mode, or in Cooling Mode and the economizer damper position (Outputs 5% (NVO_MODE = 10 or 3). ERV occupancy tells the control which speed to start the outside air fan(s) during free cooling, because the outside fan(s) are needed to assist the indoor fan in bringing in outside air.

When in Free Cooling Mode, the ERV’s 2-position damper will be open and the wheel will be set to stop/jog operation. The rooftop unit will modulate the economizer damper to provide free cooling as if an ERV was not installed. As the economizer damper opens the ERV outside air fan(s) will maintain a speed that produces minimum outside air CFM. Once the economizer damper position passes that percent fan speed of the outside air fan(s), the fan(s) speed will ramp up directly with the economizer damper position, up to 100%. The exhaust fan(s) will run at a speed equal to the required offset CFM. Refer to Exhaust Control for details on determining offset CFM.

→ECON →EC.CP) is greater than

IMPORTANT: Refer to the base unit Controls, Start Up, operation, and Troubleshooting manual for details on how the rooftop unit modulates the economizer damper for free cooling.

Defrost Mode (OA.OP = 4)

Defrost Mode is only available when the optional Frost Protection is factory-installed in the ERV. The ERV will be set to defrost mode any time the ERV wheel is running and frost is detected on the wheel. The EXCB D14 LED will turn on to indicate the frost switch is active. Defrost Mode runs for at least 2 minutes but continues to run until the frost is removed. The frost protection device senses a pressure differential across the wheel and trips when that differential is greater than the setpoint (default 2.0 in wg). For information on the frost protection device, refer to the Major Component section.

When in Defrost Mode, the ERV 2 position damper will be open and the wheel will be rotating. The outside air fan(s) will ramp down to 0% speed (shut-off). The exhaust fan(s) will run at a speed equal to the required offset CFM. Refer to Exhaust Control for details on determining offset CFM.

ERV (DCV) Mode (OA.OP = 1)

General ERV Mode ERV Mode is the basic operating mode of the ERV. With no

options installed on the ERV this will be the only operating mode besides off and test. ERV Mode will be active when the rooftop ComfortLink controller mode is Heating, Cooling, Fan Only, or Dehumidification (NVO_MODE = 1, 3, 9, or 14) and the ERV is occupied.

When in ERV mode, the ERV 2 position damper will be open and the wheel will be rotating. The outside air fan(s) will run at a speed that produces a CFM equal to the minimum outside air CFM setpoint (Configuration haust fan(s) will run at a speed equal to the required offset CFM. Refer to Exhaust Control for details on determining offset CFM.

ERV Mode with DCV If an optional economizer is factory-installed in the ERV (Con-

figuration sensor or switch is installed (Configuration →AIR.Q

→ECON →EC.EN = Yes) and an optional CO

→OAU →OA.MN). The ex-

→IA.CF = 1 or 2) or (Configuration →AIR.Q →II.CF = 1

or 2), DCV ERV Mode will be active when the rooftop Com- fortLink controller mode is Heating, Cooling, Fan Only, or De-

humidification (NVO_MODE = 1, 3, 9, or 14) and the ERV is occupied.

When in DCV ERV mode, the ERV 2 position damper will be open and the wheel will be rotating. The outside air fan(s) will run at a speed that produces a CFM equal to the minimum outside air CFM determined by Demand Controlled Ventilation (DCV). The exhaust fan(s) will run at a speed equal to the required offset CFM. Refer to Exhaust Control for details on determining offset CFM.

Sensor Demand Controlled Ventilation (DCV) uses the indoor air quality levels (CO is required for ventilation. The ERV monitors the IAQ (Inputs

→AIR.Q →IAQ) reading from the rooftop’s installed CO

sor and compares it to a hard coded outside air value of 400PPM. The difference is then weighed on scale between AQ Differential Low (Configuration High (Configuration minimum outside air CFM required for ventilation. The minimum outside air CFM can be equal to or between the Min DCV outside air CFM (Configuration and the minimum outside air CFM (Configuration

→OA.MN) setpoint. As the CO

to AQD.H, the ERV outside air CFM requirement will rise from DCV.M to OA.MN. The outside air fan(s) will ramp its speed %

PPM) to determine how much outside air

sen-

→AIR.Q →AQD.L) and AQ Differential

→AIR.Q →AQD.H) to determine the

→OAU →DCV.M) setpoint

→OAU

differential rises from AQD.L

VENTILATION FOR PEOPLE

VENTILATION FOR SOURCES

INCREASING VENTILATION

ECON MIN

AT M AX

FANSPEED

POSITION

(MP.MX)

MINIMUM

IAQ

DAMPER

POSITION

(AQ.MN)

OC EDISTUO/EDISNI007001

DIFFERENTIAL

AQ DIFFERENTIAL LOW (AQD.L)

AQ DIFFERENTIAL HIGH (AQD.H)

up or down to produce the required CFM. If at any time the CO sensor fails or IAQ reads 0ppm, the DCV minimum outside air requirement will be forced to the maximum value (OA.MN). Fig. 16 shows the DCV minimum outside air CFM determination curve.

Fig. 16 — IAQ DCV Control

Switch Demand Controlled Ventilation (DCV) uses the indoor air quality levels (High/Low) to determine how much outside air is required for ventilation. The ERV monitors the IAQ switch (Inputs installed CO

→AIR.Q →IAQ.S) reading from the rooftop’s

switch. The minimum outside air CFM will be

equal to one of the following: Min DCV outside air CFM (Configuration outside air CFM (Configuration point. If the CO

→OAU →DCV.M) setpoint, or the minimum

→OAU →OA.MN) set-

switch reads low the outside air CFM require-

ment will be DCV.M. If the switch reads high the outside air CFM requirement will be OA.MN. The outside air fan(s) will ramp its speed % up or down to produce the required CFM.

OA Tempering Mode (OA.OP = 3)

OA Tempering Mode is only available when the optional electric heater is field-installed in the ERV and enabled (Configu-

ration

→OAU →OA.TM = Enable). The ERV can only be

set to OA Tempering mode when the ERV is occupied and the rooftop is not running cooling or heating. The rooftop must be in Ventilation (Fan-Only) mode (NVO_MODE = 9) and the outside air temperature (Inputs

→AIR.T →OAT) must be

less than the OA Tempering Lockout Temp (Configuration

→OAU →TM.LO) to allow the ERV to run OA Tempering

Mode. The electric heater will then be turned on and modulated 0 to 100% based on the supply air temperature (Inputs

→AIR.T →SAT) relative to the OA Tempering SAT setpoint

(Configuration When in OA Tempering Mode, the ERV runs as standard ERV

(DCV) mode: 2 position damper will be open and the wheel will be rotating. The outside air fan(s) will ramp to maintain correct outside air CFM. The exhaust fan(s) will ramp for the required offset CFM. Additionally the ERV’s Electric Heater will ramp up 1% every 2 seconds and ramp down 2% every 1 second based on how far the SAT is away from the setpoint. If the SAT equals the setpoint then the electric heater will remain at current percentage.

EXHAUST CONTROL When the Power Exhaust control is set of Offset CFM (Config-

uration

→OAU →PEX.C = 0), the ERV exhaust fan(s) oper-

ate to offset the outside air being introduced to the building. The required exhaust offset CFM is determined based on the

→OAU →TM.SP).

exhaust offset setpoint (Configuration

→OAU →PE.OF).

The exhaust offset setpoint can be set as a negative or positive number to accommodate a requirement of positive or negative building pressure. A positive setpoint will produce a negative building pressure. A negative setpoint will produce a positive building pressure.

The ERV will determine the required amount of outside air CFM based on setpoints and current mode of operation. The commanded exhaust air CFM (Run Status

→OAU →C.EX)

is then calculated by the sum of the actual outside air CFM (Run Status

→OAU →A.OA) and the exhaust air offset set-

point (PE.OF). During defrost mode the exhaust will run the same as if the outside air fan(s) were still running.

When the Power Exhaust Control is set for Building pressure control (Configuration

→OAU →PEX.C = 1), the ERV ex-

haust fan(s) operate to maintain a building pressure. A building pressure transducer must be purchased separately and properly field-installed in the ERV. A desired building pressure is set as Building Pressure Setpoint (Configuration

→BP.SP). The actual building pressure (Run Status →OAU →BP) is compared to the setpoint (BP.SP). The exhaust fan

will then be ramped up and down at the rate of 1% every 2 seconds to try and maintain the desired building pressure. The exhaust fan(s) will slow to increase the building pressure and speed up to decrease the building pressure.

WHEEL STOP/JOG During free cooling the wheel utilizes a “stop-jog” operation to

periodically rotate the wheel and minimize potential dirt buildup and excess wear on one section of the wheel. The wheel will rotate for 5 seconds then stop for 5 minutes.

STATUS POINTS The ERV updates points within the ComfortLink controller to

represent its running status. These points are shown in Table 13 and can be viewed on the scrolling marquee or handheld Navigator™ display under the run status outside air menu (Run Status

→OAU). These points include but not limited to: commanded

and actual outside air CFM, commanded and actual exhaust air CFM, ERV outputs, software versions, and internal ERV air temperatures.

TROUBLESHOOTING

The scrolling marquee display shows the actual operating conditions of the unit while it is running. If there are alarms or there have been alarms, they will be displayed in either the current alarm list or the history alarm list. (See Table 14.) The Service Test mode allows proper operation of the compressors, fans, and other components to be checked while the unit is not operating. See Service Test.

Complete Unit Stoppage

There are several conditions that can cause the unit not to provide heating or cooling:

• If an alarm is active which causes the unit to shut down, diagnose the problem using the information provided in Alarms and Alerts section below.

• Cooling and heating loads are satisfied.

• Programmed occupancy schedule.

• General power failure.

• Tripped 24-volt transformer circuit breakers.

• Blown fuse or circuit breakers

• Unit is turned off through the CCN network.

• If supply-air temperature is less than the Minimum SAT Lower Level (SAT.L) configuration value, unit cannot cool.

→OAU

• If outdoor-air temperature is less than the Compressor Lockout Temperature (CA.LO, CB.LO) configuration val- ue, unit ca not cool.

• If outdoor-air temperature is greater than the Heating Lockout Temperature (HT.LO) configuration value, unit cannot heat.

Restart Procedure

Before attempting to restart the machine, check the alarm list to determine the cause of the shut down. If the shutdown alarm for a particular control function has occurred, determine and correct the cause before allowing the unit to run under its own control again. When there is problem, the unit should be diagnosed in Service Test mode. The alarms must be reset before the control function can operate in either Normal mode or Service Test mode.

Alarms and Alerts

VIEWING AND CLEARING UNIT ALARMS Presence of active alarms will be indicated on the scrolling

marquee display by the Alarm Status light turning on and by the number of active alarms being displayed in the automatic View of Run Status. Presence of active alarms may also be signaled on the Alarm Output terminals. Each alarm may also be broadcast on the CCN network. Active alarms and past alarm history can be reviewed and cleared via the local display or a CCN device. The following menu locations are used for the local display:

Alarms



R.CURR (Reset All Current Alarms)

Change to YES to reset all active alarms. Turning unit power off will also reset all current alarms.

Alarms



R.HIST (Reset Alarm History)

Change to YES to reset the alarm history. Turning unit power off will not reset the alarm history.

Alarms



CURR (Currently Active Alarms)

Use the ENTER key, then scroll through any alarm numbers using the up and down arrow keys. Alarms are displayed in numerical order.

Alarms



HIST (Alarm History)

Use the ENTER key, then scroll through any alarm numbers using the up and down arrow keys. Up to 20 alarms are displayed in order of occurrence, with time and date.

The description for an alarm can be viewed on the scrolling marquee display by pressing ESCAPE and ENTER keys simultaneously while displaying the alarm code number. Be sure to expand description for each code, because in some cases there are different possible descriptions and causes for the same code number.

DIAGNOSTIC ALARM CODES AND POSSIBLE CAUSES

Alert Codes T051 and T055 (without Current Sensors)

These alerts can only be activated if set to Diagnose Compressor Safety (Configuration different texts for each alert code. There are two different alerts which have corresponding test mode alerts indicated with “Service Test” in the expanded text. Pressing enter and esc on the scrolling marquee or Navigator display to expand the T051 and T055 alert will show you one of the below alerts. Make sure the expanded text is read correctly before troubleshooting. Alert codes T051 and T055 are for compressors A1 and B1 respectively.

• Compressor Safety Trip

These alerts occur when the respective compressor has been running for 25 sec and the Saturated Suction Pressure (Pres-

sures



tion. A change in compressor operation is when the SSP changes more than the Maximum Suction Change configuration

SSP.A or SSP.B) reflects a change in compressor opera-



COOLD.CMP = Yes). There are 4



(Configuration window while running the compressor and persists for 40 seconds. This alert can also occur when the respective compressor is diagnosed with a high pressure switch trip. A high pressure trip is when the compressor suction rises and falls two times within 2 minutes.

When this occurs, the control turns off the compressor and logs a strike for the respective circuit. These alerts reset automatically. The possible causes are: high-pressure switch (HPS) open, Condensate overflow switch (COFS) open, compressor internal protection is open, or a wiring error (a wiring error might not allow the compressor to start). The HPS and optional COFS are wired in series with compressor relays on the MBB. If one of these opens during compressor operation, the compressor stops causing the control to activate this alert.

• Compressor Detected After Turnoff

These alerts occur when the respective compressor is turned off but the Saturated Suction Pressure (Pressures SSP.B) does not reflect a shutdown. When shutting down a compressor suction pressure must rise more than Maximum Suction Change configuration (Configuration MX.SA or MX.SB) within the first 10 seconds and stay above it. When this occurs, the control turns off all of the compressor relays, stays in cooling mode and keeps the indoor fan on. Use the scrolling marquee to reset the alert. The possible causes are a welded contactor, frozen compressor relay on MBB, or adverse conditions.

Alert Codes T051 and T055 (with Current Sensors)

These alerts can only be activated if Current Sensing A1 or B1 is enabled (Configuration abled). There are 4 different texts for each alert code. There are two different alerts which have corresponding test mode alerts indicated with “Service Test” in the expanded text. Pressing enter and esc on the scrolling marquee or Navigator display to expand the T051 and T055 alert will show you one of the below alerts. Make sure the expanded text is read correctly before troubleshooting. Alert codes T051 and T055 for compressors A1 and B1 respectively.

• Compressor Safety Trip

These alerts occur when the Current Sensor (CS) does not detect compressor current during compressor operation. When this occurs, the control turns off the compressor and logs a strike for the respective circuit. These alerts reset automatically. The possible causes are: high-pressure switch (HPS) open, Condensate overflow switch (COFS) open, compressor internal protection is open, or a wiring error (a wiring error might not allow the compressor to start). The HPS and optional COFS are wired in series with compressor relays on the MBB. If one of these opens during compressor operation, the compressor stops causing the control to activate this alert.

• Compressor Detected After Turnoff

These alerts occur when the Current Sensor (CS) detects current when the compressor should be off. When this occurs, the control turns off all of the compressor relays, stays in cooling mode and keeps the indoor fan on. Use the scrolling marquee to reset the alert. The possible causes are a welded contactor, frozen compressor relay on MBB, or adverse conditions.

Alert Codes T064 and T065 — Circuit Saturated Condensing Temp Thermistor Failure

Alert codes T064 and T065 are for circuits A and B respectively. These alerts occur when the temperature is outside the range –40 to 240°F (–40 to 116°C). The cause of the alert is usually a faulty thermistor, a shorted or open thermistor caused by a wiring error, or a loose connection.

Alert Code T066 and T067 — Circuit Saturated Suction Temperature Thermistor Failure

Alert codes T066 and T067 are for circuits A and B respectively. These alerts occur when the unit’s suction transducers are

COOLMX.SA or MX.SB) in a two second



SSP.A or



COOL



COOLCS.A1 or CS.B1 = En-

turned off internally. Cooling will not operate. This is usually due to a network force on a non exposed CCN point. Reload factory defaults or reinstall software on the MBB. Consult the network manager if alert continues.

Alert Code T073 — Outdoor Air Temperature Thermistor Failure

This alert occurs when the temperature is outside the range –40 to 240°F (–40 to 116°C). For all units, all ambient temperature lockout limits for cooling and heating are ignored. For economizer equipped units, the economizer will not operate to provide cooling. The economizer will still operate for ventilation. This alert resets automatically. The cause of the alert is usually a faulty thermistor, a shorted or open thermistor caused by a wiring error, or a loose connection.

Alert Code T074 — Space Temperature Thermistor Failure

This alert occurs when the temperature is outside the range –40 to 240°F (–40 to 116°C). This alert will only occur if the unit control type is configured for Space Sensor (versus Thermostat). Cooling and heating will not operate. For economizer equipped units, the economizer will still operate for ventilation. This alert resets automatically. The cause of the alert is usually a faulty thermistor in the T-55, T-56, or T-58 device, a shorted or open thermistor caused by a wiring error, or a loose connection.

Alert Code T075 — Supply Air Temperature Thermistor Failure

This alert occurs when the temperature is outside the range –40 to 240°F (–40 to 116°C). Economizer cooling and adaptive compressor staging cannot occur while this alarm is active. This alert resets automatically. The cause of the alert is usually a faulty thermistor, a shorted or open thermistor caused by a wiring error, or a loose connection.

Alert Code T076 — Return Air Thermistor Failure

This alert occurs when the temperature is outside the range –40 to 240°F (–40 to 116°C). This alert will only occur if the unit is configured for a return air sensor. Economizer differential dry bulb control will not be allowed during this alert. This alert resets automatically. The cause of the alert is usually a faulty thermistor, a shorted or open thermistor caused by a wiring error, or a loose connection.

Alert Code T077 — Space Relative Humidity Sensor Failure

This alert occurs when the input is less than 3.5 mA and the sensor is configured as installed. If a humidistat is not installed, then dehumidification will not be functional. Check sensor and wiring. This alert clears automatically.

NOTE: An ECB must be installed to use the space relative humidity sensor.

Alert Codes T092 and T093 — Circuit Suction Pressure Transducer Failure

Alert codes T092 and T093 are for circuits A and B respectively. These alerts occur when the board does not properly read the transducer voltage. A circuit cannot run when this alert is active. Use the scrolling marquee to reset the alarm. The cause of the alert is usually a faulty transducer, faulty 5-v power supply, or a loose connection.

Alert Codes T102 and T103 — Compressor Current Sensor Failure

Alert codes T102 and T103 are for compressors A1 and B1, respectively. These alerts can only occur if the unit is configured to have compressor current sensors (Configura-

tion



COOLCIR.ACS.A1 or CS.B1). These are not factory

installed so would have to be installed in the field and configured accordingly. These alerts occur when the output of the current sensor (CS) is a constant high value. These alerts reset automatically. The cause of the alert is a wiring error, a loose connection, or when configured to have the sensors when they are not actually installed. If the problem cannot be resolved and the CS board

must be replaced, the CS board can be disabled while securing a replaced board. A CS board is disabled by setting the corresponding configuration to DISABLE.

Alert Codes T110 and T111 — Circuit Loss of Charge

Alert codes T110 and T111 are for circuits A and B respectively. These alerts have “Service Test” text that will be displayed if the alert occurred during service test. These alerts occur when the compressor is OFF and the suction pressure is less than 5 psig and OAT is greater than –5°F for 1 continuous minute. Use the scrolling marquee to reset the alert. The cause of the alert is usually low refrigerant pressure or a faulty suction pressure. These alerts only occur when the compressor is OFF because the low refrigerant pressure alarms (alerts T133 and T134) handle this situation when the compressor is operating.

Alert Codes T126 and T127 — Circuit High Discharge Pressure

Alert codes T126 and T127 are for circuits A and B respectively. These alerts have “Service Test” text that will be displayed if the alert occurred during service test. These alerts occur when alerts T051 and T055 are active while the appropriate condensing temperature is greater than 150°F. These alerts reset automatically. The cause of the alert is usually an overcharged system, high outdoor ambient temperature coupled with dirty outdoor coil, plugged filter drier, or a faulty high-pressure switch. See Alerts T051 and T055 for diagnostic procedure.

