Carrier 48LC 04, 48LC 05, 50LC 05, 50LC 06, 48LC 06 Controls, Start-up, Operation And Troubleshooting

48/50LC 04---06
Single Package Rooftop Units
with ComfortLink Controls Version 1.X
and PURONr (R---410A) Refrigerant

Controls, Start---Up, Operation

and Troubleshooting

IMPORTANT: This literature covers 48/50LC 04--06 models with
ComfortLink Software version 1.x.

TABLE OF CONTENTS

Page

SAFETY CONSIDERATIONS 2.........................

GENERAL 3.........................................

BASIC CONTROL USAGE 3...........................

ComfortLink Control 3................................

Scrolling Marquee 3..................................

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

Operation 4.........................................

System Pilott and Touch Pilot Devices 4.................

CCN Tables and Display 4.............................

Conventions Used in This Manual 6......................

START--UP 6.........................................

Unit Preparation 6....................................

Compressor Mounting 6...............................

Refrigerant Service Ports 6.............................

Crankcase Heater 6...................................

Compressor Rotation 6................................

Power Supply 6.....................................

Internal Wiring 6.....................................

Evaporator Fan 6....................................

Condenser Fans and Motors 7...........................

Return--Air Filters 7..................................

Outdoor--Air Inlet Screens 7............................

Accessory Installation 7...............................

Orifice Change (48LC) 7..............................

Gas Heat (48LC) 8...................................

CONTROLS QUICK SET--UP 8.........................

Control Set Point and Confirmation Log 8.................

Thermostat Control 8.................................

Space Temperature Sensor Control -- Direct Wired

(T--55 or T--56 or T--59) 8.............................

T--58 Communicating Room Sensor 8....................

CCN Linkage Control 8...............................

System Pilott -- Communication Space Sensor 8...........

Thermidistat Control 8................................

Space Humidistat Control 9............................

Relative Humidity Sensor Control 9......................

CCN Communication 9...............................

Accessories 9.......................................

Programming Operating Schedules 9.....................

SERVICE TEST 11....................................

Independent Outputs 11...............................

Fan Test 11.........................................

Cooling Test 11.....................................

Heating Test 11......................................

THIRD PARTY CONTROL 11..........................

Cooling/Heating Control 11............................

Dehumidification Control 11...........................

Remote Occupancy 12................................

Fire Shutdown 12....................................

Alarm Output 12.....................................

Economizer Damper Control 12.........................

CONTROLS OPERATION 12...........................

Display Configuration 12..............................

Unit Configuration 12.................................

Modes 13..........................................

General Operation 13.................................

Temperature Setpoint Determination 14...................

Occupancy Determination 14...........................

Indoor Fan Operation 14...............................

Cooling Operation 15.................................

Heating Operation 18.................................

Economizer 19......................................

Air--Side Economizer High Limit Switches Control 22.......

Indoor Air Quality (IAQ) 23............................

Temperature Compensated Start 25.......................

Carrier Comfort Network (CCN)

Demand Limit 26....................................

Linkage 26.........................................

Alarm Handling 26...................................

TROUBLESHOOTING 27..............................

Complete Unit Stoppage 27............................

Restart Procedure 27..................................

Alarms and Alerts 27.................................

Control Module Communication 32......................

R

Configuration 25.........

Communication Failures 32............................

Cooling Troubleshooting 33............................

Economizer Troubleshooting 34.........................

Title 24 FDD Status Points 34..........................

Heating Troubleshooting 36............................

Phase Loss Protection 39..............................

Thermistor Troubleshooting 39.........................

Transducer Troubleshooting 40.........................

Forcing Inputs and Outputs 40..........................

MAJOR SYSTEM COMPONENTS 43....................

General 43.........................................

Main Base Board (MBB) 49............................

Economizer Control Board (ECB) 51.....................

Integrated Gas Control (IGC) Board 53...................

Low Voltage Terminal Board 54.........................

Communication Interface Board (CIB) 54.................

Central Terminal Board (CTB) 54........................

Variable Frequency Drive (VFD) 56......................

48/50LC

VFD Diagnostics (with Keypad) 58......................

Scrolling Marquee Display 61..........................

Accessory Navigatort Display 61.......................

R

Carrier Comfort Network (CCN)

Protective Devices 63.................................

Field--Installed Accessories 63..........................

APPENDIX -- LOCAL DISPLAY AND

CCN TABLES 66.....................................

CONTROL SET POINT AND CONFIGURATION LOG 80....

UNIT START--UP CHECKLIST 87.......................

Interface 61.............

SAFETY CONSIDERATIONS

Installation and servicing of air-conditioning equipment can be
hazardous due to system pressure and electrical components. Only
trained and qualified service personnel should install, repair, or
service air-conditioning equipment. Untrained personnel can
perform the basic maintenance functions of replacing filters.
Trained service personnel should perform all other operations.

When working on air-conditioning equipment, observe precautions
in the literature, tags and labels attached to the unit, and other
safety precautions that may apply. Follow all safety codes. Wear
safety glasses and work gloves. Use quenching cloth for unbrazing
operations. Have fire extinguishers available for all brazing
operations.

Follow all safety codes. Wear safety glasses and work gloves. Have
fire extinguisher available. Read these instructions thoroughly and
follow all warnings or cautions attached to the unit. Consult local
building codes and National Electrical Code (NEC) for special
requirements.

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, and
CAUTION. These words are used with the safety--alert symbol.
DANGER identifies the most serious hazards which will result in
severe personal injury or death. WARNING signifies a hazard
which could result in personal 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 lockout
tag. Ensure electrical service to rooftop unit agrees with
voltage and amperage listed on the unit rating plate.

.

!

CAUTION

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.

2

!

WARNING

FIRE, EXPLOSION HAZARD

Failure to follow this warning could result in personal
injury, death and/or property damage.

Improper installation, adjustment, alteration, service, or
maintenance can cause property damage, personal injury, or
loss of life. Refer to the User’s Information Manual
provided with this unit for more details.
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:

1. DO NOT try to light any appliance.

2. DO NOT touch any electrical switch, or use any
phone in your building.

3.IMMEDIATELY call your gas supplier from a
neighbor’s phone. Follow the gas supplier’s
instructions.

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

GENERAL

This publication contains Start--Up, Controls, Operation, Service,
and Troubleshooting information for the 48/50LC rooftop units.
(See Table 1.) These units are equipped with ComfortLink controls
version 1.X or higher and use Puronr 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
Staged Air Volume (SAVt) units that provide stand--alone or
network operation.

Table 1 – Rooftop Units

MODEL SIZE NOMINAL TONS

04 3

48/50LC

05 4
06 5

BASIC CONTROL USAGE

ComfortLink Control

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

The ComfortLink control is fully communicating and cable-ready
for connection to the Carrier Comfort Network (CCN) 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 control
equipped units) using a 3-wire communication bus.

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.

MODE

Run Status

Service Test

Temperature

Pressures

Setpoints

Inputs

Outputs

Configuration

Time Clock

Operating Modes

Alarms

Alarm Status

ESCAPE

ENTER

C06320

Fig. 1 -- Scrolling Marquee

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:

S Run Status
S Service Test
S Temperatures
S Pressures
S Set points
S Inputs
S Outputs
S Configuration
S Timeclock
S Operating Modes
S 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.)

48/50LC

3

Accessory Navigator Display

The accessory hand-held Navigator display can be used with the
48/50LC 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).

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48/50LC

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
ComfortLink control system. The displays have up and down
arrow 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.

C06321

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. 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 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 Pilott 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, 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.

4

Table 2 – Scrolling Marquee Mode and Menu Display Structure

/

RUN

STATUS

Auto View

of

Run Status

(VIEW)



Softwa re

Version

Numbers

(VERS)



Control

Modes

(MODE)



Cooling

Status

(COOL)



Heating

Status

(HEAT)



Economizer

Status

(ECON)



Component

Run Hours

(HRS)



Component

Starts

(STRT)

NAVIGATE/
EXIT

SERVICE

TEST

Service Test

Mode

(TEST)



Test Indepen-

dent

Outputs

(INDP)



Te st F an s

(FANS)



Test Cooling

(COOL)



Te st H eat i ng

(HEAT)

SCROLL

TEMPERATURES PRESSURES SETPOINTS INPUTS OUTPUTS CONFIGURATION

Air

Temperatures

(AIR.T)



Refrigerant

Temperatures

(REF.T)

MODIFY
SELECT

+

-

PAGE

C06322

Fig. 3 -- System Pilott 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 Pilots and Touch Pilots write Supervisor Forces at level 4.
Network programs can be set to write different level priority forces.

Thermostat

Inputs

(STAT)



General

Inputs

(GEN.I)



Air Quality

Inputs

(AIR.Q)

Fan

Outputs

(FANS)



Cool
Outputs
(COOL)



Heat
Outputs

(HEAT)



Economiz-

er
Outputs
(ECON)



Alarm
Relay

(ALRM)

Display

Configuration

(DISP)



Unit

Configuration

(UNIT)



Indoor Fan

Configuration

(I.FAN)



Cooling

Configuration

(COOL)



Heating

Configuration

(HEAT)



Economizer

Configuration

(ECON)



Air Quality

Cfg.

(AIR.Q)



Alarm Relay

Config.

(ALM.O)



Sensor

Calibration

(TRIM)



CCN

TIME

CLOCK

Time of

(TIME)

Month,

Day and

(DATE)

Daylight

Savings

(DST)

Local Time

Schedule

(SCH.L)

Local

Holiday

Schedules

(HOL.L)

Day



Date

Yea r



Time





OPERATING

MODES

Control

Modes

(MODE)



Cool Mode

Diagnostic

(COOL)



Heat Mode

Diagnostic

(HEAT)



Economizer

Diagnostic

(ECON)



Demand

Listing

(DMD.L)

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 (ComfortVIEWt,
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.

ALARMS

Reset All

Current

Alarms

(R.CURR)



Reset
Alarm

History

(R.HIST)



Currently

Active

Alarms

(CURR)



Alarm

HIstory

(HIST)

48/50LC

5

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

UNITT.C TL .

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,
ConfigurationUNITT.CT L =1(1 Stage Y1).

Pressing the ESCAPE and ENTER keys simultaneously will scroll
an expanded text description of the point name across the display.

48/50LC

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.

START-UP

IMPORTANT: Do not attempt to start unit, even momentarily,

until all items on the Start--Up Checklist (see page 87) 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 holddown bolts.

Refrigerant Service Ports

The refrigerant system has a total of 3 Schrader-type 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

The compressor is equipped with a crankcase heater. There is a
temperature switch used to turn the crankcase heaters on and off
when the compressor is not running. If the ambient is above 75_F
the switch will prevent the crankcase heater from turning on, and if
the ambient is below 60_F the switch will allow the crankcase
heater on.

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

Compressor Rotation

!

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
L1-L2-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 A Failure to Pressurize,”.

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 (TRAN1, TRAN2 and TRAN3) 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.

Evaporator Fan

The Evaporator fan should be checked and may need to be
adjusted for specific applications. The unit can have a direct drive
Electronic Commutated Motor (ECM) fan system or a belt drive
motor powered by a Variable Frequency Drive (VFD). Refer to the
unit product data for Fan Performance tables and physical data.

On direct drive units, the ECM has 5 speed taps to allow a range of
fan performance. The ComfortlLink control has 3 output wires to
connect to 3 different taps. From the factory the low and high
speed wires are connected to the first and second speed taps,
respectively. The ventilation speed tap is disconnected. 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. If the low and high
speed wires are moved to higher taps, the ventilation speed wire
can be wired into the motor. To activate the use of the ventilation



speed wire, the Number of Speeds (Configurations



NSPD) configuration must be set to 3.

On 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,
first adjust the pulley settings to provide the applications full load
design air flow when running at the Supply Fan Maximum Speed



(Configuration
then be adjusted with Supply Fan Speed 1 (Configuration



I.FANF. S P 1 ), Supply Fan Speed 2 (ConfigurationI.FAN



F. S P 2 ), Supply Fan Speed 3 (ConfigurationI.FANF. S P 3 ),

and Fan Speed – Ventilation (Configuration
Set the indoor fan pulley to the 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 the major components section.