Alert Codes T133 and T134 — Circuit Low Refrigerant Pressure

Alert codes T133 and T134 are for circuits A and B respectively. These alerts have “Service Test” text that will be displayed if the alert occurred during service test. These alerts occur when the compressor is operating and the evaporating temperature (converted from the suction pressure) is less than configured low suction control levels, Configura-

tion



COOLSSTSST.1 (Low Suction — Level 1) or

SST.2 (Low Suction — Level 2) or SST.3 (Low Suction Level

3). The circuit SST value must be less than SST.1 (for 5 min- utes), SST.2 (for 4 minutes), or SST.3 (for 3 minutes when us- ing the economizer and 1.5 minutes when not using the economizer) for the alert to occur. When the outdoor temperature is less than 40°F, the above values are reduced 1°F for every 2°F the OAT is below 40°F. An alert will also occur if the circuit SST value is less than SST.3 –5°F for 20 seconds and the out- door temperature is above 40°F. All the above timers will reset if the suction temperature rises above SST.O for 1 minute. These alerts cause a strike for the respective circuit. If the OAT is less than 10°F, the circuit will shut down without a strike. These alerts will activate when the coil becomes frosted. However, during the 15-minute reset period, the coils will thaw and strike should clear at restart if there is nothing else wrong with the circuit. The alert resets automatically. The cause of the alert is usually low refrigerant charge, dirty filters, evaporator fan operating backwards, loose or broken belt, plugged filter drier, faulty transducer, excessively cold return air, or stuck open economizer when the ambient temperature is low.

Alert Codes T143 and T144 — Circuit Failure to Pressurize

Alert codes T143 and T144 are for circuits A and B respectively. These alerts have “Service Test” text that will be displayed if the alert occurred during service test. These alerts occur when the compressor turns on and the suction pressure does not drop at least 10 PSIG in the first 20 seconds. If the OAT is less than 40°F (4.4°C) the suction only has to drop 5 PSIG. This alert causes a strike for the circuit. The alert resets automatically. The cause of the alert is usually compressor wiring causing reverse rotation or a faulty compressor.

Alarm Code T153 — Real Time Clock Hardware Failure

The alert occurs when the RTC clock chip on the MBB is not responding. Time and date functions will not operate, such as local occupancy schedules. The unit will default to 24/7 unoccupied mode. Recovery is automatic but MBB board replacement may

be necessary. Cycling power to the control and reconfiguring the time and date should be tried before board replacement.

Alarm Code A154 — Serial EEPROM Hardware Failure

The unit will completely shut down. The serial EEPROM chip on the MBB which stores the unit’s configuration is not responding. Recovery is automatic, but MBB board replacement may be necessary. Cycling the power to the control should be tried before board replacement.

Alarm Code T155 — Serial EEPROM Storage Failure Error

Configuration data in the serial EEPROM chip can not be verified. The unit will run to last know good values or defaults, and therefore operating errors may occur. Recovery is automatic but MBB board replacement may be necessary. Cycling power to the control and reconfiguring the control points should be tried before board replacement.

Alarm Code A156 — Critical Serial EEPROM Storage Fail Error

The unit will completely shut down. Critical configuration data in the serial EEPROM chip can not be verified. Recovery is automatic but MBB board replacement may be necessary. Cycling power to the control and reconfiguring the critical control points should be tried before board replacement. Check the configurations for the following critical points:

Configuration Configuration Alarm Code A157 — A/D Hardware Failure

The unit will completely shut down. The analog to digital conversion chip on the MBB has failed. Recovery is automatic but MBB board replacement may be necessary. Cycling power to the control should be tried before board replacement.

Alarm Codes A163 and A164 — Circuit Down due to Failure

Alarm codes A163 and A164 are for circuits A and B respectively. These alarms have “Service Test” text that will be displayed if the alarm occurred during service test. These alarms occur when a circuit has 3 strikes. Use the scrolling marquee display to reset the alarm. Investigate the alarm that caused the strikes to occur.

Alert Code T173 — Loss of Communication with the Energy Management Module

This alert occurs when the MBB cannot communicate with the EMM. These units do not currently support any operation with the EMM. This alert is caused by an internal force to look for the EMM board. When this happens, reload software on the MBB and do not restore configurations, the factory configurations must be used at first. Replace the MBB if alert continues.

Alert Code T175 — Loss of communication with VFD This alert occurs when the Indoor Fan Type (Configuration

I.FANFTYP) is set to 1 and the MBB cannot communicate

with the VFD. The control will shutdown the unit and prevent normal operation. This alert will automatically reset when communication is established again. This alert is usually caused by a wiring problem or a incorrect configuration in the VFD or the MBB.

Alert Code T179 — Loss of Communication with the Economizer Control Board

This alert occurs when the MBB cannot communicate with the ECB. Economizer operation will be disabled. This is usually caused by a wiring problem. If a relative humidity sensor is installed and configured but there is not an ECB installed on the unit, this alert will be generated (the ECB is required for RH sensor operation). Investigate using the Low Voltage Schematic, check that the ECB address is correct, and verify the resistance between pins on the LEN connections.



COOLN.CIR (Number of Circuits)



HMZRREHT (Humidi-MiZer Equipped)



Alert Code T180 — Loss of Communication with the Economizer Actuator

This alert occurs when the ECB cannot communicate with the Belimo Actuator. If the analog signal is connected properly, the economizer can still be controlled through it. This is usually caused by a wiring problem, actuator failure, or the wrong actuator. Investigate using the Low Voltage Schematic. Make sure the actuator is a MFT communication actuator and verify the feedback signal from the actuator is correct.

Alert Code T181 — Loss of communication with Outside Air Unit

This alert occurs when the Outdoor Air Unit Type (Configuration



OAUOA.TY) is not set to 0 and the OAU Operating

Mode (Run Status cated in the past 3 minutes. The control will reset all OAU data. This alert will automatically reset when communication is established again. This alert is usually caused by a wiring problem or a problem with the OAU communication.

Alarm Code A200 — Linkage Timeout - Comm Failure

This alarm occurs when the MBB fails to communicate with a Linkage device. This only occurs when the MBB has previously communicated with a Linkage device since last power cycle. If a back up sensor was not installed the T074 alert will occur shortly after this one. Reset power to the unit and verify Linkage is communicating.

Alarm Code A404 — Fire Shutdown

This alarm occurs when the shutdown input is either open or closed depending upon its configuration. This alarm is usually caused by an auxiliary device that is trying to shut down the unit, e.g., smoke detector. The configuration for this switch input can be found at variable Configuration Verify that the configuration is set correct, verify the wiring and auxiliary device. This alarm resets automatically.

Alert Code T408 — Dirty Air Filter

This alert occurs when the Filter Status switch senses a plugged filter for 120 continuous seconds after the indoor fan has been running for 10 seconds. Because the Dirty Air Filter switch can be configured normally opened or closed, the switch might be open or closed. The configuration for this switch input can be found at variable Configura-

tion



UNITFL.SW. Verify that the configuration is set cor-

rect, verify the wiring and filter status switch. The hose should be connected to the low side of the switch. This alert resets automatically.

Alert Code T409

There are 2 different texts for this alert code. Pressing enter and esc on the marquee or navigator to expand the T409 alert will show you one of the below alerts. Make sure the expanded text is read correctly before troubleshooting.

• Fan Status Switch On, Fan Contactor Off

This alarm occurs when the fan status switch has sensed that the indoor fan has been on for 10 seconds and the indoor fan feedback has determined that the indoor fan should be off. Because the Fan Status switch can be configured normally opened or closed, the switch might be open or closed. The configuration for this switch input can be found at Configura-

tion



UNITFN.SW. Verify that the configuration is set cor-

rectly. Verify the wiring and fan status switch. The hose should be connected to the high side of the switch. If the IDF is configured to shut down the unit when this alarm occurs (Configu-

ration



I.FANIDF.F = YES), then this alarm can only be

reset manually and the unit is shut down. If the IDF is not configured to shut the unit down when this alarm occurs (IDF.F = NO), then this alarm resets automatically and no specific control action is taken.

• Fan Status Switch Off, Fan Contactor On



OAUOA.OP) has not been communi-



UNITFS.SW.

This alert occurs when the fan status switch has sensed that the indoor fan has been off for 10 seconds and the indoor fan feedback has determined that the indoor fan should be on. Because the Fan Status switch can be configured normally opened or closed, the switch might be open or closed. The configuration for this switch input can be found at Configuration that the configuration is set correctly. Verify the wiring and fan status switch. The hose should be connected to the high side of the switch. If the IDF is configured to shut down the unit down when this alert occurs (Configuration this alarm can only be reset manually and the unit is shut down. If the IDF is not configured to shut the unit down when this alert occurs (IDF.F = NO), then this alert resets automatically and no spe- cific control action is taken.

Alert Code T410

• R-W1 Jumper Not Installed in Space Temp Mode

This alert occurs when the control mode is Space Temperature mode via Auto Select or Space Temp Select, yet there is no power to W1. Verify that space temperature mode is the desired mode or add jumper between R and W1 (on TB). This alert resets automatically.

• R-W1 Jumper Must be Installed to Run Heat in Service Test

This alert occurs when a request for a heat output has occurred yet the W1 input is not high. A jumper must be installed between R and W1 (on TB) when trying to test heat in Service Test. The alert will clear when Service Test is exited or if another Service Test mode is selected. Remove jumper when done using Service Test if the unit is operating with a thermostat. The jumper should only be left in place if the unit is operating with a space temperature probe.

Alert Code T411 — Thermostat Y2 Input Activated without Y1 Activated

This alert occurs in Thermostat mode when Y2 is energized and Y1 is not. Verify thermostat and thermostat wiring. When Y2 turns On, the software will behave as if Y1 and Y2 are both On. When Y2 turns Off, the software will behave as if Y1 and Y2 are both Off. This alert resets automatically when Y1 is turned On.

Alert Code T412 — Thermostat W2 Input Activated without W1 Activated

This alert occurs in Thermostat mode when W2 is energized and W1 is not. Verify thermostat and thermostat wiring. When W2 turns On, the software will behave as if W1 and W2 are both On. When W2 turns Off, the software will behave as if W1 and W2 are both Off. This alert resets automatically when W1 is turned On.

Alert Code T413 — Thermostat Y and W Inputs Activated Simultaneously

This alert occurs in Thermostat mode when Y1 or Y2 is energized simultaneously with W1 or W2. Verify thermostat and thermostat wiring. The software will enter either the cooling or heating mode depending upon which input turned on first. This alert resets automatically when Y1 and Y2 are not on simultaneously with W1 and W2.

Alert Code T414

There are 10 different alerts under this one alert code. Pressing enter and esc on the marquee or navigator to expand the T414 alert will show you one of the below alerts. All these alerts are generated by the Belimo actuator and reported to the ECB. These alerts can only occur if the ECB is controlling the actuator digitally through MFT.

• Economizer Damper Actuator Out of Calibration

This alert occurs when the economizer actuator reports a control angle (Operating Modes minimum control angle (Configuration Initiate economizer calibration (Service Test



UNITFN.SW. Verify



I.FANIDF.F = YES), then

ECONC.ANG) less than the



ECONM.ANG).



INDPE.CAL) using the Service Test menu. The economizer calibration procedure will try to find new maximum open and closed positions. If the alert does not clear automatically after the calibration procedure is complete, investigate what is limiting economizer rotation. After that step, run another calibration, but first power off unit (spring return the damper), loosen the actuator clamp, and while pushing the damper closed, tighten the clamp. This alert resets automatically.

• Economizer Damper Actuator Torque Above Load Limit

This alert occurs when the actuator load is too high. Investigate to determine what is increasing damper load, and verify that the actuator is the correct size for the unit. This alert resets automatically.

• Economizer Damper Actuator Hunting Excessively

This alert occurs when the commanded damper position is changing too rapidly. The stop jog ratio must be less than 21% to clear this alert. Leave the actuator powered with no signal for a few hours to allow the ratio to decrease (may have to wait longer than a few hours). If the alert continues, determine if the ECB or actuator is bad. This alert resets automatically.

• Economizer Damper Stuck or Jammed

This alarm occurs when the actuator is no longer moving and the actual position is greater than or less than 3% of the commanded position for 20 seconds. Investigate what is stopping the rotation of the actuator and fix. This alert resets automatically.

• Economizer Damper Actuator Mechanical Failure

This alert occurs when the actuator senses a catastrophic failure. Investigate actuator and replace if necessary. This alert resets automatically.

• Economizer Damper Actuator Direction Switch Wrong Position

This alert occurs when the economizer damper direction switch is in the wrong position. The direction switch should be in the clockwise position and the actuator should be mounted so that the CW face of the actuator is accessible. Correct if necessary.

This alert clears automatically.

• Excess Outdoor Air

In this failure mode the economizer provides an excessive level of ventilation, usually much higher than is needed for design minimum ventilation.

• Economizer Economizing When It Should Not

In this case, conditions are such that the economizer should be at minimum ventilation position but for some reason it is open beyond the correct position.

• Economizer Not Economizing When It Should

In this case, the economizer should be enabled, but for some reason it is not providing free cooling.

• Damper Not Modulating

This issue represents a stuck, disconnected, or otherwise inoperable damper that does not modulate open and close.

Alert Code T415 — IAQ Input Out of Range

This alert occurs when the IAQ input (on ECB) is less than 3.5 mA and the sensor is configured as installed. IAQ operation will be disabled. Check sensor and wiring. This alert clears automatically.

Alert Code T416 — OAQ Input Out of Range

This alert occurs when the OAQ input (on ECB) is less than

3.5 mA and the sensor is configured as installed. OAQ operation will be disabled. Check sensor and wiring. This alert clears automatically.

Alert Code T418

There are 4 different alerts under this one alert code. Pressing enter and esc on the marquee or navigator to expand the T418

alert will show you one of the below alerts. All these alerts are generated by the OAU device and reported to the MBB. These alerts can only occur if the Outdoor Air Unit Type (Configura-

tion



OAUOA.TY) is not set to 0. Control action is only tak-

en on the OAU side and these alerts will reset automatically when the OAU clears them. Refer to the EnergyX Supplemental Installation Instructions for more information on these alarms.

• OAU Motor Failure

This alert occurs when the OAU Motor Failure Alarm (Operat-

ing Modes



OAUALM.1) is on. This is usually due to mo-

tor status reporting a failure on the OAU.

• OAU Dirty Filter

This alert occurs when the OAU Dirty Filter Alarm (Operating

Modes



OAUALM.2) is on. This is usually due to filter sta-

tus reporting a dirty filter on the OAU.

• OAU Low CFM

This alert occurs when the OAU Low CFM Alarm (Operating

Modes



OAUALM.3) is on. This is usually due to OAU not

capable of achieving proper CFM. If unit is equipped with a VFD on the indoor fan, the configuration OAU Fan Boost En-

Table 14 — ComfortLink Alarm Codes

able is set to yes (Configuration



OAUEFBE = Yes), and

this alarm is active for 10 minutes, the fan will be commanded to the next highest configured fan speed. If this alarm is still active after another 10 minutes, the fan will again change to the next highest configured fan speed, and so on every 10 minutes until the maximum speed is commanded. The fan will stay at this override commanded speed until this alarm clears and a different function changes the commanded speed.

• OAU General Alarm

This alert occurs when the OAU Alarm (Operating Modes



OAUALM.4) is on. Refer to the specific OAU documen-

tation for details.

Alert Code A420 — Supply VFD Fault

This alarm occurs when the VFD has faulted and communicates it to the Main Base Board (MBB). The last VFD fault number can be viewed as VFD1 Last Full code (Run Sta-

tus



S.VFDLFC). Refer to VFD major component section

for details on its alarms and faults. The alarm will shut down the unit if the fan ramps down to 0%. This alarm will automatically reset or can be reset through the display.

ALARM

ALERT

NUMBER

Compressor A1 Safety Trip Service Test — Compressor A1

T051

T055

T064

T065

T066

T067

T073

T074

T075

T076 Return Air Thermistor Failure

T077

T092

T093

T102

T103

T110

Safety Trip Compressor A1 Detected After

Turnoff Service Test — Compressor A1

Detected After Turnoff Compressor B1 Safety Trip Service Test — Compressor B1

Safety Trip Compressor B1 Detect After Turnoff Turn off all compressors Automatic Service Test — Compressor B1

Detected After Turnoff Circuit A Saturated Condensing

Temp Thermistor Failure Circuit B Saturated Condensing

Temp Thermistor Failure Circuit A Saturated Suction

Temperature Thermistor Failure Circuit B Saturated Suction

Temperature Thermistor Failure Outdoor Air Temperature

Thermistor Failure Space Temperature Thermistor

Failure

Supply Air Temperature Thermistor Failure

Space Relative Humidity Sensor Failure

Circuit A Suction Pressure Transducer Failure

Circuit B Suction Pressure Transducer Failure

Compressor A1 Current Sensor Failure

Circuit A Loss of Charge Service Test — Circuit A Loss of

Charge

DESCRIPTION

ACTION TAKEN BY

CONTROL

Add Strike for Circuit A Automatic

Turn off all compressors Automatic Welded contactor

Add Strike for Circuit B Automatic

Limited Diagnostic Automatic

No Circuit A Cooling Automatic Circuit A Suction transducer internally forced inactive

No Circuit B Cooling Automatic Circuit B Suction transducer internally forced inactive

No cooling with economizer Automatic

If U.CTL = 3, then no heating or cooling

No cooling with economizer and No adaptive compressor staging

If RAT.S = Yes, then no differential Dry Bulb control

If RH.S = Yes, then no indoor humidity control

Lockout Circuit A Manual

Lockout Circuit B Manual

If CS.A1 = Enable, then no T051 current alarm

If CS.B1 = Enable, then no T055 current alarm

Lockout Circuit A Manual Low refrigerant or faulty suction pressure transducer

RESET

METHOD

Automatic

PROBABLE CAUSE

High-pressure switch open. Compressor internal protection open. Wiring error

Welded contactor

Faulty, shorted, or open thermistor caused by wiring error or loose connection.

Faulty, shorted, or open sensor caused by wiring error or loose connection.

Faulty transducer, faulty 5-V power supply, or loose connection

Table 14 — ComfortLink Alarm Codes (cont)

ALARM

ALERT

NUMBER

T111

T126

T127

T133

T134

T143

T144

T153 Real Timeclock Hardware Failure

A154 Serial EEPROM Hardware Failure Unit Shutdown Automatic Software failure or MBB failure

T155

A156

A157 A/D Hardware Failure Unit Shutdown Automatic Software failure or MBB failure

A163

A164

T173

T175 Loss of communication with VFD Unit Shutdown Automatic

T179

T180

T181

A200

A404 Fire Shutdown Unit Shutdown Automatic Smoke detected by smoke detector T408 Dirty Air Filter Alert Generated Automatic Dirty Filter

T409

T410

T411

Circuit B Loss of Charge Service Test — Circuit B Loss of

Charge Circuit A High Discharge Pressure Service Test — Circuit A High

Discharge Pressure Circuit B High Discharge Pressure Service Test — Circuit B High

Discharge Pressure Circuit A Low Refrigerant Pressure

Service Test — Circuit A Low Refrigerant Pressure

Circuit B Low Refrigerant Pressure

Service Test — Circuit B Low Refrigerant Pressure

Circuit A Failure To Pressurize Service Test — Circuit A Failure to

Pressurize Circuit B Failure To Pressurize Service Test — Circuit B Failure to

Pressurize

Serial EEPROM Storage Failure Error

Critical Serial EEPROM Storage Fail Error

Circuit A Down Due to Failure Service Test — Circuit A Down Due

to Failure Circuit B Down Due to Failure Service Test — Circuit B Down Due

to Failure Loss of communication with the

Energy Management Module

Loss of communication with the Economizer Control Board

Loss of communication with the Economizer Actuator

Loss of communication with Outside Air Unit

Linkage Timeout Error — Comm Failure

Fan Status Switch ON, fan commanded off

Fan Status Switch OFF, fan commanded on

R-W1 Jumper Not Installed in Space Temp Mode

R-W1 Jumper Must Be Installed to Run Heat In Service Test

Thermostat Y2 Input Activated without Y1 Activated

DESCRIPTION

ACTION TAKEN BY

CONTROL

Lockout Circuit B Manual Low refrigerant or faulty suction pressure transducer

Shutdown Circuit A Automatic

Shutdown Circuit B Automatic

Add Strike for Circuit A Automatic

Add Strike for Circuit B Automatic

Add Strike for Circuit A Automatic Wiring causing reverse rotation or faulty compressor

Add Strike for Circuit B Automatic Wiring causing reverse rotation or faulty compressor

No time and date schedule operation

Unit operation errors Automatic Software failure or MBB failure

Unit Shutdown Automatic Software failure or MBB failure

Lockout Circuit A Manual

Lockout Circuit B Manual

No action Automatic MBB Software failure, reload software or replace board

No economizer operation Automatic

No economizer operation Automatic Communication wiring problem with actuator.