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.

6

UNITFS.MX). The unit operating speeds can



I.FANFS.VN).

I.FAN

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



(Configuration

ECONIDF.C). Default values for Indoor

Fan Max Speed CFM (IDF.C) are at 400 CFM per ton
(1200CFM for the 04 size,1600 CFM for the 05 size, and 2000
CFM for the 06 size). It is preferred to use the supply duct CFM
from an air balance report to configure the Indoor Fan Max
Speed CFM (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



INDPECON) to 0 (Economizer Damper Closed) and

Test



Indoor Fan Speed Test (Service Test

FANSF. S P D ) equal to

Supply Fan Maximum Speed (FS.MX). Measure the supply to
return duct static pressure difference and indoor fan RPM.Make
correction to static pressure 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 pressure and RPM cross.

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 (48LC)

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.

48/50LC

INDOOR
BLOWER

CONTROL BOX
ACCESS PANEL

GAS SECTION
ACCESS PANEL

ACCESS
PAN EL

FILTER
ACCESS PANEL

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

INDOOR COIL
ACCESS PANEL

UNIT BACKUNIT FRONT

C12218

7

Gas Heat (48LC)

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
field-supplied manual shutoff valve. (See Fig. 5.)

MANUAL SHUT OFF

(FIELD SUPPLIED)

PRESSURE TAP

(1/8˝ NPT PLUG)

TO

UNIT

48/50LC

UNION

Fig. 5 -- 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.

SEDIMENT TRAP

CONTROLS QUICK SET--UP

The following information will provide a quick guide to setting up
and configuring the 48/50LC 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 require
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

80. should be filled out and left with the unit at all times, a copy
should also be provided to the equipment owner.

GAS

SUPPLY

C09242

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.CTL,
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 for additional
information.

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.

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’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 for additional information.

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.

CCN Linkage Control

The CCN communication must be properly configured for the
48/50LC 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HEATSAT.H 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.

System Pilott -- 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’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 theinputs are provided on the field connection terminal board. The
unit control type configuration, ConfigurationUNITU.CTL,
default value is for thermostat (2) so there is no need to configure this

8

item. The thermostat control type configuration,
ConfigurationUNITT. CT L, selects the unit response to the
thermostat inputs above. See below for Space Humidity Switch.

Space Humidistat Control

The HUM terminal can be used on the Field Connection board when
the isolation relay is installed between the MBB and TB. The Space
Humidity Switch configuration, ConfigurationUNITRH.SW,
identifies the normally open or normally closed status of this input at
LOW humidity.

Relative Humidity Sensor Control

For units with 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UNITRH.S=YES, identifies
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 Dehumidification Operation sections for
more information.

CCN Communication

Configure ConfigurationCCNCCN.A to desired element
number. (Default is 1.) Configure ConfigurationCCN CCN.B
to desired bus number. (Default is 0.) Configure
ConfigurationCCNBAUD to desired code number for baud
rate (Default is 3 = 9600 baud).

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ECONEC.EN 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 Configuration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 ConfigurationHEATHT.TY to a
value of 2. The number of electric heat stages must be configured
by setting ConfigurationHEATN.HTR per the installed
heater.

Fire Shutdown

If a Fire Shutdown or Smoke Detector accessory was field
installed, the unit must be configured for it by setting
Configuration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 ConfigurationECONEN.SW,
identifies the normally open or normally 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AIR.QII.CF,
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.

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

IAQ Sensor

If a CO2Sensor accessory was field installed, the unit must be
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 ConfigurationAIR.Q
OA.CF selects the unit response to this input. 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UNITFN.SW 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UNITFL.SW to
normally open (1) or normally closed (2). Normally open (1) is the
preferred configuration.

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.

48/50LC

9

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

Table 3 – Setting an Occupied Time Schedule — Weekdays Only for 7:30 to 22:30

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 3 for an example of setting the schedule.

48/50LC

DISPLAY

MENU

TIMECLOCK

SCH.L

SUB-SUB

MODE

PER.1

KEYPAD

ENTRY

ENTER Local Occupancy Schedule

ENTER OCC.1 Period Occupied Time

ENTER 00.00 Scrolling stops

ENTER 00.00 Hours Flash

Y 07.00 Select 7

ENTER 07.00 Change accepted, minutes flash

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 Change accepted, minutes flash

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

10

SERVICE TEST

The Service Test function can be used to verify proper operation of
compressors, heating stages, 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 4 for point details).

Service Test mode has the following changes from normal
operation:

S 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.

S Circuit alerts are limited to 1 strike (versus 3) beforechanging to

alarm shut down state.

S The status of ALM.N is ignored so all alerts and alarms are

broadcast on CCN.

S The words “SERVICE TEST” areinserted 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, and alarm relay. 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 economizeris using the factory default
Digital Control Type (ConfigurationECONE.CTL is 1 or 2)
then the Economizer 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.

Fan Test

The fans (FANS) submenu is used to change output status for the
indoor fan. On Direct Drive ECM fan units the indoor fan relays
can be energized or de--energized using the IDF1, IDF2, and IDF3
test. For units with a VFD the indoor fan speed test (F.SPD) is
available. F.SPD runs the fan at the desired speed entered. IDF Fan
Mode (F.MOD) will run the fan at the programmed speed for each
mode.

Cooling Test

The cooling (COOL) submenu is used to change output status for
the compressor, loader, and the low ambient outdoor fan. The fans
(FANS) 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
Supply Cooling Fan Speed configuration point
(ConfigurationI.FANF. S P 2 ) when one compressor is turned
on. The Reduced Cool Fan Speed (F.SPD) can be used to change
the fan speed during cool test. When the compressor and loader are
turned on the fan will run at Supply Fan Maximum Speed
(FS.MX). On Direct Drive ECM units the fan will run Low Speed
when the compressor is turned on and will run High Speed when
the loader is turned on. The Reduced Cool Fan Speed (F.SPD) is
not used with ECM units. All normal cooling alarms and alerts are
functional. The low ambient outdoor fan test (L.ODF) can be
turned on and off while running the compressor.

Table 4 – Service Test Modesand Submodes Directory

DISPLAY MENU/ .

S U B --- M E N U / . .

NAME

SERVICE TEST

TEST Field Service Test Mode Off/On
INDP Test Independent Outputs

ECON Economizer Position Test 0 to 100%
E.CAL Calibrate Economizer Off/On
PE.1 Powe r Exhaust 1 Test Off/On
PE.2 Powe r Exhaust 2 Test Off/On
ALRM Alarm Relay Test Off/On

FANS Te st F an s

F. SP D Indoor Fan Speed Test 0 to 100%
F. MO D IDF Fan Mode 0to7
IDF.1 Indoor Fan 1 Test Off/On
IDF.2 Indoor Fan 2 Test Off/On
IDF.3 Indoor Fan 3 Test Off/On

COOL Test Cooling

CMP.A Cool A Test Off/On
LDR_A Cir A Loader Test Off/On
F. SP D Reduced Cool Fan Speed 0 to 100%
L.ODF Low Amb ODF Test 0 to 100%

HEAT Te st H eat i ng

HT.1 Heat Stage 1 Test Off/On
HT.2 Heat Stage 2 Test Off/On
F. SP D Reduced Heat Fan Speed 0 to 100%

EXPANDED NAME VALUES

Heating Test

The heating (HEAT) submenu is used to change output status for
the individual heat stages, gas or electric. The fans (FANS) 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. The fan will run at
Supply Fan Maximum speed (FS.MX) when running any heat
output. The Reduced Heat Fan Speed (F.SPD) is not used at this
time. 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,
ConfigurationUNITU.CTL, must be 2 to recognize the
below inputs. Terminal R is the 24vac source for the following:

S Y1 = First stage cooling
S Y2 = Second stage cooling
S W1 = First stage heating
S W2 = Second stage heating
S G = Indoor fan

Dehumidification Control

The HUM terminal can be used on the Field Connection board
when the isolation relay is installed between the MBB and TB.
Humidity Switch configuration, ConfigurationUNITRH.SW,
identifies the normally open or normally closed status of this input
at LOW humidity.

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

48/50LC

11

Remote Occupancy

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

S RMOC = 24 VAC signal input
S R--2 = 24 VAC sourcefor dry contact

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UNITFS.SW, identifies the
normally open or normally closed status of this input when there is
no fire alarm.

S FDWN = 24 VAC signal input

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.

S C--2 = 24 VAC common

48/50LC

S 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
for DCV control. Refer to the Indoor Air Quality operation section
for more information.

sensor input can not be used

2

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 (Configuration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 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.

S 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.

S 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 Thermostat
(ConfigurationUnitU.CTL = 2). The value determines
alternative system staging. See the specific operation sections for
more information. The factory default value is T.CTL =0
(Adaptive).

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. CTL =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. The RAT sensor can allow economizer
differential dry bulb control.

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. 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 humidistat (HUM) input, and what status (normally
open, normally closed) the input is when the space humidity is
LOW.

12

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) defines
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 MODE and Operating Modes MODE.

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 below.

HVAC
Mode

Disabled HVAC Operation

Fan
Only

Cooling

Heating Heating Heating mode

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 table below shows the 8 modesand a brief
description for each.

Mode

Expanded Text Brief Description

Disabled

Ventilation
( f a n --- o n l y )

Cooling Mechanical cooling

Free Cooling Only economizer used for cooling

Unoccupied
Free Cooling

Dehumidification Running advanced dehumidification

Dehum Cooling Running coo ling with advanced dehumidification

Fan

Expanded Text Brief Description

0 OFF When the fan is off

1 Speed 1 P r e --- L o w S p e e d

2 Speed 2 Low Speed

3 Speed 3 P r e --- H i g h S p e e d

4 Max Speed When running at Maximum Fan Speed

5 Ven t When in Ventilation mode and the fan is on

Unit is in test mode or System mode is dis­abled

Fanmayrunforventilation

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

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.

Timed 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 ifoperation of the compressor 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

48/50LC 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 (ConfigurationUNIT
U.CTL = 1), the unit will operate based on discrete 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 (ConfigurationUNITT.CTL ) 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 (Configuration
UNITU.CTL = 2), the unit will try to maintain the Space
Temperature (TemperaturesAIR.TSPT) between the effective
cool and heat setpoints (Run StatusMODEEFF.C and
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COOLMS.TG and
Operating ModesHEATMS.TG) show the remaining time
before allowing the respective mode to be entered.

48/50LC

13

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
OHSP) are active. When the building is in unoccupied mode,
the Unoccupied Cool Setpoint (SetpointsUCSP)andthe
Unoccupied Heat Setpoint (SetpointsUHSP) are active. The
heating and cooling set points are also separated by a Heat--Cool
Set Point Gap (SetpointsGAP) that is user configurable from 2
to 10 degrees F. This parameter will not allow the setpoints to be
set too close together, it will changethe 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 STO.R)sets
the total positive or negative degrees that can be added to the
setpoints. With the slider in the middle, no offset is applied. Moving

48/50LC

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 (Temperatures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 using 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 occur 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 ComfortIDt 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 3rd 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
Normally 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UNITRM.SW = 0) No Switch

2. (ConfigurationUNITRM.SW = 1) Normally Open

Switch

3. (ConfigurationUNITRM.SW = 2) Normally Closed

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GEN.IRM.OC) point will show the status of the
switch.

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 an d 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 (ConfigurationCCNSCH.O

SCH.N) and the Global Schedule Broadcast (Configuration
CCN BRODB.GS).

1. (ConfigurationCCNSCH.OSCH.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
(Configuration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
(Configuration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 (Configuration
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 (Configuration
CCNSCH.OOV.TL). The hours remaining in
override is displayed as Timed Override Hours
(Configuration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)setsthe
type of fan and how it is controlled. These 48/50LC units can
utilize the LEN VFD (FTYP = 1) or ECM (FTYP = 2) fan types.
The Number of Speeds configuration (Configuration →I.FAN
→ECM →NSPD) is used when Fan Type is set for ECM, and tells
the control how many speed outputs to use. 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 control. 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

14

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 without delay on alarm. Fan off
delays are honored when exiting specific HVAC modes. The
Fan-off Delay delays are as follows: Mech Cool (Configuration

→COOL →FOD.C), Elect Heat (Configuration →HEAT
→FOD.E), and Gas Heat (Configuration → HEAT →FOD.G).