Reset OAU data Automatic Wiring Problem or OAU communication failure

No Linkage Operation fall back to local SPT

If IDF.F = Yes, then Unit Shutdown

Unable to run heat Automatic Missing jumper wire

Unable to Test Heat Outputs

Run unit as if Y2 and Y1 are On

RESET

METHOD

An overcharged system, high outdoor ambient temperature coupled with dirty outdoor coil, plugged filter drier, or a faulty high-pressure switch.

Low refrigerant charge, dirty filters, evaporator fan turning backwards, loose or broken fan belt, plugged filter drier, faulty transducer, excessively cold return air, or stuck open economizer when the ambient temperature is low.

Automatic

If IDF.F =

YES, then

Manual,

otherwise automatic

If IDF.F =

YES, then

Manual,

otherwise automatic

Automatic Missing jumper wire

Automatic Bad Thermostat or Thermostat Wiring

No time/date configured, software failure, or MBB failure

Circuit has 3 strikes or has been locked out by another alarm

Communication connection bad or miswired, misconfigured VFD.

Communication wiring problem with ECB or faulty MBB or ECB

Received a table write from Linkage before, now not receiving any linkage commands

Bad Fan Status Switch. Configuration incorrect.

Tripped Circuit Breaker. Broken belt. Bad indoor fan motor. Configuration incorrect. Bad fan status switch.

PROBABLE CAUSE

Table 14 — ComfortLink Alarm Codes (cont)

ALARM

ALERT

NUMBER

T412

T413

T414

T415 IAQ Input Out of Range No IAQ Operations Automatic

T416 OAQ Input Out of Range No OAQ Operations Automatic

T418

A420 Supply VFD Fault Unit shutdown Automatic VFD fault occurred, review VFD faults.

Thermostat W2 Input Activated without W1 Activated

Thermostat Y and W Inputs Activated Simultaneously

Economizer Damper Actuator Out of Calibration

Economizer Damper Actuator Torque Above Load Limit

Economizer Damper Actuator Hunting Excessively

Economizer Damper Stuck or Jammed

Economizer Damper Actuator Mechanical Failure

Economizer Damper Actuator Direction Switch Wrong

Excess Outdoor Air Alert Generated Automatic Economizer Economizing When It

Should Not Economizer not Economizing When

it Should Damper Not Modulating Alert Generated Automatic

OAU Motor Failure Alert generated Automatic Check OAU motors for failure OAU Dirty Filter Alert generated Automatic Check/change OAU filters OAU Low CFM Alert generated Automatic Check OAU air flow OAU General Alarm Alert generated Automatic Check OAU

DESCRIPTION

ACTION TAKEN BY

CONTROL

Run unit as if W2 and W1 are On

Run unit in mode activated first

Alert Generated Automatic

Alert Generated Automatic Actuator load too high. Check damper load.

Alert Generated Automatic Damper position changing too quickly.

Alert Generated Automatic

Alert Generated Automatic Check actuator and replace if necessary.

Alert Generated Automatic Actuator direction control switch (CCW, CW) wrong.

Alert Generated Automatic

RESET

METHOD

Automatic Bad Thermostat or Thermostat Wiring

Calibrate economizer (E.CAL). If problem still exist then determine what is limiting economizer rotation.

No economizer motion. Check damper blades, gears, and actuator.

Bad sensor, bad wiring, or sensor configured incorrectly.

PROBABLE CAUSE

LEGEND

ECB — Economizer Control Board IGC — Integrated Gas Controller IAQ — Indoor Air Quality MBB — Main Base Board OAQ — Outdoor Air Quality OAT — Outdoor-Air Thermistor OAU — Outdoor Air Unit VFD — Variable Frequency Drive

Control Module Communication

RED LED Proper operation of the MBB and ECB control boards can be

visually checked by looking at the red status LEDs. When operating correctly, the red status LEDs should blink in unison at a rate of once every 2 seconds. If the red LED on the ECB is not blinking, check the DIP switch positions on the board. If the red LEDs are not blinking in unison, verify that correct power is being supplied to all modules. A blinking red LED at the rate of once per second means that software is not loaded on the board. Also, be sure that the board is supplied with the current software. If necessary, reload current software. A board LED that is lit continuously should be replaced.

GREEN LED The MBB and ECB each have one green LED. The Local

Equipment Network (LEN) LED should always be blinking whenever power is on. If LEN LED is not blinking, check LEN connections for potential communication errors (MBB J3, J4, and J5). Communication between modules is accomplished by a 3-wire sensor bus. These 3 wires run in parallel from module to module. The J4 connector on the MBB also provides both

Table 15 — LEN and CCN Communication Resistances

power and communication directly to the scrolling marquee display. The J5 connector on the MBB provides a LEN interface at the field connection terminal (TB).

YELLOW LED The MBB has one yellow LED which is used to indicate CCN

communication activity. The Carrier Comfort Network

(CCN)

LED will blink during times of network communication.

Communication Failures

If the scrolling marquee or Navigator display Communication Failure or the green or yellow LEDs do not flash on the boards then the problem could be the communication chip on one of the control boards (MBB or ECB). Disconnect all the LEN and CCN plugs from the board and use an ohm meter to measure the resistance on the communication pins of the boards to determine if the board is bad. If the reading is less than half the value indicated in Table 15, then the board needs to be replaced.

NOTE: The resistive values should be read when the board is powered off and the unit is locked out.

Device

MBB

ECB

Board Serial

Number

Prior to 4702N

Starting 4702N

Prior to 0803N

Starting 0803N

(LEN) Resistance between Pins/Connector (CCN) Resistance between Pins/Connector

Pins 1 to 3 Pins 1 to 2 Pins 2 to 3 Pins 5 to 7 Pins 5 to 6 Pins 6 to 7

15K 

J3, J4, & J5

18.9K 

J3, J4, & J5

5.9K 

18.9K 

7.5K 

J3, J4, & J5

9.9K 

J3, J4, & J5

5.2K 

9.9K 

7.5K 

J3, J4, & J5

9.9K 

J3, J4, & J5

5K 

9.9K 

15K 

18.9K 

———

7.5K 

9.9K 

7.5K 

9.9K 

Cooling Troubleshooting

Use the scrolling marquee display or a CCN device to view the cooling status display and the cooling diagnostic display (see Appendix A) for information on the cooling operation. Check the current alarms and alarm history for any cooling alarm codes and correct any causes. (See Table 14.) Verify any

unique control configurations per installed site requirements or accessories.

If alarms conditions are corrected and cleared, operation of the compressors and fans may be verified by using the Service Test mode. (See Table 6.) See Table 16 for general cooling service analysis.

Table 16 — Cooling Service Analysis

PROBLEM CAUSE REMEDY

Compressor and Fan Will Not Start. Power failure. Call power company.

Fuse blown or circuit breaker tripped. Replace fuse or reset circuit breaker. Disconnect off. Power disconnect. Compressor time guard to prevent short cycling. Check using ComfortLink scrolling marquee. Thermostat or occupancy schedule set point not

calling for Cooling. Outdoor temperature too low. Check Compressor Lockout Temperature using

Active alarm. Check active alarms using ComfortLink scrolling

Compressor Cycles (other than normally satisfying thermostat).

Compressor Operates Continuously. Unit undersized for load. Decrease load or increase size of unit.

Excessive Condenser Pressures. Loose condenser thermistors. Tighten thermistors.

Condenser Fans Not Operating. No Power to contactors. Fuse blown or plug at motor loose. Excessive Suction Pressure. High heat load. Check for sources and eliminate

Suction Pressure Too Low. Dirty air filters. Replace air filters.

Compressor not running but ComfortLink Status show it is on.

Insufficient line voltage. Determine cause and correct. Active alarm. Check active alarms using ComfortLink scrolling

Thermostat or occupancy schedule set point too low.

Dirty air filters. Replace filters. Low refrigerant charge. Check pressure, locate leak, repair, evacuate,

Condenser coil dirty or restricted. Clean coil or remove restriction.

Dirty condenser coil. Clean coil. Refrigerant overcharge. Recover excess refrigerant. Faulty TXV. 1. Check TXV bulb mounting and secure tightly

Condenser air restricted or air short cycling. Determine cause and correct. Restriction in liquid tube. Remove restriction.

Faulty TXV. 1. Check TXV bulb mounting and secure tightly

Refrigerant overcharged. Recover excess refrigerant.

Low refrigerant charge. Check pressure, locate leak, repair, evacuate,

Faulty TXV. 1. Check TXV bulb mounting and secure tightly

Insufficient evaporator airflow. Check belt tension. Check for other restrictions. Temperature too low in conditioned area (low

return-air temperature). Condensate overflow switch, High pressure, or

Freeze protection thermostat has tripped.

Check using ComfortLink scrolling marquee.

ComfortLink scrolling marquee.

marquee.

Reset thermostat or schedule set point.

and recharge.

to suction line and insulate.

2. Replace TXV (and filter drier) if stuck open or closed.

to suction line and insulate.

2. Replace TXV (and filter drier) if stuck open or closed.

and recharge.

to suction line and insulate.

2. Replace TXV (and filter drier) if stuck open or closed.

Reset thermostat or occupancy schedule.

Check Alarms. (T051 or T055), check switches and conditions that can cause their trips.

LEGEND

TXV — Thermostatic Expansion Valve

Humidi-MiZer™ Troubleshooting

Use the unit scrolling marquee display or a CCN device to view the cooling status display and the cooling diagnostic display (see Appendix A) for information on the cooling operation and the related Humidi-MiZer operation. Check the current alarms and alarm history for any cooling alarm codes and correct any causes. (See Table 14.) Verify any unique control

If alarm conditions are corrected and cleared, operation of the compressors, fans, and Humidi-MiZer valves may be verified by using the Service Test mode (see Table 6.) In addition to general cooling service analysis (see Table 16), see Table 17 for general Humidi-MiZer service analysis.

NOTE: Wiring, operation, and charge are different on a HumidiMiZer unit compared to a standard unit.

configurations per installed site requirements or accessories.

Table 17 — Humidi-MiZer Service Analysis

PROBLEM CAUSE REMEDY

Subcooling Reheat Mode Will Not Activate.

Hot Gas Reheat Mode Will Not Activate.

No Dehumidification Demand. Relative humidity setpoint is too low —

CRC Relay Operation. No 24V signal to input terminals. Check using Cool

RLV, CLV or LDV Valve Operation No 24V signal to input terminals. Check using Cool

RDV Valve Operation. (NOTE: Normally Closed When De-energized)

Low Latent Capacity in Subcooling or Hot Gas Reheat Modes.

Low Sensible Capacity in Normal Cool or Subcooling Reheat Modes.

Low Suction Pressure and High Superheat During Normal Cool Mode.

General cooling mode problem. See Cooling Service Analysis (Table 16). No dehumidification demand. See No Dehumidification Demand, below. CRC relay operation. See CRC Relay Operation, below. Circuit RLV, CLV or LDV valve problem. See CLV, RLV or LDV Valve Operation, below. General cooling mode problem. See Cooling Service Analysis (Table 16). No dehumidification demand. See No Dehumidification Demand, below. CRC relay operation. See CRC Relay Operation, below. Circuit RLV, CLV or LDV valve problem. See CLV, RLV or LDV Valve Operation, below. Circuit RDV valve is not open. See RDV Valve Operation, below. Outdoor temperature too low. Check Reheat2 Circuit Limit Temperatures

Humidistat Relative humidity setpoint is too low —

RH sensor. Software configuration error for accessory

humidistat.

Software configuration error for accessory humidity sensor.

No humidity signal. Check wiring. Check humidistat or humidity sensor.

No power to output terminals. Check wiring. Relay outputs do not change state. Replace faulty relay.

Solenoid coil burnout. Check continuous over-voltage is less than 10%.

Stuck valve. Replace valve. Replace filter drier. No 24V signal to input terminals. Check using Cool

Solenoid coil burnout. Check continuous over-voltage is less than 10%.

Stuck valve. Replace valve. Replace filter drier. CLV valve open or leaking. See CLV Valve Operation, above.

RDV valve open or leaking. See RDV Valve Operation, above.

General cooling mode problem. See Cooling Service Analysis (Table 16). RDV valve open or leaking. See RDV Valve Operation, above.

(Configuration ComfortLink scrolling marquee.

Check/reduce setting on accessory humidistat.

Check Space RH Setpoints (Setpoints and occupancy using ComfortLink scrolling marquee.

Check Space Humidity Switch (Configuration marquee.

Check RH Sensor on OAQ Input (Configuration marquee.

TestHMZRCRC) using ComfortLink scrolling marquee. Check MBB relay output. Check wiring. Check transformer and circuit breaker.

Test



HMZRCRC) using ComfortLink scrolling marquee.

Check CRC Relay Operation. Check Wiring. Check transformer and circuit beaker or fuses.

Check under-voltage is less than 15%. Check for missing coil assembly parts. Check for damaged valve enclosing tube.

TestHMZRRHV.A or RHV.B) using ComfortLink scrolling marquee.

Check MBB relay output. Check wiring. Check transformer and circuit breaker or fuses.

Check under-voltage is less than 15%. Check for missing coil assembly parts. Check for damaged valve enclosing tube.



HMZRRA.LO and RB.LO) using



RH.SP and RH.UN)



UNITRH.SW) using ComfortLink’scrolling



UNITRH.S) using ComfortLink scrolling



Reheat1 Valve Test (Service



Reheat1 Valve Test (Service



Reheat1 Valve Test (Service

Table 17 — Humidi-MiZer Service Analysis (cont)

PROBLEM CAUSE REMEDY

Low Suction Pressure and High Discharge Pressure.

RDV Valve Cycling On/Off. Hot Gas Reheat mode low suction

Circuit B Will Not Operate With Circuit A Off.

LEGEND

CLV — Cooling Liquid Valve CRC — Cooling/Reheat Control RDV — Reheat Discharge Valve RH — Relative Humidity RLV — Reheat Liquid Valve

General cooling mode problem. See Cooling Service Analysis (Table 16). Both RLV and CLV valves closed. See RLV and CLV Valve Operation, above.

pressure limit. Normal operation. Motormaster outdoor

fan control requires operation of circuit A.

Normal Operation During Mixed Circuit Subcooling and Hot Gas Reheat Modes at Lower Outdoor Temperatures.

None

Economizer Troubleshooting

Use the unit scrolling marquee display or a CCN device to view the economizer status display and the economizer diagnostic display (see Appendix A) for information on the economizer operation. Check the current alarms and alarm history for any economizer alarm codes and correct any causes. (See Table 14.) Verify any unique control configurations per installed site requirements or accessories. If alarms conditions are corrected and cleared, operation of the economizer may be verified by using the Service Test mode (see Service Test section and Table 6). The following steps specify how to test the economizer using the scrolling marquee display. See Table 18 for general economizer service analysis.

1. Enter the Service Test main menu on the display.

2. Enter TEST and turn ON test mode. A password may be needed in order to turn ON the Service Test. The default password is 1111.

3. Return to the main level of Service Test.

4. Enter the INDP submenu and enter an initial value for ECON. This will drive the economizer damper to the specified position. Continue to adjust the ECON value to make sure the economizer opens and closes.

5. Because of a mechanical problem with the economizer, the actuator might acquire a new degree of rotation which is less than M.ANG. If this occurs, a “T414 Economizer Damper Actuator Out of Calibration” alert will be generated. This alert can only occur if the economizer is using digital communications (Configuration

= 1 or 2). The economizer calibration procedure (Service Te st



IND.PE.CAL) will reconfigure the actuator to

the new fully closed and fully open positions. To implement the calibration procedure, change E.CAL from OFF to ON. E.CAL will remain ON as long as the calibration procedure is being implemented (as long as 5 minutes). During the calibration procedure the actuator will close fully and then open fully. After the calibration is complete, the degree of rotation should be greater than M.ANG, causing the T414 alert to clear. If the T414 alert does not clear, check the economizer damper for other mechanical problems.



ECONE.CTL

6. Return to Service Test



TEST and turn OFF test mode.

This will cause the unit to return to normal operation.

Title 24 FDD Status Points

The control shall utilize the following points to determine whether a damper is mechanically disconnected:

ECONO — Economizer Installed — Flag indicating whether an economizer is installed

RAT — Return Air Temperature SAT — Supply Air Temperature OA_TEMP — Outdoor Air Temperature OCCUPIED — Currently Occupied — Flag indicating wheth-

er currently in occupied mode IDF_MODE — Indoor Fan Mode — Current indoor (supply)

fan mode. IDFSTATE — Indoor Fan State FANSPEED — Commanded Fan Speed — Commanded fan

speed ECONOCMD — Econo Commanded Position — Economizer

position as commanded by the ComfortLink control ECONOPOS — Econo Actual Position — Economizer posi-

tion as reported by the actuator ECONCOOL — OK To Use Economizer? — Flag indicating

whether the economizer is able to help with cooling without taking into account whether the supply fan is on.

OKTSTMDA — OK Test Mech. D/C Act — Flag indicating whether the control will attempt to test for a mechanically disconnected actuator.

T24PRSAT — Title 24 Previous SAT — SAT sample taken at T24ECSMP

T24ECSMP — Title 24 Econ Samp Pos — Economizer position when T24PRSAT taken

T24SATCT — Title 24 SAT Check Time — Time when next SAT sample will be taken or test for mechanically disconnected actuator will be performed.

ELAPSECS — Elapsed Seconds — Current ComfortLink control elapsed seconds

Table 18 — Economizer Service Analysis

PROBLEM POSSIBLE CAUSE REMEDY

Damper Does Not Move. Indoor Fan is off. Check for proper thermostat connection.

Unit is not configured for continuous fan operation and the thermostat is not calling for heating or cooling.

Unit is in Unoccupied mode and there is no call for heating or cooling.

Tripped circuit breaker. No power to the unit. Unit is off via CCN command.

Actuator is unplugged at motor or at economizer board.

Unit is not configured for economizer. Configure unit for economizer per the

Outdoor-air temperature is above economizer high temperature lockout.

Outdoor-air temperature is below economizer low temperature lockout.

Communication loss to economizer board. Check wiring connections. Damper is jammed. Identify the obstruction and safely remove.

Economizer Operation is Limited to Minimum Position.

Economizer Position is Less Than Minimum Position.

Economizer Does Not Return to Minimum Position.

Damper Does Not Close on Power Loss. Damper is jammed or spring return is

Outdoor Damper Does Not Fully Close at 0% or Fully Open at 100%.

Economizer is Not at Configured Minimum Position

Minimum position is set incorrectly. Adjust minimum position setting. Outdoor-air temperature is above economizer

high temperature lockout.

Outdoor-air temperature is below economizer low temperature lockout.

Enthalpy or differential dry bulb are preventing free cooling.

Outdoor-air thermistor is faulty. Replace outdoor-air thermistor. Low suction pressure problem with a

compressor. IAQ is controlling minimum damper position. Adjust the IAQ settings if incorrect, otherwise,

Unit is in Unoccupied mode. Adjust unit occupied schedule if incorrect,

Unit is operating under free cooling. Economizer is operating correctly.

backwards. Economizer actuator is out of calibration or

spring return is backwards. Unit is operating under free cooling or a force is

applied to the commanded position.

Check wiring connections.

instructions. Adjust the high temperature lockout setting if it is

incorrect, otherwise, economizer is operating correctly.

Adjust the low temperature lockout setting if it is incorrect, otherwise, economizer is operating correctly.

Adjust the high temperature lockout setting if it is incorrect, otherwise, economizer is operating correctly.

Adjust the low temperature lockout setting if it is incorrect, otherwise, economizer is operating correctly.