Direct Drive Units (FTYP = ECM)

Direct Drive ECM fan units can operate with two or three speeds,
set by the number of fan speeds configuration point (NSPD). Low
Speed and High speed are standard unit speeds, and the Ventilation
Speed is the 3
relays on the main base board (MBB). Indoor Fan Speed Relay 1
(Outputs →FANS →IDF1) controls the low speed command;
Indoor Fan Speed Relay 2 (Outputs →FANS →IDF2) controls
the high speed command; and Indoor Fan Speed Relay 3 (Outputs
→FANS →IDF3) controls the optional vent speed command. The
actual speeds are set by the motor tap in which they are wired to.
For only 2 speed units (NSPD = 2), the vent speed (IDF.3) will not
be used, instead the low speed output will be used during the
ventilation times. Refer to the heating or cooling operation sections
for details on when the fan changes speed, but general operation is
explained below.

Thermostat Control

In thermostat mode, the fan will run vent speed when only the fan
request G in ON. If a cooling request Y1 is ON the fan will be at
low speed. If the cooling request Y2 is ON the fan will be at high
speed. If a heating request W1 or W2 is ON, the fan will run high
speed. If the G call is dropped or was never on with an Y1, Y2,
W1, or W2 call; the fan 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 fan will run vent speed 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 at low or high speed when there are cooling,
heating, or dehumidification running; or if there is an air quality
demand. In general, the fan will run low speed with part load
cooling and high speed any other time. During the unoccupied
period, the fan will operate intermittent. With intermittent fan, the
fan will turn off after a configurable time delay with respect to the
HVAC mode that is ending.

rd

optional speed. These speeds are controlled by the

Belt Drive VFD Units (FTYP = LEN VFD)

Belt drive fan units are equipped with a Variable Frequency Drive
(VFD), which is powered direct from the distribution block and is
always on with power applied. The VFD communicates on the
Local Equipment Network (LEN) bus. When the thermostat or
space sensor control conditions require the fan, the control will
command the VFD to the desired speed with the Commanded Fan
Speed (Outputs →FANS →F.SPD) point. Feedback from the
VFD can be reviewed in the Supply Fan VFD Menu (Run Status
→S.VFD). Refer to the VFD Major Component section for more
information on the VFD (see page 56).
There are 5 speeds that the indoor fan will run at based on the
running mode and demand for conditioning. The five configurable
speeds are:
Supply Fan Maximum Speed (Configuration →I.FAN →FS.MX)
Supply Fan Speed 1 (Configuration →I.FAN →F.SP1)
Supply Fan Speed 2 (Configuration →I.FAN →F.SP2)
Supply Fan Speed 3 (Configuration →I.FAN →F.SP3)
Fan Speed – Ventilation (Configuration →I.FAN →FS.VN).
Fan speed is always calculated by evaluating the current applicable
conditions. Each fan speed “mode” is evaluated independently, and
the highest requested fan speed is used. When first ramping up
from 0%, the fan will run at max speed (FS.MX) for 1 minute.

Refer to the speed configurations below for an overview of usage;
refer to other specific operating sequences for more details on fan
operation during the corresponding mode.

Supply Fan Maximum Speed (FS.MX)

Max speed is the highest fan speed allowed. This is typically 100%
as 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. 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. With a heating
demand, the fan will always run at this speed. When in an IAQ
override condition the fan will run at this speed. When the IAQ
override condition is cleared the speed will go to the next
commanded speed.

Supply Fan Speed 1, 2, and 3 (F.SP1, F.SP2, and F.SP3)

These configurations define the intermittent fan speeds used during
cooling. Supply Fan Speed 2 (F.SP2) is pre set to the optimum
energy efficiency part load speed. Changing this might affect the
overall efficiency of the unit. Supply Fan Speed 1 and 3 (F.SP1
and F.SP3) are pre set to transition the fan during cooling stage up,
and to aid in dehumidification. These 2 speeds can be adjusted in
the field to optimize dehumidification, load balancing, or
efficiency.

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 (Configuration →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 check 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.

Traditional Fan Operation

On units with a belt drive VFD, traditional fan operation can also
be selected. When Smart Fan Control (Configuration → I.FAN →
SMT.F) is set to NO, the fan will operate with simple logic and
run the fan as an electromechanical unit would. When in
ventilation mode, the fan will run at the Fan Speed – Ventilation
(FS.VN) fan speed. When cooling requests the fan, the fan will run
at Supply Fan Speed 2 (F.SP2). Supply Fan Maximum Speed
(FS.MX) will be active anytime 2 cooling stages are requested or
running. In free cooling the fan will run at F.SP2 until the damper
is 100% for 4.5 minutes when the fan will ramp to FS.MX. When
heating request the fan, the fan will run at FS.MX. Advanced
dehumidification function will not be allowed to run. The fan will
still honor respective off delays.

Cooling Operation

The 48/50LC unit’s cooling operation consists of: demand and
mode determination, staging request to satisfy the demand, and
handling a request with the unit’s resources. These resources can
include compressor, a loader, an economizer, and fan speed based
on options. This section covers mechanical cooling. For
economizer and dehumidification refer to their respective sections.
In general, 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 →MODE →HVAC=3) has
4 different expandable texts: Cooling, Free Cooling, Unoccupied

15

48/50LC

Free Cooling, and Dehumidification. These are all part of a general
cooling mode and resemble the specific type of cooling that being
performed at any given time. All types of cooling are still performed
under the generalcooling function, and theexpanded textis 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
dehum 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 dehum demand exists and a heat demand (W1, W2) occurs,
the unit will end cooling. The cooling mode can not officially end
until the compressor is 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 dehum demand. The unit will remain in
cooling for at least one minute and until the demand is dropped or
if any of the above conditions turn false. If only a dehum demand

48/50LC

exists and the heat demand becomes greater than the Dehum Heat
Setpoint Deadband (Setpoints →RH.HB), the unit will end
cooling. The cooling mode can not officially end until all
compressors are off.