Check enthalpy and return air compared to outside air temperature.

Economizer is operating correctly, identify compressor problem.

the economizer is operating correctly.

otherwise, economizer is operating correctly.

Identify the obstruction and safely remove.

Enter Service Test mode and run the Calibrate Economizer (E.CAL) procedure.

Economizer is operating correctly.

LEGEND

CCN — Carrier Comfort Network IAQ — Indoor Air Quality

Heating Troubleshooting

Use the unit scrolling marquee display or a CCN device to view the heating status display and the heating diagnostic display (see Appendix A) for information on the heating operation. Check the current alarms and alarm history for any heating alarm codes and correct any causes. (See Table 14.) Verify any unique control configurations per installed site requirements or accessories. If alarms conditions are corrected and

GAS HEAT (48HC UNITS) See Table 19 for general gas heating service analysis. See Fig. 17

for service analysis of the IGC board logic. Check the status LED on the IGC board for any flashing alarm codes and correct any causes. (See Table 20.)

ELECTRIC HEAT (50HC UNITS)

See Table 21 for electric heating service analysis. cleared, operation of the heat stages and indoor fan may be verified by using the Service Test mode. (See Table 6.)

Table 19 — Gas Heating Service Analysis

PROBLEM CAUSE REMEDY

Heat Will Not Turn On. Unit is NOT configured for heat. Check heating configurations using the

Burners Will Not Ignite. Active alarm. Check active alarms using ComfortLink scrolling

No power to unit. Check power supply, fuses, wiring, and circuit

No power to IGC (Integrated Gas Control). Check fuses and plugs. Heaters off due to time guard to prevent short

cycling. Thermostat or occupancy schedule set point not

calling for Cooling. No gas at main burners. Check gas line for air and purge as necessary.

Water in gas line. Drain water and install drip.

Inadequate Heating. Dirty air filters. Replace air filters.

Gas input too low. Check gas pressure at manifold. Refer to gas

Thermostat or occupancy schedule set point only calling for W1.

Unit undersized for load. Decrease load or increase of size of unit. Restricted airflow. Remove restriction. Check SAT compared to the

Too much outdoor air. Check economizer position and configuration.

Limit switch cycles main burners. Check rotation of blower, thermostat heat

Poor Flame Characteristics. Incomplete combustion (lack of combustion air)

Burners Will Not Turn Off. Unit is in Minimum on-time. Check using ComfortLink scrolling marquee and

results in: Aldehyde odors, CO, sooting flame, or floating flame.

Unit running in Service Test mode. Check using ComfortLink scrolling marquee. Main gas valve stuck. Turn off gas supply and unit power. Replace gas

ComfortLink scrolling marquee

marquee and the IGC flash codes.

breakers.

Check using ComfortLink scrolling marquee and the IGC flash codes.

Check using ComfortLink scrolling marquee.

After purging gas line of air, allow gas to dissipate for at least 5 minutes before attempting to re-light unit.

valve adjustment. Allow time for W2 to energize or adjust setpoints.

SAT heating limits.

Adjust minimum position using ComfortLink scrolling marquee.

anticipator settings, and temperature rise of unit. Adjust as needed.

Check all screws around flue outlets and burner compartment. Tighten as necessary.

Cracked heat exchanger, replace. Unit is over-fired, reduce input. Adjust gas line or

manifold pressure. Check vent for restriction. Clean as necessary. Check orifice to burner alignment.

the IGC flash codes.

valve.

1 FLASH - INDOOR FAN DELAY

MODIFIED (HEATING)

2 FLASHES - OPENING OF LIMIT

SWITCH

3 FLASHES - FLAME SENSOR

INDICATES FLAME WITH

CLOSED GAS VALVE

4 FLASHES - LIMIT SWITCH

CYCLED 4 TIMES ON SINGLE

CALL FOR HEAT

5 FLASHES - IGNITION LOCKOUT

(No ignition within 15 minutes)

6 FLASHES - INDUCED DRAFT

MOTOR FAULT

(No signal from the Hall Effect

Sensor or 60 seconds)

7 FLASHES - OPENING OF

ROLLOUT SWITCH

8 FLASHES - HARDWARE OR

SOFTWARE FAULT

9 FLASHES - SOFTWARE

LOCKOUT

FLASHING

LED is

CALL FOR

24 VOLTS

BETWEEN

F1 AND C

YES

DEFECTIVE IGC BOARD

1. BLOWN 5 AMP FUSE

2. DEFECTIVE 24V TRANS.

3. BROKEN WIRE

4. NO POWER TO UNIT

HEATING

‘W1’ FROM BASE CONTROL BOARD ENERGIZES ‘W’ ON IGC - 1 MINUTE LOCK-ON

COMBUSTION RELAY ON IGC IN ENERGIZED

COMBUSTION RELAY ENERGIZES INDUCED DRAFT MOTOR (IDM) THROUGH

TERMINAL ′CM′ ON IGC

IF IDM IS TURNING AT CORRECT SPEED (AT LEAST 2400 RPM), HALL

EFFECT SENSOR SENDS CORRECT SIGNAL TO TERMINAL ‘J1’ ON IGC

IF LIMIT SWITCH AND ROLLOUT

SWITCH ARE CLOSED, IGC SAFETY

LOGIC WILL INITIATE IGNITION

SEQUENCE

IGC HIGH VOLTAGE

TRANSFORMER CREATES A

10,000 VOLT SPARK FOR 5

SECONDS

IGC SAFETY LOGIC OPENS GAS

VALVE FOR 5 SECONDS

DOES IGC DETECT

.2 MICROAMPS FOR 2

SECONDS

Yes

AFTER 45 SECONDS (OR LESS IF THE TIMING

HAS BEEN REDUCED DUE TO LIMIT SWITCH

TRIPS) IGC WILL ENERGIZE BLOWER RELAY

DID LIMIT

SWITCH OPEN BEFORE THE 45

SECONDS (OR THE MODIFIED

TIME) HAS TIMED OUT?

Yes

IGC SAFETY LOGIC WILL SHUT

OFF GAS VALVE AND SPARK

20 SECOND PURGE OF HEAT

EXCHANGER

IS THIS THE

33RD RETRY? (OR 15

MINUTES)

Yes

IGNITION LOCKOUT

(5 FLASHES OF LED)

SUBTRACT 5 SECONDS (OR

ANOTHER 5 SECONDS) FROM

INDOOR FAN ON TIME DELAY

NORMAL HEATING OPERATION

HEATING DEMAND SATISFIED

45 SECOND BLOWER SHUTOFF DELAY

(DELAY EXTENDED BY 5 SECONDS FOR EACH LIMIT SWITCH TRIP

MAXIMUM DELAY: 3 MINUTES)

IDM STOPS, SAFETY LOGIC SHUTS OFF GAS VALVE

LEGEND

IDM – Induced-Draft Motor IGC – Integrated Gas Unit Controller

NOTE: Thermostat Fan Switch in the “AUTO” position.

OFF

Fig. 17 — IGC Service Analysis Logic

Table 20 — IGC Board LED Alarm Codes

LED FLASH

CODE

On Normal Operation — — —

Off Hardware Failure No gas heating. —

1 Flash

2 Flashes Limit Switch Fault

3 Flashes Flame Sense Fault Indoor fan and inducer On.

4 Flashes

5 Flashes Ignition Fault No gas heating.

6 Flashes Induced Draft Motor Fault

7 Flashes Rollout Switch Lockout

8 Flashes Internal Control Lockout No gas heating. Power reset.

9 Flashes

LEGEND

IGC — Integrated Gas Unit Control LED — Light-Emitting Diode

DESCRIPTION

Indoor Fan On/Off Delay Modified

Four Consecutive Limit Switch Fault

Temporary Software Lockout

ACTION TAKEN BY

CONTROL

5 seconds subtracted from On delay. 5 seconds added to Off delay (3 min max).

Gas valve and igniter Off. Indoor fan and inducer On.

No gas heating.

If heat off: no gas heating. If heat on: gas valve Off and inducer On.

Gas valve and igniter Off. Indoor fan and inducer On.

No gas heating.

RESET METHOD PROBABLE CAUSE

Power reset.

Limit switch closed, or heat call (W) Off.

Flame sense normal. Power reset for LED reset.

Heat call (W) Off. Power reset for LED reset.

Inducer sense normal, or heat call (W) Off.

Power reset.

1 hour auto reset, or power reset.

NOTES:

1. There is a 3-second pause between alarm code displays.

2. If more than one alarm code exists, all applicable alarm codes will be displayed in numerical sequence.

3. Alarm codes on the IGC will be lost if power to the unit is interrupted.

Loss of power to the IGC. Check 5 amp fuse on IGC, power to unit, 24V circuit breaker, transformer, and wiring to the IGC.

High temperature limit switch opens during heat exchanger warm-up period before fan-on delay expires. High temperature limit switch opens within 10 minutes of heat call (W) Off. See Limit Switch Fault.

High temperature limit switch is open. Check the operation of the indoor (evaporator) fan motor. Ensure that the supply-air temperature rise is within the range on the unit nameplate. Check wiring and limit switch operation.

The IGC sensed a flame when the gas valve should be closed. Check wiring, flame sensor, and gas valve operation.

4 consecutive limit switch faults within a single call for heat. See Limit Switch Fault.

Unit unsuccessfully attempted ignition for 15 minutes. Check igniter and flame sensor electrode spacing, gaps, etc. Check flame sense and igniter wiring. Check gas valve operation and gas supply.

Inducer sense On when heat call Off, or inducer sense Off when heat call On. Check wiring, voltage, and operation of IGC motor. Check speed sensor wiring to IGC.

Rollout switch has opened. Check gas valve operation. Check induced-draft blower wheel is properly secured to motor shaft.

IGC has sensed internal hardware or software error. If fault is not cleared by resetting 24 v power, replace the IGC.

Electrical interference is disrupting the IGC software.

Table 21 — Electric Heat Service Analysis

PROBLEM CAUSE REMEDY

Active alarm.

Unit is NOT configured for heat.

No power to unit.

Unit is in minimum heat off-time, or minimum cool-heat changeover time.

Heat Will Not Turn On.

Inadequate Heating.

Heat Will Not Turn Off.

Thermostat or occupancy schedule setpoint not calling for heating.

Heat forced off in Service Test mode.

No 24 vac at heater contactor.

Open temperature limit switch on heater.

Dirty air filters. Replace air filters. Thermostat or occupancy schedule setpoint only

calling for W1 Heat undersized for load. Decrease load or increase size of heater.

Restricted airflow

Too much outdoor air.

Limit switch cycles heaters. Check rotation of blower and minimum airflow.

Bad heater elements.

Unit is in minimum heat on-time. Check using ComfortLink scrolling marquee. Thermostat or occupancy schedule setpoint still

calling for heating.

Heat forced on in Service Test mode.

Heater contactor failed.

Phase Loss Protection

The phase loss protection option will monitor the three-phase electrical system to provide phase reversal and phase loss protection.

PHASE REVERSAL PROTECTION If the control senses an incorrect phase relationship, the relay

(K1) will be de-energized (opening its contact). If the phase relationship is correct, the relay will be energized. The control has a self-bypass function after a pre-set time. If the control determines that the three phases stay in a correct relationship for 10 consecutive minutes, the relay will stay energized regardless of the phase sequence of three inputs as long as 24-vac control voltage is applied. This self-bypass function will be reset if all three phases are restored in a phase loss event.

PHASE LOSS PROTECTION If the reverse rotation board senses any one of the three phase

inputs has no AC voltage, the relay will be de-energized (opening its contact). This protection is always active as long as 24vac control voltage is applied, and is not affected by the self by-pass function of the phase sequence monitoring function. However, in the event of phase loss, the relay will be re-energized only if all three phases are restored and the three phases are in the correct sequence.

A red LED is provided to indicate the function of the board. See the following table.

Check active alarms using ComfortLink scrolling marquee.

Check heating configurations using the ComfortLink scrolling marquee

Check power supply, fuses, wiring, and circuit breakers.

Check using ComfortLink scrolling marquee.

Check using ComfortLink scrolling marquee. Turn Service Test mode off.

Check transformer and circuit breaker. Check auto-reset limit switches on heater. Check manual-reset limit switch (LS) on indoor

fan housing. Check minimum airflow. Check limit switch when

it is cool, replace if open.

Allow time for W2 to energize or adjust setpoints.

Remove restriction. Check SAT compared to the SAT heating limits.

Check economizer position and configuration. Adjust minimum position.

Power off unit and remove high voltage wires. Check resistance of element, replace if open.

Check using ComfortLink scrolling marquee.

Check using ComfortLink scrolling marquee. Turn Service Test mode off.

Power off unit. Check contactor and replace if closed.

LED STATUS FUNCTION

On Continuously Relay contact closed (normal operation).

Blinking

Off 24 vac control power not present (off).

Relay contact open (phase loss or phase reversal has occurred) — No power will be supplied to the control system.

Thermistor Troubleshooting

The electronic control uses thermistors to sense temperatures used to control operation of the unit. Resistances at various temperatures are listed in Tables 22 and 23. Thermistor pin connection points are shown in the Major System Components section. The general locations of the thermistors are shown the Major System Components section.

AIR TEMPERATURES Air temperatures are measured with 10 kilo-ohm thermistors.

This includes supply-air temperature (SAT), outdoor-air temperature (OAT), space temperature sensors (T55, T56, T58), and return air temperature (RAT).

The supply air temperature (SAT) and outdoor air temperature (OAT) thermistors use a snap-mount to attach through the unit sheet metal panels. The snap-mount tabs must be flattened on the tip end of the sensor to release for removal from the panel. (See Fig. 18.) To reinstall, make sure the snap-mount tabs extend out.

Fig. 18 — SAT and OAT Thermistor Mounting

REFRIGERANT TEMPERATURES Condenser coil temperatures are measured with 5 kilo-ohm

thermistors. These measurements provide an approximate saturated condensing temperature for each circuit (SCT.A, SCT.B). Figures 19-23 show the factory locations for the SCT thermistors. Ensure that thermistors are placed at the correct location and are snapped securely over the return bend so that contact is made between the thermistor and the tube.

THERMISTOR/TEMPERATURE SENSOR CHECK A high quality digital volt-ohmmeter is required to perform

this check. Connect the digital voltmeter across the appropriate thermistor

terminals at the J8 terminal strip on the Main Base Board (see Major System Components on p. 68).

Using the voltage reading obtained, read the sensor temperature from Tables 22 and 23.

To check thermistor accuracy, measure temperature at probe location with an accurate thermocouple-type temperature-measuring instrument. Insulate thermocouple to avoid ambient temperatures from influencing reading. Temperature measured by thermocouple and temperature determined from thermistor voltage reading should be close, within 5°F if care was taken in applying thermocouple and taking readings.

If a more accurate check is required, unit must be shut down and thermistor removed and checked at a known temperature (freezing point or boiling point of water) using either voltage drop measured across thermistor at the J8 terminal, or by determining the resistance with unit shut down and thermistor disconnected from J8. Compare the values determined with the value read by the control in the Temperatures mode using the scrolling marquee display.

SENSOR TRIM Corrective offsets can be applied to the space temperature and

the supply air temperature sensor readings. These corrections are set in the Configuration in the MaintenanceTRIM table for CCN. See the Indoor Air Quality section for available adjustments to IAQ and OAQ sensor readings. The space temperature may be corrected by entering either a calibration temperature value in SPT.C, or an offset temperature value in SPT.T. The supply-air temperature may be corrected by entering either a calibration temperature value in SAT.C, or an offset temperature value in SAT.T. If in- stalled, the return air temperature may be corrected by entering either a calibration temperature value in RAT.C, or an offset temperature value in RAT.T. Temperature corrections should only be made if sensor readings are compared to an accurate reference temperature measurement device.



TRIM menu for the display, or

SCT.A

SCT.

48/50HC 04 SIZE

48/50HC 05, 06 SIZES

48/50HC 07 SIZE

Fig. 19 — Saturated Condensing Temperature Thermistor Location — 48/50HC 04-07

SCT. B

SCT. A

SCT. B

SCT. A

48/50HC 08, 09 SIZES

Fig. 20 — Saturated Condensing Temperature Thermistor Location — 48/50HC 08-12

SCT. B

SCT. ASCT. A

48/50HC 12 SIZE48/50HC 11 SIZE

SCT. B

SCT. A

CIRCUIT “B”

CIRCUIT “A”

Fig. 21 — Saturated Condensing Temperature Thermistor Location — 48/50HC 14

Fig. 22 — Saturated Condensing Temperature Thermistor Location — 48/50HC 17-20

SCT.B

SCT.A

SCT.B

Fig. 23 — Saturated Condensing Temperature Thermistor Location — 48/50HC 24-28

Transducer Troubleshooting

The electronic control uses suction pressure transducers to measure the suction pressure of the refrigerant circuits. The pressure/voltage characteristics of these transducers are in shown in Table 24, the 5vdc power is applied to legs A and B of the transducer and legs B to C represent the signal voltage. To use the voltage drop table for troubleshooting, read the voltage across A and B, then subtract the voltage reading from B to C. This is the voltage drop which can be looked up in Table 24. The accuracy of these transducers can be verified by connecting an accurate pressure gauge to the second refrigerant port in the suction line.

Forcing Inputs and Outputs

Many variables may have their value forced through CCN or directly at the local display. This can be useful during diagnostic testing and also during operation, typically as part of an advanced third party control scheme. Input and output points that may be forced are indicated as ‘forcible’ in the write status column of the display and CCN tables.

If the user needs to force a variable, follow the same process as when editing a configuration parameter. A forced variable will be displayed on the scrolling marquee with a blinking period “.” following its value. A forced value on Navigator accessory is indicated with a blinking “f”. A forced value on CCN devices is indicated with “Control” if forced at the unit display, or “Supervisor” if forced via CCN. To remove a local force with the scrolling marquee, select the point with the ENTER key and then press the up-arrow and down-arrow keys simultaneously.

NOTE: In the case of a control power reset, any force in effect at the time of power reset will be cleared.