Cooling Staging Control

Once the unit is in a cooling mode, it must decide what the demand
is and how to satisfy. If an economizer is installed and can be used
for cooling (Operating Modes →COOL →OK.EC= Yes), the unit
will use it first (see economizer section for its operation). If the
economizer cannot be used or additional cooling is needed, a
mechanical cooling check is performed. OK to use Compressors?
(Operating Modes →COOL →OK.MC), will be set to yes when
the compressor is enabled and not locked out. Based on the unit
control configuration, requested cooling stages (Run Status
→COOL →REQ.C) will be determined then passed 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.CTL) is set to 1, 2, or 3 and the unit cannot use the
economizer for free cooling. If Thermostat Control (T.CTL) is set
for 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 (Configuration →COOL →C.INC) or
the Cool Stage Decrease Time (Configuration →COOL
→C.DEC) has to expire before another stage can be added or a
stage can be subtracted. The Supply-Air Trend (Operating Modes
→COOL →SA.TR) decides if the 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 →COOL →SAT
→SAT.U), the requested stages will not be allowed to increase. If
at any time the SAT falls below the Minimum Supply Air
Temperature Lower Level (Configuration →COOL →SAT
→SAT.L), the requested stages will 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 might cycle rapidly, slowed only
by its minimum on and off-time requirements.

T.CTL=1or2(1StageY1or2stageY1)
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)
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 two stages. Y1 and Y2 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
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 Status →COOL →DMD.C).The
control tries to anticipate the change in the space because of its
current stage status. This anticipation is based on the Supply-Air
Trend (Operating Modes →COOL →SA.TR) and the Cool
Demand Trend (Operating Modes →COOL →TRD.C).These
trends will 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 Cool Stage Increase Time
(Configuration →COOL →C.INC) or the Cool Stage Decrease
Time (Configuration →COOL →C.DEC) has to expire before
another 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 (Configuration →COOL
→SAT →SAT.U), the requested stages will not be allowed to
increase. If at any time the SAT falls below the Minimum Supply
Air Temperature Lower Level (Configuration →COOL →SAT
→SAT.L), the requested stages will 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 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 request stages, the compressor
control determines what is available or running and tries to provide
stages for what is requested. The availability of the compressor or
loader depends on time guards, circuit diagnostics, and outdoor
temperature. The Circuit A Lockout Temp (Configuration
→COOL →CA.LO) configuration set the outdoor temperature in
which the compressor is allowed to run down to. Any time the
outdoor ambient falls below 10 degrees, the loader will be locked
on when the compressor is turned on. The outdoor ambient must
then rise above 15 degrees before the compressor will be allowed
to run without the loader. Timeguard A (Run Status →COOL
→TG.A) and Timeguard Loader (Run Status →COOL →TG.L)
display the time the compressor or loader has before it is available
for use. Circuit diagnostic tests are performed during operation
which may or may not allow the compressor or loader to be used.
The available stages at any given time are displayed as Available
Cooling Stages (Run Status →COOL →AVL.C). The actual
stages running at any given time are displayed as Actual Cooling
Stages (Operating Modes →COOL →ACT.C). Compressor A

(Run Status →COOL →CMP.A), and Circuit A Loader (Run
Status →COOL →LDR.A) are displayed on when the respective

output is turned on. There are time guards to protect the
compressor, Compressor Min On Time (Configuration →COOL

→MRT.C) and Compressor Min Off Time (Configuration
→COOL →MOT.C) apply before the compressor or loader can be

turned back on or turned off.

Outdoor Fan Control

The outdoor fan is controlled electromechanically with the
compressor contactor, not directly by the control system. Refer to

16

specific unit wiring diagram and or service manual for details on
how the outdoor fan operates. In general, the outdoor fan will be
on full speed when the compressor is turned on. The control
system can override the speed of the outdoor fan for low ambient
operation. When the Outdoor Air Temperature (Temperatures

→AIR.T →OAT) falls below the Low Ambient ODF Setpoint
(Configuration →COOL →LA.SP) the Low Ambient Outdoor

Fan relay (Outputs →COOL →L.ODF) will be energized. When
this happens the outdoor fan will reduce its speed to the pre-set low
ambient RPM. The ambient must then rise 5_F above LA.SP to
allow full speed on the outdoor fan.

Indoor Fan Smart Staging Control

On direct drive fan units the fan will follow simple control. With
one stage of cooling running, the fan will run the low fan speed.
With 2 stages of cooling running, the fan will run high fan speed.
On belt drive VFD fan units the fan will be controlled as described
below. Refer to the Fan operation section for other details on fan
operation.

The indoor fan speed will change throughout cooling operation
based on cooling demand, run time, supply air temperature, and
refrigerant suction temperature. With only one stage of cooling
running the fan will run at Supply Fan Speed 1 (F.SP1) and then
Supply Fan Speed 2 (F.SP2). With 2 stages of cooling running the
fan will run at Supply Fan Speed 3 (F.SP3) and then Supply Fan
Maximum Speed (FS.MX). The fan will wait the Fan Transition
Time (Configuration →Cooling →FTT) between fan speeds 1 and
2 or 3 and max, unless the supply air overrides it. The supply air
temperature (SAT) can override the FTT if it falls below the
Minimum Supply Air Temperature Upper Level (SAT.U) or if its
trend (SA.TR) anticipates a need for more air. The fan will be
allowed to run F.SP3 if the SAT is limiting second stage cooling.
Maximum Speed (FS.MX) will be allowed too after running F.SP3
for halfofFTT.

Any time during cooling after the compressor has been on for 2
minutes, a low refrigerant suction temperature can override the fan
speed to the Supply Fan Maximum Speed (FS.MX). This will
occur if the Sat. Suction Temp A (Temperatures →REF.T

→SST.A) falls below the Fan Low Suction Temp (Configuration
→COOL →SST →FLSU) for one minute. If both cooling stages

are on with the fan at Max speed and the low suction condition
occurs for 1 minute, then the second cooling stage will be
removed. The Fan Low Suction State (Operating Modes →COOL
→LSST) will be set to yes. Cooling stage 2 will be allowed back
on after the Compressor Min Off Time (MOT.C), and the Fan Low
Suction State can be cleared after 5 minutes of running without the
low suction condition. If the suction returns low within the 5 min,
then a stage down of cooling stage 2 will occur again. If this cycle
happens 3 times in a row, the Full Load Lockout (Operating
Modes →COOL →FLLO) will be set to yes and the second
cooling stage will not be allowed back on until the cooling demand
is removed.

Dehumidification Control

Dehumidification operation requires installation and configuration
of either a space relative humidity sensor or a relative humidity
switch input. Space Humidity Switch (Configuration →UNIT
→RH.SW) set to 1 for use of a normally open switch, or 2 for
normally closed switch. The switch is wired to the field connection
terminal board terminals R-2 and HUM. RH Sensor on OAQ Input
(Configuration →UNIT →RH.S) set to Yes for use of a 4 to 20
mA output RH sensor wired to field connection terminal board
terminals LPWR and SPRH (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→AIR.Q→H.20M) sets the % display for a
20mA input from the relative humidity sensor.

IMPORTANT: The HUM terminal on the field connection board
is not wired and requires a isolation relay with gold plated contacts

to wire to MBB J9-5 and 6. The RH sensor input requires the ECB
to be installed if not already.

Dehumidification is a cooling mode function. When using a
humidistat or switch input, the demand for dehumidification is
seen as Space Humidity Switch (Inputs →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
(Inputs →AIR.Q →SP.RH) value compared to the Space RH
Setpoint (Setpoints →RH.SP). If the Space Humidity Sensor
(SP.RH) value is above the Space RH Setpoint (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 (Setpoints →RH.DB), then dehumidification is no
longer needed. If the unit is configured for space sensor control
(Configuration →UNIT →U.CTL = 3), then the setpoint Dehum
Heat SP Deadband (Setpoints →RH.HB) applies. This
configuration sets the offset above the heating set point at which a
unit in dehum mode will turn off. This is a protection against over
cooling the space and causing a heat demand. There are three types
of dehum control set by the configuration Dehum Control Type
(Configuration →COOL →DHUM). Dehum Control is factory
defaulted to 0 which is No Control meaning that any dehum
demand is ignored.

NOTE: When there is a dehumidification demand, the economizer
damper position is limited to its minimum damper position

(Operating Mode →ECON

Max Dehum (DHUM = 1)

When the Dehum Control Type (DHUM) is set to (1) Max dehum,
the control will try to satisfy the dehum demand. The Fan
Transition Time (FTT) will not be utilized nor the Supply Air
Upper Level (SAT.U). The Supply Air Lower Level (SAT.L) limit
will be honored while running the cooling stages. Fan Low
Suction (FLSU) will be handled per below.

With only a dehum demand, the control will start with 1
cooling at the Supply Fan Speed 1 (F.SP1). When stage 2 is
available it too will be requested leaving the fan at F.SP1. If the
Sat. Suction Temp A (SST.A) falls below the Fan Low Suction
Temp (FLSU) for one minute the fan will step up to Supply Fan
Speed 2 (F.SP2) for one minute. If SST.A still falls below FLSU
for one minute the fan will run at Supply Fan Speed 3 (F.SP3). If
the low suction still occurs, the second cooling stage will be
removed and the fan set back to F.SP1. If the low suction still
persists, then the fan will run at F.SP2 until the low suction alarm
trips out the circuit or the dehum call is satisfied.

With a dehum call and 1 stage of cooling being requested, the
control will run 1 stage of cooling at Supply Fan Speed 1 (F.SP1).
If the Sat. Suction Temp A (SST.A) falls below the Fan Low
Suction Temp (FLSU) for one minute the fan will step the fan to
F.SP2, if it continues, the fan will ramp to Supply Fan Maximum
Speed (FS.MX).

If dehum and max cooling is being requested, the control will run
both cooling stages at Supply Fan Speed 2 (F.SP2). Fan Low
Suction Temp (FLSU) will follow normal cooling operation.

Max Comfort (DHUM = 2)

When the Dehum Control Type is set to (2) Max Comfort, the
control will try to satisfy the demand while minimizing the cold air
dump. The Fan Transition Time (FTT) will not be utilized nor the
Supply Air Upper Level (SAT.U). The Supply Air Lower Level
(SAT.L) limit will be honored while running the cooling stages.
Fan Low Suction (FLSU) will be handled per below.
With only a dehum demand, the control will run 1 stage of cooling
at Supply Fan Speed 1 (F.SP1). If Supply Air Temperature (SAT)
falls below the Comfort SAT Setpoint (Setpoints →CCSP),thefan
speed will be raised to Supply Fan Speed 2 (F.SP2) for one minute
and so on up until Supply Fan Maximum Speed (FS.MX) is
reached or the SAT raises above the Comfort SAT Setpoint

→EC.MP).

st

stage of

48/50LC

17

(CCSP). If running FS.MX for one minute and the SAT is still
lower than the comfort setting, the cooling stage will be removed
for 10 min before trying again. Fan Low Suction Temp (FLSU)
will not be honored however the circuit will be allowed to trip on
low suction alarm.

With a dehum call and 1 stage of cooling being requested, the
control will run 1 stage of cooling at Supply Fan Speed 1 (F.SP1).
If the SAT falls below CCSP then the fan will raise one speed
every minute until Supply Fan Speed 3 (F.SP3) or SAT rises above
the CCSP. If SAT stays above CCSP plus 5 degrees the control
will be allowed to run 2
Temp A (SST.A) falls below the Fan Low Suction Temp (FLSU)
for one minute the control will drop the request for the second
stage cooling. If SST.A then falls below FLSU for one minute, the
fan will ramp to Supply Fan Maximum Speed (FS.MX).