Table 22 — Temperature (°F) vs Resistance/Voltage Drop Values for OAT, SAT, and SPT Thermistors (10K at

25°C Type II Resistors)

TEMP (F)

–25 196,453 4.758 59 3.056 1 5,714 143 2,343 0.949 –24 189,692 4.750 60 3.025 1 5,317 144 2,297 0.934 –23 183,300 4.741 61 2.994 1 4,925 145 2,253 0.919 –22 177,000 4.733 62 2.963 1 4,549 146 2,209 0.905 –21 171,079 4.724 63 2.932 1 4,180 147 2,166 0.890 –20 165,238 4.715 64 2.901 1 3,824 148 2,124 0.876 –19 159,717 4.705 65 2.870 1 3,478 149 2,083 0.862 –18 154,344 4.696 66 2.839 1 3,139 150 2,043 0.848 –17 149,194 4.686 67 2.808 1 2,814 151 2,003 0.835 –16 144,250 4.676 68 2.777 1 2,493 152 1,966 0.821 –15 139,443 4.665 69 2.746 1 2,187 153 1,928 0.808 –14 134,891 4.655 70 2.715 1 1,884 154 1,891 0.795 –13 130,402 4.644 71 2.684 1 1,593 155 1,855 0.782 –12 126,183 4.633 72 2.653 1 1,308 156 1,820 0.770 –11 122,018 4.621 73 2.622 1 1,031 157 1,786 0.758 –10 118,076 4.609 74 2.592 1 0,764 158 1,752 0.745

–9 114,236 4.597 75 2.561 1 0,501 159 1,719 0.733 –8 110,549 4.585 76 2.530 1 0,249 160 1,687 0.722 –7 107,006 4.572 77 2.500 1 0,000 161 1,656 0.710 –6 103,558 4.560 78 2.470 9,762 162 1,625 0.699 –5 100,287 4.546 79 2.439 9,526 163 1,594 0.687 –4 97,060 4.533 80 2.409 9,300 164 1,565 0.676 –3 94,020 4.519 81 2.379 9,078 165 1,536 0.666 –2 91,019 4.505 82 2.349 8,862 166 1,508 0.655 –1 88,171 4.490 83 2.319 8,653 167 1,480 0.645

0 85,396 4.476 84 2.290 8,448 168 1,453 0.634 1 82,729 4.461 85 2.260 8,251 169 1,426 0.624 2 80,162 4.445 86 2.231 8,056 170 1,400 0.614 3 77,662 4.429 87 2.202 7,869 171 1,375 0.604 4 75,286 4.413 88 2.173 7,685 172 1,350 0.595 5 72,940 4.397 89 2.144 7,507 173 1,326 0.585 6 70,727 4.380 90 2.115 7,333 174 1,302 0.576 7 68,542 4.363 91 2.087 7,165 175 1,278 0.567 8 66,465 4.346 92 2.059 6,999 176 1,255 0.558

9 64,439 4.328 93 2.030 6,838 177 1,233 0.549 10 62,491 4.310 94 2.003 6,683 178 1,211 0.540 11 60,612 4.292 95 1.975 6,530 179 1,190 0.532 12 58,781 4.273 96 1.948 6,383 180 1,169 0.523 13 57,039 4.254 97 1.921 6,238 181 1,148 0.515 14 55,319 4.235 98 1.894 6,098 182 1,128 0.507 15 53,693 4.215 99 1.867 5,961 183 1,108 0.499 16 52,086 4.195 100 1.841 5,827 184 1,089 0.491 17 50,557 4.174 101 1.815 5,698 185 1,070 0.483 18 49,065 4.153 102 1.789 5,571 186 1,052 0.476 19 47,627 4.132 103 1.763 5,449 187 1,033 0.468 20 46,240 4.111 104 1.738 5,327 188 1,016 0.461 21 44,888 4.089 105 1.713 5,210 189 998 0.454 22 43,598 4.067 106 1.688 5,095 190 981 0.447 23 42,324 4.044 107 1.663 4,984 191 964 0.440 24 41,118 4.021 108 1.639 4,876 192 947 0.433 25 39,926 3.998 109 1.615 4,769 193 931 0.426 26 38,790 3.975 110 1.591 4,666 194 915 0.419 27 37,681 3.951 111 1.567 4,564 195 900 0.413 28 36,610 3.927 112 1.544 4,467 196 885 0.407 29 35,577 3.903 113 1.521 4,370 197 870 0.400 30 34,569 3.878 114 1.498 4,277 198 855 0.394 31 33,606 3.853 115 1.475 4.185 199 841 0.388 32 32,654 3.828 116 1.453 4,096 200 827 0.382 33 31,752 3.802 117 1.431 4,008 201 814 0.376 34 30,860 3.776 118 1.409 3,923 202 800 0.370 35 30,009 3.750 119 1.387 3,840 203 787 0.365 36 29,177 3.723 120 1.366 3,759 204 774 0.359 37 28,373 3.697 121 1.345 3,681 205 762 0.354 38 27,597 3.670 122 1.324 3,603 206 749 0.349 39 26,838 3.654 123 1.304 3,529 207 40 26,113 3.615 124 1.284 3,455 208 725 0.338 41 25,396 3.587 125 1.264 3,383 209 714 0.333 42 24,715 3.559 126 1.244 3,313 210 702 0.328 43 24,042 3.531 127 1.225 3,244 211 691 0.323 44 23,399 3.503 128 1.206 3,178 212 680 0.318 45 22,770 3.474 129 1.187 3,112 213 670 0.314 46 22,161 3.445 130 1.168 3,049 214 659 0.309 47 21,573 3.416 131 1.150 2,986 215 649 0.305 48 20,998 3.387 132 1.132 2,926 216 639 0.300 49 20,447 3.357 133 1.114 2,866 217 629 0.296 50 19,903 3.328 134 1.096 2,809 218 620 0.292 51 19,386 3.298 135 1.079 2,752 219 610 0.288 52 18,874 3.268 136 1.062 2,697 220 601 0.284 53 18,384 3.238 137 1.045 2,643 221 592 0.279 54 17,904 3.208 138 1.028 2,590 222 583 0.275 55 17,441 3.178 139 1.012 2,539 223 574 0.272 56 16,991 3.147 140 0.996 2,488 57 16,552 3.117 141 0.980 2,439 225 557 0.264 58 16,131 3.086 142 0.965 2,391

RESISTANCE

(Ohms)

VOLTAGE DROP (V)

TEMP (F)

RESISTANCE

(Ohms)

VOLTAGE

DROP (V)

TEMP (F)

224 566 0.268

RESISTANCE

(Ohms)

737 0.343

VOLTAGE

DROP (V)

Table 23 — Temperature (°F) vs. Resistance/Voltage Drop Values for SCT Sensors (5K at 25°C Resistors)

TEMP (F)

–25 3.699 98,010 59 1.982 7,866 143 1,190 0.511 –24 3.689 94,707 60 1.956 7,665 144 1,165 0.502 –23 3.679 91,522 61 1.930 7,468 145 1,141 0.494 –22 3.668 88,449 62 1.905 7,277 146 1,118 0.485 –21 3.658 85,486 63 1.879 7,091 147 1,095 0.477 –20 3.647 82,627 64 1.854 6,911 148 1,072 0.469 –19 3.636 79,871 65 1.829 6,735 149 1,050 0.461 –18 3.624 77,212 66 1.804 6,564 150 1,029 0.453 –17 3.613 74,648 67 1.779 6,399 151 1,007 0.445 –16 3.601 72,175 68 1.754 6,238 152 986 0.438 –15 3.588 69,790 69 1.729 6,081 153 965 0.430 –14 3.576 67,490 70 1.705 5,929 154 945 0.423 –13 3.563 65,272 71 1.681 5,781 155 925 0.416 –12 3.550 63,133 72 1.656 5,637 156 906 0.408 –11 3.536 61,070 73 1.632 5,497 157 887 0.402 –10 3.523 59,081 74 1.609 5,361 158 868 0.395

–9 3.509 57,1 62 75 1.585 5,229 159 850 0.388 –8 3.494 55,3 11 76 1.562 5,101 160 832 0.381 –7 3.480 53,5 26 77 1.538 4,976 161 815 0.375 –6 3.465 51,8 04 78 1.516 4,855 162 798 0.369 –5 3.450 50,1 43 79 1.493 4,737 163 782 0.362 –4 3.434 48,5 41 80 1.470 4,622 164 765 0.356 –3 3.418 46,9 96 81 1.448 4,511 165 750 0.350 –2 3.402 45,5 05 82 1.426 4,403 166 734 0.344 –1 3.386 44,0 66 83 1.404 4,298 167 719 0.339

0 3.369 42,679 84 1.382 4,196 168 705 0.333 1 3.352 41,339 85 1.361 4,096 169 690 0.327 2 3.335 40,047 86 1.340 4,000 170 677 0.322 3 3.317 38,800 87 1.319 3,906 171 663 0.317 4 3.299 37,596 88 1.298 3,814 172 650 0.311 5 3.281 36,435 89 1.278 3,726 173 638 0.306 6 3.262 35,313 90 1.257 3,640 174 626 0.301 7 3.243 34,231 91 1.237 3,556 175 614 0.296 8 3.224 33,185 92 1.217 3,474 176 602 0.291

9 3.205 32,176 93 1.198 3,395 177 591 0.286 10 3.185 31,2 02 94 1.179 3,318 178 581 0.282 11 3.165 30,2 60 95 1.160 3,243 179 570 0.277 12 3.145 29,3 51 96 1.141 3,170 180 561 0.272 13 3.124 28,4 73 97 1.122 3,099 181 551 0.268 14 3.103 27,6 24 98 1.104 3,031 182 542 0.264 15 3.082 26,8 04 99 1.086 2,964 183 533 0.259 16 3.060 26,0 11 100 1.068 2,898 184 524 0.255 17 3.038 25,2 45 101 1.051 2,835 185 516 0.251 18 3.016 24,5 05 102 1.033 2,773 186 508 0.247 19 2.994 23,7 89 103 1.016 2,713 187 501 0.243 20 2.972 23,0 96 104 0.999 2,655 188 494 0.239 21 2.949 22,4 27 105 0.983 2,597 189 487 0.235 22 2.926 21,7 79 106 0.966 2,542 190 480 0.231 23 2.903 21,1 53 107 0.950 2,488 191 473 0.228 24 2.879 20,5 47 108 0.934 2,436 192 467 0.224 25 2.856 19,9 60 109 0.918 2,385 193 461 0.220 26 2.832 19,3 93 110 0.903 2,335 194 456 0.217 27 2.808 18,8 43 111 0.888 2,286 195 450 0.213 28 2.784 18,3 11 112 0.873 2,239 196 445 0.210 29 2.759 17,7 96 113 0.858 2,192 197 439 0.206 30 2.735 17,2 97 114 0.843 2,147 198 434 0.203 31 2.710 16,8 14 115 0.829 2,103 199 429 0.200 32 2.685 16,3 46 116 0.815 2,060 200 424 0.197 33 2.660 15,8 92 117 0.801 2,018 201 419 0.194 34 2.634 15,4 53 118 0.787 1,977 202 415 0.191 35 2.609 15,0 27 119 0.774 1,937 203 410 0.188 36 2.583 14,6 14 120 0.761 1,898 204 405 0.185 37 2.558 14,2 14 121 0.748 1,860 205 401 0.182 38 2.532 13,8 26 122 0.735 1,822 206 396 0.179 39 2.506 13,4 49 123 0.723 1,786 207 40 2.480 13,0 84 124 0.710 1,750 208 386 0.173 41 2.454 12,7 30 125 0.698 1,715 209 382 0.171 42 2.428 12,3 87 126 0.686 1,680 210 377 0.168 43 2.402 12,0 53 127 0.674 1,647 211 372 0.165 44 2.376 11,7 30 128 0.663 1,614 212 367 0.163 45 2.349 11,4 16 129 0.651 1,582 213 361 0.160 46 2.323 11,1 12 130 0.640 1,550 214 356 0.158 47 2.296 10,8 16 131 0.629 1,519 215 350 0.155 48 2.270 10,5 29 132 0.618 1,489 216 344 0.153 49 2.244 10,2 50 133 0.608 1,459 217 338 0.151 50 2.217 9,979 134 0.597 1,430 218 332 0.148 51 2.191 9,717 135 0.587 1,401 219 325 0.146 52 2.165 9,461 136 0.577 1,373 220 318 0.144 53 2.138 9,213 137 0.567 1,345 221 311 0.142 54 2.112 8,973 138 0.557 1,318 222 304 0.140 55 2.086 8,739 139 0.548 1,291 223 297 0.138 56 2.060 8,511 140 0.538 1,265 224 289 0.135 57 2.034 8,291 141 0.529 1,240 225 282 0.133 58 2.008 8,076 142 0.520 1,214

RESISTANCE

(Ohms)

VOLTAGE DROP

(V)

TEMP (F)

RESISTANCE

(Ohms)

VOLTAGE DROP

(V)

TEMP (F)

RESISTANCE

(Ohms)

391 0.176

VOLTAGE DROP

(V)

Table 24 — Pressure (psig) vs Voltage Drop Values for Suction Pressure Transducers

PRESSURE

(psi

0 0.465 68 1.135 136 1.804 204 2.474 2 0.485 70 1.154 138 1.824 206 2.493 4 0.505 72 1.174 140 1.844 208 2.513 6 0.524 74 1.194 142 1.863 210 2.533

8 0.544 76 1.214 144 1.883 212 2.553 10 0.564 78 1.233 146 1.903 214 2.572 12 0.583 80 1.253 148 1.922 216 2.592 14 0.603 82 1.273 150 1.942 218 2.612 16 0.623 84 1.292 152 1.962 220 2.631 18 0.642 86 1.312 154 1.982 222 2.651 20 0.662 88 1.332 156 2.001 224 2.671 22 0.682 90 1.351 158 2.021 226 2.690 24 0.702 92 1.371 160 2.041 228 2.71 26 0.721 94 1.391 162 2.060 230 2.730 28 0.741 96 1.410 164 2.080 232 2.749 30 0.761 98 1.430 166 2.100 234 2.769 32 0.780 100 1.450 168 2.119 236 2.789 34 0.800 102 1.470 170 2.139 238 2.809 36 0.820 104 1.489 172 2.159 240 2.828 38 0.839 106 1.509 174 2.178 242 2.848 40 0.859 108 1.529 176 2.198 244 2.868 42 0.879 110 1.548 178 2.218 246 2.887 44 0.898 112 1.568 180 2.237 248 2.907 46 0.918 114 1.588 182 2.257 250 2.927 48 0.938 116 1.607 184 2.277 252 2.946 50 0.958 118 1.62 52 0.977 120 1.647 188 2.316 256 2.986 54 0.997 122 1.666 190 2.336 258 3.005 56 1.017 124 1.686 192 2.356 260 3.025 58 1.036 126 1.706 194 2.375 262 3.045 60 1.056 128 1.726 196 2.395 264 3.065 62 1.076 130 1.745 198 2.415 266 3.084 64 1.095 132 1.765 200 2.434 268 3.104 66 1.115 134 1.785 202 2.454 270 3.124

VOLTAGE DROP (V

)

PRESSURE

(psi

VOLTAGE DROP (V

)

7 186 2.297 254 2.966

PRESSURE

(psi

VOLTAGE DROP (V

)

PRESSURE

(psi

VOLTAGE DROP (V

)

Troubleshooting Units Equipped with EnergyX System

COMPLETE ERV STOPPAGE EnergyX

an integrated ERV. The ERV requires communication from the rooftop for operation. This section covers ERV troubleshooting only. For rooftop troubleshooting refer to the base unit’s Service manual.

Complete ERV Stoppage There are several conditions that can cause the ERV to shut-

down or appear to be shutdown:

• General power failure.

• Transformer’s circuit breaker tripped.

• ERV main power fuses blown.

• Communication failures.

• Active alarm on the base rooftop unit or the ERV prevent-

• Programmed occupancy schedule. Rooftop Unoccupied

• Rooftop indoor fan is off.

• The airflow sensor tubing connected to the incorrect high/

CHECK ALARMS The ERV has 4 possible alarms based on options installed in

the ERV. These alarms are described in detail below. They all

units are a combination of the base rooftop unit and

ing operation. Review alarms.

low sensor ports in the outside air.

show up as a T418 alarm in the ComfortLink controller. Pressing enter and escape together on the scrolling marquee or Navigator display will expand the text and provide the specific alarm condition. There are 4 status points viewed under Operating Modes on the scrolling marquee or Navigator display (Operating Modes

→OAU) for each alarm to help diagnose

which alarm caused the T418 in the ComfortLink controller. These will all reset automatically when the situation has been resolved.

T418 OAU Filter Dirty

The ERV’s dirty filter alarm should only occur if the optional Filter Maintenance Switch is installed on the ERV. The dirty filter alarm activates due to an increase in differential pressure across the filters. The EXCB’s D16 LED will be turn on and the OAU Dirty Filter Alarm point will be turned to on (Operat-

ing Modes

fect unit operation but serves as a warning to replace the filters. It will automatically reset when the pressure differential falls below setpoint. Verify proper operation by partially blocking airflow through the ERV filters and confirming that the alarm does trip.

T418 OAU MOTOR FAILURE This alarm indicates a motor problem in the ERV, any one of

the motors can trip this alarm (outside intake, exhaust and/or the wheel motor). The intake and exhaust motors have build in motor diagnostics and the wheel motor status is a field accessory. Since these are feed into the same alarm, it is important to

→OAU →ALM.2 = On). The alarm does not af-

determine which one is having the problem. In test mode run the components individually to determine which is causing the problem. If the Shut Down on fan failure configuration is set to Yes ( Configuration

→OAU →OAU.F = Yes), the ERV will

shutdown with this alarm active. If set to no, the ERV will continue to run as if the alarm did not occur, outside air CFM, exhaust CFM, or pre-conditions might not be achievable if a motor fails. The two classes of motor status are explained below.

Intake and Exhaust Motor Status

If any one of the ERV’s outside or exhaust motors detects a problem, it will close its build in normally open alarm contact, which will be seen as 24vac at EXCB J8-3. The EXCB’s D18 LED will be turn on and the OAU Motor Failure Alarm point will be turned to on (Operating Modes

→OAU →ALM.1 =

On). This alarm will automatically reset when the motor opens its alarm relay. This alarm is tripped by one of the following: phase loss, locked rotor, thermal overload, communication error, incorrect signal, or a fan failure.

Wheel Status

This alarm will occur when the ERV wheel is turned on and the wheel proxy sensor does not detect wheel motion within the set time. It will open its contact which energizes the normally closed rotation monitor relay. This is seen as 24vac at EXCB J5-3 and causes the alarm. The EXCB’s D12 LED will be turned on and the OAU Motor Failure Alarm point will be turned to on (Operating Modes

→OAU →ALM.1 = On).

This alarm will automatically reset when motion is detected. Possible causes of this alarm are: the wheel belt breaking or slipping, wheel motor failure, proxy sensor failure or incorrect setting, or wiring error.

T418 OAU LOW CFM This alarm indicates that the ERV cannot bring in the desired

amount of outside air. The alarm occurs when the actual outside air CFM (Operating Modes

→OAU →A.OA) is less than

10% of the commanded outside air CFM (Operating Modes

→OAU →C.OA) after 10 minutes. This alarm will not occur

in test mode or defrost mode. The Rooftop unit might be able to help by ramping its indoor fan up. Refer to the base controls, start up, operation, and troubleshooting manual for details. The OAU Low CFM Alarm point will be turned to on (Operating

Modes

→OAU →ALM.3 = On). This alarm will automatical-

ly reset if the actual CFM is within 10% of the commanded CFM. Possible causes of this are: outside air CFM setpoint set too high, dirty filter or plugged screen, pressure tubing wrong or disconnected, wrong OA CFM curve programmed, or RTU indoor fan speed running too low.

T418 OAU GENERAL ALARM This alarm is not currently used by the ERV.

Check Diagnostic LEDs

Use the on board LEDs to assist in troubleshooting the EnergyX

® system. The EnergyX Control Board (EXCB) and the

Universal Protocol Converter (UPC) each have LEDs that can help in the troubleshooting process. See Tables 25-27.

The EXCB has five green LEDs and one red LED. The red LED is for power indication and the green LEDs are status indicators.

The UPC has seven LEDs. There are four communication LEDs and three status LEDs. The communication LEDs indicate if the translator is speaking to the devices on the network and should reflect communication traffic based on the baud rate set. The higher the baud rate, the LEDs would become more solid.

Table 25 — EXCB LED Indicators

LED COLOR DESCRIPTION

D9 Red 24vAC board power Board has power D2 Green Run light Flashing ERV is Running

D12 Green ERV Wheel Status Alarm

D14 Green

D16 Green ERV Dirty Filter Alarm Dirty Filter D18 Green ERV Blower Status Alarm Fan Failure

ERV Wheel Frost Protection

STATUS IF LIGHT IS LIT

ERV Wheel not rotating when it should be

ERV detects frost on the wheel and running in Frost Mode

Table 26 — EXUPC LED Indicators

LED COLOR DESCRIPTION STATUS IF LIGHT IS LIT

Power Green Power Indicator

Rx1 Green

Rx2 Green

Tx1 Green

Tx2 Green

Run Green Run indicator

Error Red

* Modbus is a registered trademark of Schneider Electric.

Port 1 Receiving Data

Port 2 Receiving Data

Port 1 Transmitting Data

Port 2 Transmitting Data

Internal Error indicator

Lights when power is being supplied to the translator.

Lights when the translator receives data from ComfortLink MBB via LEN

Lights when the translator receives data from the Modbus* EXCB

Lights when the translator transmits data to the ComfortLink MBB via LEN

Lights when the translator transmits data to the Modbus EXCB

Lights based on translator health. See Table 27.

Lights based on translator health, See Table 27.

Table 27 — EXUPC LED Flash Code Diagnostics

Run LED Status

2 flashes per second

5 flashes per second

7 flashes per second

14 flashes per second

Alternating with Error

Error LED Status

Off Normal 2 flashes,

alternating with Run LED

3 flashes then off

4 flashes then pause

1 flash per second

Off

7 flashes per second, alternating with Run LED

14 flashes per second, alternating with Run LED

Alternating with Run

ERV Module Status

5 minute auto - restart delay after system error

Module has just been formatted

Two or more devices on this network have the same ARC156 network address

Module is alone on the network

Operation halted after frequent system errors or control programs halted

Operation start - up aborted. Boot is running

Firmware transfer in progress. Boot is running

Ten second recovery period after brownout

Brownout

Restoring memory from Archive

Communication Failures

Communication is critical for ERV operation. It can fail on two different paths; between the UPC and the rooftop (LEN), or between the UPC and the EXCB. This makes the UPC critical to ERV operation. Make sure the UPC DIP switches and rotary switches are set correctly. Make sure the board hardware jumpers are set on EIA 485 and 2W. During normal operation the 4 communication LEDs will flash interchangeably. If all 4 LEDs are not flashing then there is a communication problem. Check connections between Port 1a and rooftop’s LEN connection and Port 2 and the EXCB J23 (verify with the proper unit schematic).

The ERVs, LCD screen will show specific communication failures when they occur. Use the LCD screen to help troubleshoot communications failures. If communication is established, the LED shows “communication connected”.

COMM FAILURE1 – UPC TO LEN FAIL This will be displayed if the EXCB can communicate with the

UPC, but the UPC does not receive information from the Com- fortLink controller. This will occur if the cable is pinched or disconnected, wired wrong or loose, or if the UPC is configured wrong.

COMM FAILURE2 – UPC TO EXCB FAIL This will be displayed if the EXCB cannot communicate with

the UPC. This will occur if the connection between them is disconnected or pinched. This will also occur if the UPC does not have power or software, or if it has an error or configured wrong.

On-Board Pressure Transducers

The EXCB uses on-board pressure transducers to measure the air pressure of the incoming outside air and the building exhaust air. The CFM values are then calculated based on these readings and the fan speed. There is a pressure transducer for the outside air and one for the exhaust air. These are screwed

into the EXCB board to J24 and J25 respectively. They have three pins: IN, GND, and OUT. The IN pin is 5vdc input power and GND is the common or ground pin. The OUT pin will be

0.26 to 4.5vdc based on the pressure reading. There are two different transducers used, two inch of water column (in.wg) and 5 in.wg. Table 28 shows the voltage/pressure characteristics of each.

Table 28 — Transducer/Voltage vs. Pressure

Voltage (vDC)

<= –0.26 0.00 0.00

0.5 0.12 0.28

1.0 0.34 0.87

1.5 0.53 1.46

2.0 0.82 2.05

2.5 1.06 2.64

3.0 1.30 3.23

3.5 1.52 3.82

4.0 1.76 4.41

4.5 2.00 5.00

2 in. transducer 5 in. transducer

Pressure (in.wg)

MAJOR SYSTEM COMPONENTS

General

The 48/50HC single package rooftop units contain the ComfortLink electronic control system that monitors all operations of

the rooftop. The control system is composed of several main control components and available factory-installed options or field-installed accessories as listed in sections below. See Figs. 24-31 for typical control and power schematics for 48HC and 50HC. Refer to the base unit installation instructions or actual unit control box for specific unit wiring diagrams.

Fig. 24 — Typical Control Diagram for 48HC 04-14 Units (48HC 08-09 shown)

Fig. 25 — Typical Power Diagram for 48HC 04-14 Units (48HC 08-09 shown)

Fig. 26 — Typical Control Diagram for 50HC 04-14 Units (50HC 14 shown)

Fig. 27 — Typical Power Diagram for 50HC 04-14 Units (50HC 14 Non-Humidi-MiZer shown)

Fig. 28 — Typical Control Diagram 48HC 17-28 Units

Fig. 29 — Typical Control Diagram 50HC 17-28 Units

Fig. 30 — Typical Humid-MiZer Power Diagram and Component Arrangement 48/50HC 17-28 Units

Fig. 31 — Typical Non-Humid-MiZer Power Diagram and Component Arrangement 48/50HC 17-28 Units

Main Base Board (MBB)

CEPL130346-01

STATU S

LEN

J10

CCN

RED LED - STATU S GREEN LED -

LEN (LOCAL EQUIPMENT NETWORK)

YELLOW LED CCN (CARRIER COMFORT NETWORK)

INSTANCE JUMPER (SET TO 1)

See Fig. 32 and Table 29. The MBB is the center of the ComfortLink control system. It contains the major portion of the

operating software and controls the operation of the unit. The MBB continuously monitors input/output channel information received from its inputs and from the Economizer Control Board (ECB). The MBB receives inputs from thermistors and transducers. The MBB also receives the Current Sensor inputs

for compressors and other discrete or digital inputs. The MBB reads space temperature (SPT) from either a T-55, T-56 or T-58 device and space temperature offset (SPTO) from a T-56 device. See Field-Installed Accessories section. The MBB controls 11 relays.

NOTE: The Main Base Board (MBB) has a 3-position instance jumper that is factory set to ‘1.’ Do not change this setting.

Fig. 32 — Main Base Board (MBB)

Table 29 — Main Base Board (MBB) Connections

DISPLAY NAME POINT DESCRIPTION SENSOR LOCATION TYPE OF I/O

INPUTS

Input power from TRAN2 control box 24 VAC J1, 1-3

IGC.F IGC Fan Request gas section switch input J6, 4 FDWN Fire shutdown switch supply/return/space switch input J6, 6 G Thermostat G (Fan) space switch input J7, 2 W2 Thermostat W2 (2nd Stage Heat) space switch input J7, 4 W1 Thermostat W1 (1st Stage Heat) space switch input J7, 6 Y2 Thermostat Y2 (2nd Stage Cool) space switch input J7, 8 Y1 Thermostat Y1 (1st Stage Cool) space switch input J7, 10 FIL.S Filter status switch indoor fan section switch input J9, 2-3 HUM Humidistat switch input space switch input J9, 5-6

Not Used 0-5vdc digital input J9, 7-9 Not Used 0-5vdc digital input J9, 10-12

SPT Space temperature (T55/56) space 10k thermistor J8, 1-2 SPTO Space temperature offset (T56) space 10k thermistor J8, 2-3 OAT Outdoor air temperature outdoor coil support 10k thermistor J8, 5-6

SAT Supply air temperature

SCT.A

SCT.B

RAT Return Air Temperature

FAN.S Fan status switch

SSP.A Suction pressure, circuit A compressor A suction pipe

SSP.B Suction pressure, circuit B compressor B suction pipe

OUTPUTS CRC Cooling Reheat Control relay J10, 3 RH2.A Reheat 2 Valve Circuit A relay J10, 6 RH2.B Reheat 2 Valve circuit B relay J10, 9 IDF.1 Indoor fan relay 1 relay J10, 11 IDF.2 Indoor Fan relay 2 relay J10, 13 IDF.3 Indoor Fan relay 3 relay J10, 16 ALRM Alarm relay relay J10, 19 COMP.B Compressor B1 relay relay J10, 21 COMP.A Compressor A1 relay relay J10, 23 HT.1 Heat Stage 2 relay relay J10, 25 HT.2 Heat Stage 1 relay relay J10, 27 COMMUNICATION

Saturated condenser temperature, circuit A

Saturated condenser temperature, circuit B

Return 10k thermistor J8, 13-14

indoor fan section switch input J8, 15-16

Not Used 0-5 VDC J8, 24-26

Local Equipment Network (LEN) communication J5, 1-3 Carrier Comfort Network (CCN) communication J5, 5-7 Network device power 24 VAC J5, 9-10 Scrolling Marquee Display (LEN) communication J4, 1-3 Scrolling Marquee Display power 24 VAC J4, 5-6 Expansion LEN Bus communication J3, 1-3 Optional ECB power 24 VAC J2, 1-2

indoor fan housing, or

supply duct

outdoor coil, circuit A 5k thermistor J8, 9-10

outdoor coil, circuit B 5k thermistor J8, 11-12

10k thermistor J8, 7-8

0-5 VDC pressure

transducer

0-5 VDC pressure

transducer

CONNECTION PIN

NUMBER

J8, 18-20

J8, 21-23

Economizer Control Board (ECB)

The ECB controls the economizer actuator. (See Fig. 33 and Table 30.) The control signal from the ECB uses either the MFT (Multi-Function Technology) digital communication protocol or a 4 to 20 mA output signal as defined by the configuration Configuration Indoor Air Quality (IAQ), Outdoor Air Quality (OAQ), enthalpy and RH sensor. It also controls two power exhaust outputs.



ECONE.CTL. The ECB has inputs for

By digitally communicating with the ECB, the economizer actuator is able to provide the damper position and diagnostic information to the ComfortLink controller. The damper position is displayed at Outputs



ECONEC.AP. Diagnostic informa-

tion is displayed via Alert T414. More information about these alarms is contained in the Alarms and Alerts section.

NOTE: The Economizer Control Board (ECB) has a 4-position DIP switch that is factory set to ‘0’ (ON, towards the center of the board). Do not change this setting.

Fig. 33 — Economizer Control Board (ECB)

Table 30 — Economizer Control Board (ECB) Connections

DISPLAY NAME POINT DESCRIPTION SENSOR LOCATION TYPE OF I/O

INPUTS

Input power from MBB control box 24 VAC J1, 1- 2

RM.OC Remote occupancy switch field installed switch input J4, 2

ENTH or IAQ.S

IAQ Indoor air quality sensor return/space 0-20 mA J5, 2

OAQ or SP.RH

OUTPUTS

PE.1 Power exhaust 1 relay relay J8, 3 PE.2 Power exhaust 2 relay relay J8, 6 EC.CP Commanded Economizer position 0-20 mA J9, 1 COMMUNICATION

EC.CP & EC.AP

Outdoor enthalpy switch, or Indoor air quality switch

Outdoor air quality sensor, or Relative humidity sensor

Sensor Common Ground J5, 3 Actuator Common Ground J7, 3

Output power to enthalpy switch 24 VAC J4, 3 Output power for loop power sensors 24 VDC J5, 1 Output power to economizer actuator 24 VAC J7, 2

Local Equipment Network (LEN) communication J2, 1-3 Carrier Comfort Network (CCN) communication J3 Economizer actuator position (digital

control)

economizer, or return/space switch input J4, 4

field installed 0-20 mA J5, 5

MFT communication J7, 1

CONNECTION PIN

NUMBER

Integrated Gas Control (IGC) Board

RED LED-STAT US

The IGC is provided on gas heat units. (See Fig. 34 and Table 31.) The IGC controls the direct spark ignition system and monitors

the rollout switch, limit switch, and induced-draft motor Hall Effect switch.

Fig. 34 — Integrated Gas Control (IGC) Board

Table 31 — Integrated Gas Control (IGC) Board Connections

TERMINAL LABEL POINT DESCRIPTION SENSOR LOCATION TYPE OF I/O

INPUTS RT, C Power for IDR on 575v units control box 24 VAC Spade C Input power common Spade SS Speed sensor gas section analog input J1, 1- 3 FS, T1 Flame sensor gas section switch input Spade W Heat stage 1 Call MBB to CTB to IGC 24 VAC J2, 2 G Indoor Fan Call CTB to IGC 24 VAC J2, 3 R Input power from TRAN 1 CTB to IGC 24 VAC J2, 4 RS Rollout switch gas section switch input J2, 5-6 LS Limit switch gas section switch input J2, 7-8 CS Centrifugal switch (not used) switch input J2, 9-10 OUTPUTS L1, CM Induced draft combustion motor or relay gas section line VAC IFO Indoor fan request control box relay J2, 1 GV (W1) Gas valve (heat stage 1) gas section relay J2, 12 GV (W2) Gas Valve (heat stage 2, from CTB) gas section Not on IGC

CONNECTION PIN

NUMBER

48/50HC 04-14 Units — Low Voltage Terminal Board (TB)

The field connection terminal board has 30 terminals oriented in 3 rows of 10 terminals. The front has screw terminals and

Table 32 — Field Connection Terminal Board (TB) Connections (04-14 Size Units)

the back has spade connectors. This board provides connection for the thermostat, space sensor, and most field installed accessories. See Table 32.

TERMINAL

LABEL

C- 2 Transformer 2 Common 24 VAC common 1,2 R- 2 24 VAC power Transformer 2 24 VAC 9,10 SPT+ SPT Space temperature (T55/56) space 10k thermistor 14 SPT- SPT Space temperature (T55/56) space 10k thermistor 13 SPTO SPTO Space temperature offset (T56) space 10k thermistor 12 FDWN FDWN Fire shutdown switch input supply/return/space 24 VAC input 30 X ALRM Alarm output (normally open) space 24 VAC output 3 G G Thermostat G (Fan) space 24 VAC input 4 W1 W1 Thermostat W1 (1st stage heat) space 24 VAC input 5 W2 W2 Thermostat W2 (2nd stage heat) space 24 VAC input 6 Y1 Y1 Thermostat Y1 (1st stage cool) space 24 VAC input 7 Y2 Y2 Thermostat Y2 (2nd stage cool) space 24 VAC input 8 RAT RAT Return Air Temperature Sensor return duct 10k thermistor 15,16 SAT SAT Supply Air Temperature Sensor Blower or duct 10k thermistor 17,18 HUM HUM Humidistat switch input supply/return/space switch input 27 LPWR Analog Sensor Loop power (24vdc) 24 VDC 24 COM Analog sensor common Ground 22 IAQ IAQ Indoor air quality sensor return/space 4- 20 mA input 23

SPRH SP.RH or OAQ

RMOC RM.OC Remote occupancy switch field installed 24 VAC input 25

ENTH ENTH or IAQ.S

*Point name displayed on the scrolling marquee or Navigator display.

DISPLAY NAME* DESCRIPTION SENSOR LOCATION TYPE OF I/O TERMINAL NUMBER

Relative humidity sensor or Outdoor air quality sensor

Outdoor enthalpy switch, or Indoor air quality switch

Not Used 11,19,20,28,29

field installed 4-20 mA input 21

economizer, or return/

space

24 VAC input 26

48/50HC 17-28 Units — Low Voltage Terminal

LEN CCN

CCN

(+) (-)(com) shield

Boards (TB A and TB B)

There are two terminal boards with 16 terminals each, and oriented one mounted above the other. The front have screw terminals and the back have spade connectors. These terminal boards provide a connection point for the thermostat or space sensor and for most field-installed accessories. See Table 33.

Communication Interface Board (CIB)

This circuit board provides a field connection point for unit communications. The Local Equipment Network (LEN) RJ-11 connector allows a hand-held Navigator to be plugged in to access the unit’s menus. The Carrier Comfort Network

(CCN) RJ-11 connector or the CCN screw terminals allow building communication connections. See Fig. 35.

Fig. 35 — Communications Interface Board (CIB)

Central Terminal Board (CTB)

This circuit board is a simple trace board that serves as a junction point between components and the ComfortLink system. It is the distribution center for transformer 1’s power. The integrated gas controller (IGC), electric heater control, compressor control, and unit shutdown all feed through this trace board. See Fig. 36 and Table 34 for the connections through this board.

Fig. 36 — Central Terminal Board (CTB)

Table 33 — Upper and Lower Field Connection Terminal (TB A and TB B) Board Connections (17-28 Size Units)

TERMINAL

BLOCK

Upper (TB A)

Lower (TB B)

*Point name displayed on the scrolling marquee or Navigator™ display.

TERMINAL

LABEL

C- 2 Transformer 2 Common 24 VAC common 1,3,4 R- 2 24 VAC power Transformer 2 24 VAC 13,15,16 SPT+ SPT Space temperature (T55/56) space 10k thermistor 8 SPT- SPT Space temperature (T55/56) space 10k thermistor 7 SPTO SPTO Space temperature offset (T56) space 10k thermistor 5

FDWN FDWN Fire shutdown switch input

X ALRM Alarm output (normally open) space 24 VAC output 2 G G Thermostat G (Fan) space 24 VAC input 6 W1 W1 Thermostat W1 (1st stage heat) space 24 VAC input 8 W2 W2 Thermostat W2 (2nd stage heat) space 24 VAC input 10 Y1 Y1 Thermostat Y1 (1st stage cool) space 24 VAC input 12 Y2 Y2 Thermostat Y2 (2nd stage cool) space 24 VAC input 14 RAT RAT Return Air Temperature Sensor return duct 10k thermistor 1,3 SAT SAT Supply Air Temperature Sensor Blower or duct 10k thermistor 5,7

HUM HUM Humidistat switch input

LPWR

COM Analog sensor common Ground 4 IAQ IAQ Indoor air quality sensor return/space 4- 20 mA input 6

SPRH SP.RH or OAQ

RMOC RM.OC Remote occupancy switch field installed 24 VAC input 10

ENTH ENTH or IAQ.S

R- 2 24 VAC power Transformer 2 24 VAC 15 C- 2 Transformer 2 Common 24 VAC common 16

DISPLAY

NAME*

DESCRIPTION

Analog Sensor Loop power (24vdc)

Relative humidity sensor or Outdoor air quality sensor

Outdoor enthalpy switch, or Indoor air quality switch

SENSOR

LOCATION

supply/return/

space

supply/return/

space

field installed 4-20 mA input 2

economizer, or

return/space

TYPE OF I/O

24 VAC input 11

switch input 9

24 VDC 8

24 VAC input 12

TERMINAL

NUMBER

Table 34 — Central Terminal Board (CTB) Connections

CONNECTION LABEL PIN NUMBER POINT DESCRIPTION 24Vac FROM 24Vac TO

7 Compressor 1 Call MBB ECON

DDC T-STAT

ECON

CLO1/COMP1

CLO2/COMP2

CIRCUIT 1

CIRCUIT 2

CONTRL BOARD

PMR

REMOTE SHUTDOWN

UNIT SHUTDOWN

R Spades

C Spades Ground CONTL BOARD

NOTE: The References above for T1J1 through T1J9 are to show the path of transformer 1 as is goes through the board and safety devices.

SMOKE SHUTDOWN

Scrolling Marquee Display

This device is the keypad interface used to access rooftop information, read sensor values, and test the unit. (See Fig. 37.) The scrolling marquee display is a 4-key, 4-character, 16-segment LED (light-emitting diode) display. Eleven mode LEDs are located on the display as well as an Alarm Status LED. See Basic Control Usage section for further details.

Accessory Navigator™ Display

The accessory hand-held Navigator display can be used with

6 Compressor 2 Call MBB ECON 5 Heat Stage 1 Call MBB CONTL BOARD

4 Heat Stage 2 Call MBB CONTL BOARD 1,2 Comp 1 Call jumper DDC T’STAT CLO1/COMP1 3,4 Comp 2 Call jumper DDC T’STAT CLO2/COMP2

3 Comp 1 Contactor Common CTB C C1 - Coil 4,5 Comp 1 Jumper ECON CIRCUIT 1 LPS

6 Comp 1 Contactor Signal CIRCUIT 1 HPS C1 - Coil

3 Comp 2 Contactor Common CTB C C1 - Coil 4,5 Comp 2 Jumper ECON CIRCUIT 2 LPS

6 Comp 2 Contactor Signal CIRCUIT 2 HPS C1 - Coil

7 ODF Contactor Signal ECON OFC1 - Coil

HPS

LPS Comp 1 jumper CLO1/COMP1 CIRCUIT 1 HPS

HPS

LPS Comp 2 jumper CLO2/COMP2 CIRCUIT 2 HPS

2 Heat Stage 2 Call DDC T’STAT Gas Valve or PL3

3 Heat Stage 1 Call DDC T’STAT IGC-W or PL3

4 IGC Common/Ground CTB C IGC C

6 IGC Call for Indoor fan IGC IFO CONTL BOARD

7 IGC Call for Indoor fan CONTL BOARD MBB

8 IGC power (T1J9) CTB R IGC R

9 Transformer 1 Power (T1J1) TRAN1 24Vac UNIT SHUTDOWN

1 Ground CTB C PMR Device

24V OUT

Comp 1 High Pressure

Switch

Comp 2 High Pressure

Switch

Transformer 1 Common/

Ground

Indoor Fan overload signal

Indoor Fan overload source

Phase Monitor Normally

Remote Disable Switch if installed (T1J4 and T1J5)

Normally Closed Smoke Detector Contact (T1J3)

Smoke Detector Controller

Transformer 1 Power after

(T1J9)

(T1J8)

Phase Monitor Source

(T1J6)

Closed Signal (T1J7)

Power (T1J2)

Common

Safety Chain (T1J9)

CIRCUIT 1 LPS CLO1/COMP1

CIRCUIT 2 LPS CLO2/COMP2

TRAN1 Common CTB C

Fan overload CTB R

PMR Fan overload

UNIT SHUTDOWN PMR Device

PMR Device CONTL BOARD

SMOKE SHUTDOWN PMR

Smoke Detector REMOTE SHUTDOWN

CONTL BOARD Smoke Detector

CTB C Smoke Detector

CONTL BOARD

MODE

Run Status

Service Test

Temperature

Pressures

Setpoints

Inputs

Outputs

Configuration

Time Clock

Operating Modes

Alarms

Alarm Status

ESCAPE

ENTER

48/50HC units. (See Fig. 38.) The Navigator display operates the same way as the scrolling marquee device. The Navigator display plugs into the LEN port on either TB or the ECB board.

Fig. 37 — Scrolling Marquee

2. Cut the CCN wire and strip the ends of the red (+), white

n Sta

tus

Service Te

emp

erature

ressures

Setpoints

Inpu

Outp

uts

Con

fig

tion

Time Clo

Oper

ating

Mod

Alarms

ENTER

E S C

M O

Ala

Sta

tus

TIME

LWT

SETP

12 . 58

54.6° F

44 .1

°F

44.0°F

N A

VIGATOR

Com for t Li nk

(ground), and black (–) conductors. (Substitute appropriate colors for different colored cables.)

3. Connect the red wire to (+) terminal on CIB, the white wire to COM terminal, and the black wire to the (–) terminal.

4. The RJ14 CCN connector on CIB can also be used, but is only intended for temporary connection (for example, a laptop computer running Carrier network software).

5. Restore power to unit.

IMPORTANT: A shorted CCN bus cable will prevent some routines from running and may prevent the unit from starting. If abnormal conditions occur, unplug the connector. If conditions return to normal, check the CCN connector and cable. Run new cable if necessary. A short in one section of the bus can cause problems with all system elements on the bus.

Fig. 38 — Accessory Navigator™ Display

Carrier Comfort Network® (CCN) Interface

The units can be connected to the CCN if desired. The communication bus wiring is a shielded, 3-conductor cable with drain wire and is field supplied and installed. The system elements are connected to the communication bus in a daisy chain arrangement. (See Fig. 39.) The positive pin of each system element communication connector must be wired to the positive pins of the system elements on either side of it. This is also required for the negative and signal ground pins of each system element. Wiring connections for CCN should be made at the CIB. (See Fig. 24, 26, 28 or 29, depending on unit configuration.) Consult the CCN Contractor’s Manual for further information.

NOTE: Conductors and drain wire must be 20 AWG (American Wire Gauge) minimum stranded, tinned copper. Individual conductors must be insulated with PVC, PVC/nylon, vinyl,

Tefl on

, or polyethylene. An aluminum/polyester 100% foil shield and an outer jacket of PVC, PVC/nylon, chrome vinyl, or Teflon with a minimum operating temperature range of – 20°C to 60°C is required. See the following table for acceptable wiring.

MANUFACTURER PART NO.

Alpha 2413 or 5463

Belden 8772

Carol C2528

West Penn 302

It is important when connecting to a CCN communication bus that a color-coding scheme be used for the entire network to simplify the installation. It is recommended that red be used for the signal positive, black for the signal negative and white for the signal ground. Use a similar scheme for cables containing different colored wires.

At each system element, the shields of its communication bus cables must be tied together. The shield screw on CIB can be used to tie the cables together. If the communication bus is entirely within one building, the resulting continuous shield must be connected to a ground at one point only. The shield screw on CIB is not acceptable for grounding. If the communication bus cable exits from one building and enters another, the shields must be connected to grounds at the lightning suppressor in each building where the cable enters or exits the building (one point per building only). To connect the unit to the network:

1. Turn off power to the control box.

1. Teflon is a registered trademark of DuPont.

Protective Devices

COMPRESSOR PROTECTION

Overcurrent

Each compressor has internal line break motor protection.

Overtemperature

Each compressor has an internal protector to protect it against excessively high discharge gas temperatures.

High-Pressure Switch

If the high-pressure switch trips, the compressor will shut down and the compressor safety alarm should trip. Refer to the Alarm section for compressor safety alarms.

EVAPORATOR FAN MOTOR PROTECTION Indoor-fan motors less than 5 hp are equipped with internal

overcurrent and overtemperature protection. Protection devices reset automatically. Disconnect and lock out power when servicing motor. Indoor-fan motors 5 hp and larger are equipped with a manual reset, calibrated trip, magnetic circuit breaker and overcurrent protection. Do not bypass connections or increase the size of the breaker to correct trouble. Determine the cause and correct it before resetting the breaker. On units with VFD, it serves as the motor thermal and over-current protection. Refer to Appendix C for more details on VFD.

CAUTION

EQUIPMENT DAMAGE HAZARD Failure to follow this caution may result in damage to the

unit. DO not bypass the VFD while running the motor. Do not

change VFD parameter associated with motor characteristics, these are factory programmed for motor protection. Damage to the motor or the VFD can occur.

CONDENSER-FAN MOTOR PROTECTION Each condenser-fan motor is internally protected against over-

temperature. Fuses are located in the control box and feed power to the con-

denser fan motors. Always replace blown fuses with the correct size fuse as indicated on the unit fuse label.

SATURATED SUCTION PRESSURE (SSP) If the SSP for a particular circuit is reading below the alarm set

point for an extended period of time, that circuit will be shut down. After 15 minutes, the alarm will automatically reset. If this alarm occurs 3 times consecutively, the circuit will remain locked out until an alarm reset is initiated via CCN or manually via the scrolling marquee display (see Alarms and Alerts section for more details).

CCN BUS

BUILDING SUPERVISOR

ROOFTOP

UNIT

ROOFTOP

UNIT

ROOFTOP

UNIT

ROOFTOP

UNIT

NETWORK

OPTIONS

REMOTE CCN SITE

NON CARRIER

HVAC

EQUIPMENT

AUTODIAL GATEWAY

COMFORT

CONTROLLER

HEATING/COOLING UNITS

LEGEND

TO ADDITIONAL TERMINALS

TERMINAL

SYSTEM

MANAGER

TCU

DAV FAN POWERED MIXING BOX

DAV AIR

TERMINAL

DAV AIR

TERMINAL

ROOFTOP

UNIT

AIR DISTRIBUTION-DIGITAL AIR VOLUME CONTROL (DAV)

CCN CL DAV HVAC TCU

— Carrier Comfort Network

— ComfortLink Controls — Digital Air Volume — Heating, Ventilation, and Air Conditioning — Terminal Control Unit

Fig. 39 — CCN System Architecture

CONDENSATE OVERFLOW SWITCH (COFS) A separate factory installed device can detect a full drain pan.

This device consists of a pan sensor to detect the water level and a relay control switch to read the sensor. The control switch is located in the unit control box and will trip out the compressors on overflow detection. Since this device is in series with the compressor contactor and high pressure switch on any given circuit, ComfortLink does not directly read this. The relay switch is a normally open device that closes when power is applied; this allows the compressor to be energized without problem. If the sensor detects high water levels for 10 seconds straight, it will open the contact breaking the compressor call. The switch will also turn its red LED on. If the water level is low enough for 5 minutes the relay will close again allowing the compressor call. A blinking red LED on the switch indicates that the sensor has been disconnected.

Field-Installed Accessories

SPACE TEMPERATURE SENSOR (T-55) The T-55 space temperature sensor (part no. 33ZCT55SPT) is a

field-installed accessory. The sensor is installed on a building interior wall to measure room air temperature. The T-55 sensor also includes an override button on the front cover to permit occupants to override the Unoccupied Schedule (if programmed). The jumper wire in the installer’s packet must be connected between R and W1 when using a T-55 device.

TB or TB A-SPT+ . . . Sensor Input TB or TB A-SPT– . . . Sensor Common

SPACE TEMPERATURE SENSOR (T-56) The T-56 space temperature sensor (part no. 33ZCT56SPT) is a

field-installed accessory. This sensor includes a sliding scale on the front cover that permits an occupant to adjust the space temperature set point remotely. The T-56 sensor also includes an override button on the front cover to allow occupants to override the unoccupied schedule (if programmed). The jumper wire in the installer’s packet must be connected between R and W1 when using a T-56 device.

TB or TB A-SPT+ ... Sensor Input TB or TB A-SPT– ... Sensor Common TB or TB A-SPTO ... Setpoint Offset Input

SPACE TEMPERATURE SENSOR (T-58) The T-58 space temperature sensor (part no. 33ZCT58SPT) is a

field-installed accessory. The T-58 sensor communicates with the ComfortLink controller, providing space temperature, heating and cooling set points, and mode operation information. The jumper wire in the installer’s packet must be connected between R and W1 when using a T-58 device.

Refer to the T-58 installation instructions for information on installing and configuring the T-58 sensor.

Each T-58 sensor must have a unique address on the CCN. Each T-58 sensor must also be configured with the address of the unit control it is communicating to.

SPACE TEMPERATURE SENSOR AVERAGING See Fig. 40 for space temperature averaging with T-55 sensors

only. If the use of one T-56 sensor is required, refer to Fig. 41. CARRIER ACCESSORY KITS

There are specific accessory kits sold for various field installed accessories. These kits vary based on model, size, voltage, manufacture date, and duct orientation. Some of these kits include Economizer, Power Exhaust, and Electric Heat. Refer to

the Controls Quick Set-Up section for configuration and more information on these accessories.

TWO-POSITION DAMPER The two-position outdoor air damper accessory usage depends

on model size and return duct orientation. This accessory wires directly into the low voltage circuit for the indoor fan control. No other control configuration is needed. On 04-14 size units a 9 pin to 12 pin converter harness is required and is included in the kit or factory installed.

INDOOR AIR QUALITY The indoor air quality (IAQ) sensor (part no. 33ZCSENCO2)

is a field-installed accessory which measures CO

levels in the

air. When installing this sensor, an ECB board must be installed and the unit must be configured for IAQ use by setting

Configuration



AIR.QIA.CF to a value of 1, 2, or 3. See

the Indoor Air Quality section for more information.

TB or TB B-IAQ . . . . . . . . 4-20mA Input

TB or TB B-COM . . . . . . . Sensor Common

TB or TB B-R-2 . . . . . . . . 24vac Output

TB or TB B-C-2 . . . . . . . . common (GND)

OUTDOOR AIR QUALITY The outdoor air quality (OAQ) sensor is a field-installed acces-

sory that measures CO

levels in the air. When installing this

sensor, an ECB board must be installed and the unit must be configured for OAQ use by setting Configura-

tion



AIR.QOA.CF to a value of 1 or 2. See the Indoor Air

Quality section for more information.

TB or TB B-SARH . . . . . . 4-20mA Input

TB or TB B-COM . . . . . . Sensor Common

TB or TB B-R-2 . . . . . . 24vac Output

TB or TB B-C-2 . . . . . . Common (GND)

SMOKE DETECTORS The smoke detectors are field-installed accessories. These detec-

tors can detect smoke in either the return air or supply and return air. When installing either detector, the unit must be configured for fire shutdown by setting Configuration



UNITFS.SW to

normally open (1) or normally closed (2).

TB or TB A-FDWM . . . . . Discrete Input to Board

FILTER STATUS The filter status accessory is a field-installed accessory. This

accessory detects plugged filters. When installing this accessory, the unit must be configured for filter status by setting Con-

figuration



UNITFL.SW to normally open (1) or normally

closed (2). Normally open (1) is the preferred configuration. Filter status wires are pre-run in the unit harness and located near the switch installation location. Refer to the Filter Accessory installation instructions for more information.

FAN STATUS The fan status accessory is a field-installed accessory. This ac-

cessory detects when the indoor fan is blowing air. When installing this accessory, the unit must be configured for fan status by setting Configuration



UNITFN.SW to normally

open (1) or normally closed (2). Normally open (1) is the preferred configuration.

Fan status wires are pre-run in the unit harness and located near the switch installation location. Refer to the Fan Accessory installation instructions for more information.

TO MAIN BASE BOARD

RED

BLK

RED

BLK

RED

BLK

SENSOR 1

SENSOR 2

SENSOR 3

RED

BLK

SENSOR 6SENSOR 5

RED

BLK

SENSOR 4

RED

BLK

RED

BLK

RED

BLK

SENSOR 8SENSOR 7 SENSOR 9

RED

BLK

TB1-T55

SENSOR 1 SENSOR 2 SENSOR 3SENSOR 4

RED

BLK

RED

BLK

RED

BLK

RED

BLK

TO MAIN BASE BOARD

RED

BLK

TB1-T55

SPACE TEMPERATURE AVERAGING — 4 T-55 SENSOR APPLICATION

SPACE TEMPERATURE AVERAGING — 9 T-55 SENSOR APPLICATION

LEGEND

TB — Terminal Block ______ Factory Wiring _ _ _ _ Field Wiring

T-55 SENSOR 1 T-55 SENSOR 2 T-55 SENSOR 3 T-56 SENSOR 4

RED

BLK

RED

BLK

RED

BLK

RED

BLK

TO MAIN

BASE

BOARD

RED

BLK

TB1-T55

TO MAIN

BASE

BOARD

TB1-T55

WHT

Fig. 40 — Space Temperature Sensor Averaging

Fig. 41 — Space Temperature Sensor Averaging with 3 T-55 Sensors and One T-56 Sensor

ENTHALPY SENSORS The enthalpy accessories (part no. CRENTSNG002A00 and

CRENTDIF002A00) are field-installed accessories. The first accessory (outdoor air only) determines when the enthalpy is low relative to a fixed reference. Adding the second accessory (return air) compares the enthalpy between the outdoor and return airstreams. In each case, the enthalpy 4 to 20 mA signals are converted to a switch output which is read by the ECB. When installing this accessory, the unit must be configured for enthalpy-based control by setting Configuration ECONEN.SW to normally open (1). See Fig. 28 and Fig. 29 for wiring details. Normal status is an active switch which tells the control that enthalpy is LOW. The actual switch terminal LOW is normally closed. Refer to the Enthalpy Kit installation instructions for more information on the installation.

RETURN/SUPPLY AIR TEMPERATURE SENSOR The temperature sensor (part no. 33ZCSENSAT) is a field-in-

stalled accessory which may be installed on the common return air duct and/or the common supply air duct near the unit. The duct return air temperature (RAT) may be selected for display. When installing the sensor, the unit must be configured by setting Configuration will allow differential dry bulb control of the economizer. The duct supply air temperature (SAT) may be used to replace the SAT sensor that is internal to the unit. A supply duct SAT measurement is valid for heating mode display while the factorystandard internal SAT is not valid for heating due to its location upstream of the heating section. When installing the supply duct SAT, the unit must be configured by setting Configura-

tion



UNITSAT.H to ENBL. A SAT sensor in the supply

duct is the preferred configuration for systems with Carrier variable volume and temperature (VVT) accessory controls.

The field connection terminal board has SAT and RAT terminals. When installing field sensors, use these terminals accordingly to connect into the MBB.



UNITRAT.S to YES. Using a RAT



IMPORTANT: When wiring a field SAT sensor, the factory installed on must be disconnected from the back of the terminal board.

SPACE HUMIDISTAT The Space Humidistat (part no. -HL-38MG-029) is a wall

mounted device with an adjustable setpoint to control humidity levels. The humidistat input is provided on the field connection terminal board. The Space Humidity Switch configuration,

Configuration

or normally closed status of this input at HIGH humidity.

TB or TB B-HUM . . . . . . . Discrete Input to Board

TB or TB B-R-2 . . . . . . . . 24 VAC Dry Contact Source

NOTE: The humidistat terminals are only in use when the unit is equipped with the Humidi-MiZer factory option.

SPACE HUMIDITY SENSOR The space relative humidity sensor (part no. 33ZCSENDRH-

01 duct mount or 33ZCSENSRH-01 wall mount) is a field-installed accessory. The space relative humidity (RHS) may be selected for use if the outdoor air quality sensor (OAQ) is not used and an economizer board is installed. When installing the relative humidity sensor, the unit must be configured by setting

Configuration

TB or TB B-LPWR . . . . . . . . . . . . . 24 VDC Loop Power

TB or TB B-SPRH . . . . . . . 4-20mA Input Signal



UNITRH.SW, identifies the normally open



UNITRH.S to YES.

Units with EnergyX® System

EnergyX units consist of a factory-installed energy recovery ventilator (ERV) device on a 48/50HC rooftop unit. The EnergyX ERV unit is integrated into the base rooftop unit construction and is factory-wired. The ERV unit contains a control box, supply fan(s), exhaust fan(s), and an enthalpy wheel assembly. All control operations of the ERV are based on the rooftop unit’s operation through communication with the ComfortLink controller. See Fig. 42 and 43 for ERV wiring schematic and component arrangement.

Fig. 42 — Modulating ERV Wiring Schematic

Fig. 43 — EnergyX

ERV Control Box Component Layouts

ENERGYX CONTROL BOARD (EXCB)

See Fig. 44 and Table 35. The EXCB continuously monitors input/output channel informa-

tion received from its inputs and from the Universal Protocol Converter (UPC). The EXCB receives inputs from transducers and discrete inputs. See Options and Accessories section. The

EXCB has relay analog outputs, and is equipped with a LCD screen. The EXCB communicates with a Modbus protocol and is not a CCN device. The EXCB has a reset button that is used to force all the outputs and reset communication.

NOTE: There are hardware jumpers set throughout the board. Do not change these jumpers.

Fig. 44 — EnergyX Control Board (EXCB)

Table 35 — EXCB Input/Output Connections

POINT DESCRIPTION SENSOR LOCATION Input/Output TYPE OF Input/Output CONNECTION PIN NUMBER Download N/A Both Communication J1 LCD Low voltage control box Both Communication J2 Power from TRANS Control box Input 24VAC J3, 1-2 Power to Relays Low voltage control box Output 24VAC J4, 1 Power to UPC Low voltage control box Output 24VDC J4, 3-4 Wheel Rotation Sensor Attached to scoop Input Switch J5, 2-4 Frost Switch Attached to scoop Input Switch J6, 3-4

Filter Status Switch

Motor Status Switches Integrated in motors Input Switch J8, 3-4 Leaving Air Temp Scoop section Input 10K J15, 1-2 Exhaust Air Temp Exhaust air section Input 10K J16, 1-2 Wheel Relay High voltage control box Output Relay J17, 4 2-position Exhaust damper

relay OA fan speed signal N/A Output 2-10vdc J21, 1-3 OA Modulating Damper Intake damper assembly Output 2-10vdc J21, 1-4 EX fan speed signal N/A Output 2-10dvc J22, 1-3 Modbus to UPC Control box Both Communication J23, 1-3 Outside Air pressure

Transducer Exhaust Air pressure

Transducer Building Pressure Sensor Low voltage control box Input 4-20mA J10, 1-6

Attached to scoop and in Exhaust air section

Exhaust damper assembly Output Relay J19, 4

Low voltage control box Input Digital 0-5vdc J24

Low voltage control box Input Digital 0-5vdc J25

Input Switch J7, 3-4

Universal Protocol Converter (UPC)

See Fig. 45 and Table 36. The UPC board is required to convert CCN into Modbus proto-

col. It contains the operating software that runs the ERV logically. The UPC is connected to the ComfortLink controller LEN bus on the rooftop unit.

The DIP switches should be set as follows: 1=off, 2=off, 3=on, 4=on, 5=off, 6=off, 7=on, and 8=off. The address rotary switches should be set to 01 (10’s=0 and 1’s=1). Do not

change these settings.

USER INTERFACE All ERV set point adjustment, service tests, and monitoring are

accomplished through the ComfortLink controller scrolling marquee interface. See the ComfortLink Controls, Start-Up, Operation and Troubleshooting Instructions for further details on ComfortLink controller operation. The ERV EXCB board has a LCD screen that can be used to help troubleshoot communication problems. The following are examples of the text that can be seen on the EXCB’s LCD screen.

LCD Texts

Initialize_LEN Communication This will occur when the ERV is turned on from a power reset. Communication Connected This will be displayed when correct communication is estab-

lished between the RTU and ERV and within the ERV. Comm Failure1 UPC_to_LEN_Fail This occurs if there is a communication problem between the

UPC and ComfortLink MBB. Comm Failure2 UPC_to_EXCB_Fail This will occur if there is a communication problem between

the UPC and the EXCB. Warning UPC TestMODE_Enabled This will occur if the UPC was left in a factory Test mode a

BACview1 Handheld is needed to pull the ERV out of this mode back to normal running mode.

1. BACView is a registered trademark of Automated Logic Corporation.

Fig. 45 — Universal Protocol Converter (UPC)

Table 36 — UPC Input/Output Connections

TERMINAL NAME DESCRIPTION Input/Output TYPE OF Input/Output

24VAC Supply power to UPC Input 24VAC 1 - 2 Port 2 UPC Modbus both Communication 1 - 2 Port 1a UPC LEN both Communication 1 - 3 Port 1b Not used N/A N/A N/A Rnet Local Access both Communication 1 - 5

BACview User Interface or Download Connection

both Communication 1 - 4

CONNECTION PIN

NUMBER

ENTHALPY WHEEL The enthalpy wheel is the “heat exchangers” of the ERV. It

consists of several wheel segments aligned in a cassette assembly. These are not “filters” but made of a desiccant material. The wheel is rotated by a motor and belt, no adjustments required. When the wheel rotates it uses the building exhaust air to pre-conditions the outside air as it passes through the wheel.

MODULATING FAN The modulating ERV is equipped with direct drive variable

speed plenum fans for outside air intake and exhaust air. The motors have built in VFDs that accept a 2 to 10vdc signal from the EXCB. This 2 to 10vdc signal is used by the VFD to determine the speed to run the motor at (0 to 100%). Some ERV models are equipped with multiple outside air and/or exhaust air fans. The additional motor’s signal is parallel off the first motor through the coupling signal plug. Motor status switches are also paralleled for additional motors.

Each motor is capable of diagnosing problems within the motor to provide fan status. The fan status switches are built into each motor and provide a feedback to the EXCB if a problem is detected. The feedback signal is a discrete input that is normally open, when closed the EXCB will initiate the motor status alarm.

MODULATING OUTSIDE AIR DAMPER ERV units include a factory-installed modulating outside air

damper. This damper is controlled in parallel with the modulating intake fan(s). This damper adds static to the outside air and will be open to the same percentage as the outside air fan(s) is running. The modulating outside air damper will also close in the unoccupied mode to prevent unwanted air from being introduced to the rooftop unit.

EnergyX Options and Accessories

The modulating ERV has several optional factory-installed options and field-installed accessories: Frost Protection, Economizer, Wheel Motor Status, Filter Maintenance, horizontal adaptor curb, building pressure sensor, and Outside Air Tempering Kit. Refer to Table 35 for where these options wire into the EXCB.

ECONOMIZER DAMPER (FACTORY-INSTALLED ONLY) The economizer damper is a factory-installed option that pro-

vides a wheel bypass damper. This damper is controlled by the base unit rooftop as an economizer for the purpose of free cooling. The damper is installed adjacent to the ERV wheel to allow outside air to flow through it when opened instead of the wheel. The ERV’s outside air fan(s) will run as this damper is opened to allow proper airflow.

FROST PROTECTION (FACTORY-INSTALLED ONLY) Frost protection is a factory-installed pressure sensor device

which senses a differential pressure across the wheel. This occurs if frost builds up on the wheel. The sensor closes its contact when the pressure differential is greater than the setpoint. When the EXCB reads the contact closer it will activate defrost mode. The setpoint is a dial on the sensor, is adjustable from

0.2 to 2.0 in.wg, and is factory preset to 2.0 in.wg. Changing this setting may cause false signal causing defrost mode when not needed.

WHEEL MOTOR STATUS (FIELD-INSTALLED ONLY) The wheel motor status accessory can be installed in the field

and consists of a wheel motion proxy sensor and a relay. The wheel motion sensor is aimed at the wheel to detect rotation. If the wheel does not rotate at the appropriate speed the sensor will open causing the rotation monitor relay to close a contact to initiate the wheel status alarm. The motion sensor is factory set at the highest speed (clockwise until stop) and should not be

changed. Refer to the troubleshooting section for details on the alarms.

FILTER MAINTENANCE (FIELD-INSTALLED ONLY) Filter maintenance consists of two field-installed pressure sen-

sor devices which sense differential pressure across the ERV filters. This occurs if dirt builds up on the filters. There is a separate pressure sensor for each filter (outside air and exhaust air). The sensor closes its contact when the pressure differential is greater than the setpoint. The sensors are wired in parallel, so when the EXCB reads a contact closer from either sensor it will activate the filter alarm. The setpoint is a dial on the sensor, is adjustable from 0.2 to 2.0 in.wg, and is factory preset to

2.0 in.wg. Changing this setting may cause false signal causing false dirty filter alarms.

HORIZONTAL TRANSITION CURB (FIELD-INSTALLED ONLY)

EnergyX requires horizontal return then a horizontal transition curb must be used. Units cannot be field converted to horizontal supply. To accomplish horizontal supply a horizontal transition curb must be used.

units must receive vertical return. If the application

SERVICE AND MAINTENANCE

EnergyX System Cleaning

WHEEL AND SEGMENT CLEANING Wheel cleaning periodicity is application dependent. Field ex-

perience shows that offices, schools and other “clean” environments will often go 10 years before any build up of dust and dirt is noticed. Other applications such as restaurants, casinos and factory environments may experience fairly rapid build-up of contaminants and may require multiple cleanings per year to maintain airflow and recovery efficiencies.

All air-to-air energy recovery devices will become dirty over time, even with well-maintained filtration. Proper filtration usage and changes will improve the life of the wheel transfer segments. Once the wheel is exposed to oils, tars or greases in either the supply or exhaust air streams, these pollutants deposit on the rotary surface which then become “sticky” and begin to attract and hold the dust particles that previously passed thru the wheel. Over time this particle build up can lead to blocked airflow passages, loss of recovery, excessive pressure drop through the wheel and loss of energy savings.

1. Follow steps for wheel and segment removal to remove the affected energy transfer matrix segments. (For onepiece wheels 25 inches in diameter and smaller, remove the entire wheel from the cassette.)

2. Gently brush the wheel face to remove loose accumulated dirt.

3. Wash the segments with a non-acid based (evaporator) coil cleaner or alkaline detergent solution. Non-acid based coil cleaner such as KMP Acti-Clean AK-1 concentrate in a 5% solution has been demonstrated to provide excellent results. DO NOT use acid based cleaners, aromatic sol- vents, temperatures in excess of 170°F or steam. Damage to the wheel will result.

4. Soak the wheel and/or segments in the cleaning solution until all grease and tar deposits are loosened. An overnight soak may be required to adequately loosen heavy deposits of tar and oil based contaminants.

5. Internal heat exchange surfaces may be examined by separating the polymer strips by hand. (Note: some staining of the desiccant may remain and is not harmful to performance.)

6. After soaking, rinse the dirty solution from the wheel segments until the water runs clear.

7. Allow excess water to drain prior to replacing segments in

Rotation

Adjusting Screws

Feeler Gauge

To Adjust

Hammer used as a “stop”

the wheel. A small amount of water remaining in the wheel will be dried out by the airflow.

FILTERS Clean or replace at start of each heating and cooling seasons, or

more often if operating conditions require (based on filter manufacture recommendation or filter status alarm indication).

OUTDOOR-AIR INLET SCREENS Clean screens with steam or hot water and a mild detergent at

the beginning of each heating and cooling season. Do not use throwaway filters in place of screens.

EnergyX Component Lubrication

All component bearings are sealed and do not require lubrication.

EnergyX Wheel Drive Adjustment

The wheel motor and drives do not require adjustment. The wheel drive pulley is secured to the drive motor shaft by a set screw. The set screw is secured with removable locktite to prevent loosening. Annually confirm set screw is secure. The wheel drive belt is a urethane stretch belt designed to provide constant tension throughout the life of the belt. Inspect the drive belt annually for proper tracking and tension. A properly tensioned belt will turn the wheel immediately after power is applied with no visible slippage during start-up.

EnergyX Wheel Air Seal Adjustment

Diameter seals are provided on each wheel cassette to minimize transfer of air between the counter flowing airstreams. Follow below instructions if adjustment is needed.

1. Loosen diameter seal adjusting screws and back seals away from the wheel surface. See Fig. 46.

2. Rotate the wheel clockwise until two opposing spokes are hidden behind the bearing support beam.

3. Using a folded piece of paper as a feeder gauge, position the paper between the seal and wheel surface.

4. Adjust the seal towards wheel surface until a slight friction on the feeder gauge (paper) is detected while moving the gauge along the length of the spoke.

5. Re-tighten adjustment screws and re-check clearance with the feeder gauge.

Wheel and Segment Removal / Installation

The wheel and segments represent a substantial portion of the value of the cassette therefore must be handled with care and never be dropped. Use a suitable crate or harness to lift wheel and segments to a roof surface, never use the shipping cartons for this purpose. Wheel and segments may require “slight” persuasion during installation and removal but never forced or impacted with a hammer or similar tool. The wheel assembly can be removed and installed or the wheel or segments can be removed from the assembly.

WARNING

UNIT DAMAGE HAZARD Failure to follow this caution may result in equipment dam-

age. The weight of the wheel assembly must be supported when

the assembly is extended from the unit chassis to avoid damage to wheel or unit.

The ERV wheel on 3 ton units is a 19 inch whole wheel assembly. ERV wheels on 4 to 25 ton units are segmented wheel assemblies. Follow the correct section below for removing and installing specific wheels from their assemblies. To remove or install the whole assembly, simply side in or out the assembly noting the motor power plug.

Wheel Segment Removal / Installation

1. Turn off, lockout and tag-out electrical power to unit.

2. Open access door to the EnergyX the unit.

3. Slide the entire wheel assembly out until the necessary segment(s) of the wheel can be accessed. Support the weight of the wheel assembly as necessary to avoid damage to wheel or unit.

module on back side of

WARNING

PERSONAL INJURY HAZARD Failure to follow this caution may result in personal injury. Weight of the installed segment will cause the wheel to ac-

celerate in rotation as segments are removed. Failure to maintain control of the wheel rotation while installing all segments could cause severe injury to fingers or hand caught between revolving spokes and the bearing support beam. The handle of a tool such as a hammer, should be inserted through spokes and above or below bearing support beams to limit rotation of unbalanced wheel. See Fig. 47.

Fig. 46 — Diameter Seal Adjustment

Fig. 47 — Wheel Stop

4. Position one segment opening at the top of the cassette.

Catch Pull Tab

Imbedded Stiffeners

5. Unlock and open the segment retaining brackets on both sides of the selected segment opening. See Fig. 48.

Fig. 48 — Segment Retaining Brackets

6. Gently lift segment outward.

7. Close segment retaining latches and rotate wheel 180° to remove next segment. Follow this pattern to remove all segments and keep wheel balanced.

8. To install the wheel segments, hold the segment as vertically as possible and centered between spokes, insert nose of segment downward between the hub plates. See Fig. 49.

NOTE: The face of the segment, with the imbedded stiffener (vertical support between nose and rim end of segment) must face the motor side of the cassette. See Fig. 50.

9. Ease the segment downward until its outer rim clears the inside of the wheel rim. Press the segment inward against the spoke flanges.

10. Close and latch segment retaining brackets to the position shown in Fig. 48. Make certain the retaining bracket is fully engaged under the catch.

11. Slowly rotate, by hand, the first installed segment to the bottom of the cassette, and then install the second segment opposite the first. Repeat this sequence with the two installed segments rotated to the horizontal position to balance the weight of installed segments.

12. Continue this sequence with the remaining segments as necessary.

13. When complete, close access door and remove lockout and tag-out to apply power to unit.

WHOLE WHEEL REMOVAL / INSTALLATION (19 INCH WHEEL)

These wheels are secured to the shaft and bearing support beam by a Philips head screw and hub cover. Follow the steps below for removal and reverse for installation. See Fig. 51.

1. Turn off, lockout and tag-out electrical power to unit.

2. Open access door to the EnergyX

module on back side of

the unit.

3. Remove front seal assembly (pulley side of the cassette) if present.

4. Remove belt from pulley and position temporarily around wheel rim.

5. Remove the hub cover from the wheel.

NOTE: The wheel to shaft alignment pin under the hub cover. Insure this pin engages the notch at the end of the shaft when reinstalling the wheel.

6. Pull the wheel straight off the shaft. Handle with care.

Fig. 49 — Segment Removal

Fig. 50 — Imbedded Wheel Stiffeners (Shown for

Motor Side of Wheel Assembly)

Alignment

Hub Cover

Wheel and Hub

Cassette Housing/Frame

Shaft

Bearings (2)

Fig. 51 — 19 inch Wheel Mount

WHOLE WHEEL REMOVAL/INSTALLATION (25-46 INCH WHEELS)

These wheels include the shaft and are secured to two wheel support beams by two flange bearings with locking collars.

Follow the steps below for removal and reverse for installation. See Fig. 52.

1. Loosen the two set screws on each to the two wheel bearings.

2. Remove belt from pulley and position temporarily around wheel rim.

3. Remove pulley side wheel support beam with bearing, by removing four support beam screws.

4. Pull the wheel with the shaft straight out of the motor side wheel support beam and bearing. Handle wheel with care.

5. When replacing wheel be certain to tighten four bearing

Wheel, Hub and Shaft

Set Screws (2 each)

Flange Bearings (2)

Wheel Support Beams

set screws. Premature bearing failure can occur if not set tightly.

Fig. 52 — 25-46 Inch Wheel Mount

Outside Air and Exhaust Air Hood Removal

OUTSIDE AIR HOOD REMOVAL

1. Turn off, lockout and tag-out electrical power to unit.

2. Remove the hood by removing the self-sealing screws along the perimeter of the hood. See Fig. 53.

NOTE: Even after all screws have been removed from entire perimeter of hood, it will still be difficult to remove due to the gasket applied from original installation. Take care not to damage the gasket. If damage occurs use equivalent gasket to replace before reattaching the hood.

3. Disconnect the green (HIGH) and yellow (LOW) tubes attached to the quick connects located inside the ERV. Do NOT damage the tubes.

EXHAUST AIR HOOD REMOVAL

1. Turn off, lockout and tag-out electrical power to unit.

2. Remove the hood by removing the self-sealing screws along the perimeter of the hood.

Fig. 53 — Outside Air Hood Removal

Detail “A”

High and Low

Quick Connects

Fig. 54 — Exhaust Air Hood Removal

Outside Air Motorized Damper Removal

1. Turn off, lockout and tag-out electrical power to unit.

2. Remove the outside air motorized damper access panel by removing the self-sealing screws around the perimeter (see Fig. 54).

NOTE: Even after all of the screws have been removed from the panel it still may be difficult to remove due to the gasket applied from the original installation. Take care not to damage the gasket. If damage occurs use 9430-2300 gasket to replace before reattaching the panel.

3. Disconnect the connector labeled PL06 for the damper motor from the wiring harness inside the air chamber of the EnergyX

4. Slide out the outside air motorized damper by pulling it along the track guides. See Fig. 55.

unit.

Outside Air and Exhaust Fan Replacement

OUTSIDE AIR FAN REMOVAL

1. Turn off, lockout and tag-out electrical power to unit.

2. Remove outside air hood (see procedure on page 96).

3. Remove outside air motorized damper (see procedure above).

4. Remove the lower and upper guides for the outside air motorized damper by removing the screws along the

length of the flanges connecting them to the inside of the ERV unit.

5. Disconnect the connector PL121, PL123 and the power wires for the exhaust fan motor from the wiring harness inside the air chamber of the EnergyX unit.

6. Remove the fasteners at each corner of the outside air fan that secure the outside air fan front panel to the dividing wall by access through the hood opening of the ERV. See Fig. 56.

NOTE: See instructions for removing the wheel and supply filters if more room is needed to access the outside air fan through the door for better maneuverability.

7. Remove the four bolts holding the front fan panel onto the rest of the outside air fan assembly. Completely remove this panel from the ERV.

NOTE: Tilt the fan assembly front panel to fit it through the hood opening.

8. Pull the outside air fan out through the hood opening. See Fig. 57.

NOTE: Tilt the fan assembly to fit its back panel through the opening in the dividing wall.

9. Repeat Steps 6, 7, and 8 to remove the second fan.

Fig. 55 — Outside Air Motorized Damper Removal

Outside Air Damper Access Panel

Motorized Outside Air Damper

Detail “A” Outside Air Fan Assembly

Remove Bolts: 4 - Places

Outside Air Fan Assembly, see Detail A (access panel not shown)

Remove Fasteners: 4 - Places

Fig. 56 — Remove Fasteners from Corners of Outside Air Fan Assembly

Fig. 57 — Outside Air Fan Removal

EXHAUST FAN REMOVAL

1. Turn off, lockout and tag-out electrical power to unit.

2. Remove the exhaust fan access panel by removing the self-sealing screws around the perimeter (see Fig. 57).

3. Open the door to the EnergyX unit in order to gain access to the exhaust fan front panel.

NOTE: See instructions for removing the wheel and exhaust filters if more room is needed to access the exhaust fan front panel.

4. If installed, remove the exhaust motorized damper.

5. Remove the fasteners around the perimeter of the exhaust fan that secure the exhaust fan front panel to the dividing wall by access through the door of the unit. See Fig. 58.

6. Disconnect connectors PL120 and PL122 as well as the power wires for the e xhaust fan motor from the wiring harness inside the air chamber of the EnergyX unit.

7. Remove the exhaust fan by moving it back and then out the side of the unit through the exhaust motorized damper access panel. See Fig. 59.

8. Repeat steps 5, 6, and 7 to remove the second exhaust fan on size 20, 24, and 28 models.

Fig. 58 — Exhaust Fan Assembly - Fastener Locations

Detail “A” Exhaust Fan Assembly secured to Dividing Wall

Remove Fasteners: 8 - Places

100

Carrier 48HC 04-28, 50HC 04-28 Controls, Start-up, Operation And Troubleshooting

Specifications and Main Features

Frequently Asked Questions

User Manual

TABLE OF CONTENTS

SAFETY CONSIDERATIONS

GENERAL

BASIC CONTROL USAGE

ComfortLink Control

Scrolling Marquee

Accessory Navigator™ Display

Operation

System Pilot™ and Touch Pilot™ Devices

CCN Tables and Display

Force Hierarchy

Generic Status Display Table

Conventions Used in This Manual

START-UP

Unit Preparation

Compressor Mounting

Refrigerant Service Ports

Crankcase Heater(s)

Compressor Rotation

Power Supply

Internal Wiring

Evaporator Fan

48/50HC 04-06 UNITS WITH DIRECT DRIVE FANS The ECM has 5 speed taps to allow a range of fan perfor-

Condenser Fans and Motors

Return-Air Filters

Outdoor-Air Inlet Screens

Accessory Installation

Orifice Change (48HC)

Gas Heat (48HC)

Units with EnergyX® System

CONTROLS QUICK SET-UP

Control Set Point and Configuration Log

Thermostat Control

Space Temperature Sensor Control - Direct Wired (T-55 or T-56 or T-59)

T-58 Communicating Room Sensor

CCN Linkage Control

System Pilot™ - Communication Space Sensor

Thermidistat Control

Space Humidistat Control

Relative Humidity Sensor Control

CCN Communication

Accessories

Programming Operating Schedules

SERVICE TEST

Independent Outputs

Fan Test

Cooling Test

Humidi-MiZer® Test

Heating Test

THIRD PARTY CONTROL

Cooling/Heating Control

Dehumidification Control

Remote Occupancy

Fire Shutdown

Alarm Output

Economizer Damper Control

CONTROLS OPERATION

Display Configuration

Unit Configuration

Modes

General Operation

Temperature Setpoint Determination

Occupancy Determination

Cooling Operation

Heating Operation

duced by one without honoring H.DEC. HEAT RELAY CONTROL

Economizer

ECONOMIZER FAULT DETECTION AND DIAGNOSTICS (FDD) CONTROL

ECONOMIZER ACTUATOR COMMUNICATION

Indoor Air Quality (IAQ)

Optional Humidi-MiZer® Dehumidification System

Temperature Compensated Start

Carrier Comfort Network® (CCN) Configuration

Demand Limit

Linkage

Alarm Handling