If dehum and max cooling is being requested, the control will run
both cooling stages at Supply Fan Speed 2 (F.SP2). If the SAT
falls below CCSP then the fan will raise one speed every minute
until Supply Fan Maximum Speed (FS.MX) or SAT raises above
the CCSP. Fan Low Suction Temp (FLSU) will follow normal
cooling operation.

nd

stage of cooling. If the Sat. Suction

Heating Operation

48/50LC

The 48/50LC unit’s heating operation consists of: demand and
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
→HEAT →HT.TY) configuration will be factory set to 1 for gas
units, 2 for electric heat units with heaters installed, and 0 for
electric heat units without heat installed. In general, 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.

Supply-Air Temperature Sensor (SAT)

The SAT Heat Mode Sensing (Configuration

→HEAT→SAT→SAT.H) informs the unit that the supply air
sensor has been relocated downstream of the heat section. This
configuration affects the Supply Air Temperature (Temperatures
→AIR.T →SAT) value displayed as listed below.

When SAT.H = DSBL, the Supply Air Temperature
(Temperatures →AIR.T →SAT) value on the Scrolling Marquee
and the CCN tables will be forced to zero when heat outputs come
ON 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
(Temperatures →AIR.T →SAT) sensor reading is displayed at the
Scrolling Marquee and the CCN tables during heating mode. This
setting should only be used if the original SAT sensor wires are
removed from the field connection terminal board and replaced by
an accessory SAT sensor located in the supply duct downstream of
the heat section. There are then two supply air temperature limits
that become active, the Maximum SAT Lower Level
(Configuration →HEAT →SAT →SAM.L) the Maximum SAT
Upper Level (Configuration →HEAT →SAT →SAM.U).Any
time the 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 cannot 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
→HEAT →H.DEC). If 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.

Indoor Fan Control

On direct drive fan units the fan will follow simple control. With
any heating stages gas or electric, the fan will run high fan speed.

On belt drive VFD fan units the fan will always run at Supply Fan
Maximum Speed (FS.MX) during heat mode.

Heating Mode Control

The heating HVAC mode (Run Status →MODE →HVAC=4)
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
Temperature (Temperatures →AIR.T →OAT) must be less than
the Heating Lockout Temp (Configuration →HEAT →HT.LO).
Heat OAT Lockout (Run Status →MODE →H.LOC) displays
when heat is locked out on outdoor temperature and therefore
cannot allow heat mode. The control will display if it is ok to select
the heating mode (Operating Modes →HEAT →OK.HT= Yes).

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 (IGC.F) is dropped.

Space Sensor Control

For the unit to enter heating mode, five 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
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 (IGC.F) is dropped.

Staging Control

Once the unit is in a heating mode, it must decide what the demand
is and how to satisfy. Based on the unit control configuration,
requested heating stages (Run Status →HEAT →REQ.H) 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.CTL) is set to 1, 2, or 3. Adaptive control is used if
Thermostat Control (T.CTL) is set for 0.

T.CTL = 0 (Adaptive Control)
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 →H.INC) or the Heat
Stage Decrease Time (Configuration →HEAT →H.DEC) has to
expire before another stage can be added or a stage can be
subtracted. If at any time the Supply-Air Temperature (SAT) falls
below the Maximum Supply Air Temperature Lower Level
(Configuration →HEAT →SAT →SAM.L), the requested stages
will not be allowed to increase. If at any time the SAT falls below
the Maximum Supply Air Temperature Upper Level
(Configuration →HEAT →SAT →SAM.U), the requested stages
will be reduced by one without honoring H.DEC.

T.CTL = 1, 2 or 3 (Traditional thermostat control)
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

18

Status →HEAT →DMD.H). The control 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 →HEAT →TRD.H). This trend will 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 →HEAT →H.INC)
or the Heat Stage Decrease Time (Configuration →HEAT
→H.DEC) has to expire before another stage can be added or a
stage can be subtracted. If at any time the Supply-Air Temperature
(SAT) falls below the Maximum Supply Air Temperature Lower
Level (Configuration →HEAT →SAT →SAM.L), the requested
stages will not be allowed to increase. If at any time the SAT falls
below the Maximum Supply Air Temperature Upper Level
(Configuration →HEAT →SAT →SAM.U), the requested stages
will be reduced by one without honoring H.DEC.

Heat Relay Control

The heat relay control is responsible for energizing or
de-energizing the heat stage relays and works hand and 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 the heat installed, how
many stages, and time guards. The type of Heat Installed
(Configuration →HEAT →HT.TY) must be set for gas or electric
for any stages to be available. The Number of Heat Stages
(Configuration →HEAT →N.HTR) configuration tells the control
how many heat relays can be used. Heat Stage 1Timeguard (Run

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

has before it is available for use. The available stages at any given
time are displayed as Available Heating Stages (Run Status
→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 Status →HEAT
→HT.1) and Heat Stage 2 Relay (Run Status →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 →HEAT →MRT.H) and Heat Minimum Off
Time (Configuration →HEAT →MOT.H) apply before a heat
relay can be turned back on or turned off.

Integrated Gas Controller (IGC) – 48LC Units Only

The heat staging is determined as described above and the
Integrated Gas Controller (IGC) initiates the gas heat module
start-up. The Integrated Gas Controller (IGC) minimum on-time of
1 minute will be followed even if Heat Minimum On Time
(Configuration →HEAT →MRT.H) is lower and during Service
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 (Configuration →HEAT
→FOD.G) unless power is reset to the control. 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 above the gas section in the control box.

When the control energizes Heat Stage 1 Relay (Run Status
→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 and 45 seconds
after ignition occurs, the indoor-fan request IGC Fan Request
(Inputs →GEN.I →IGC.F) will be energized. 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 →HEAT
→HT.2), 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.

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 (OutputsECONEC.CP) on the Economizer Control
Board (ECB). Feed back from the economizer actuator is output to
the ECB and is displayed as Econo Actual Position (Outputs
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)

ol

Contr

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.

19

48/50LC

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--T24TSTMN%.

48/50LC

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--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:

S 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.

S If the actuator jammed while opening (i.e., reported position <

commanded position), a “not economizing when it should” alert
shall be logged.

S 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:

S If the actuator jammed while opening, when ECONOPOS >

jammed position the alerts shall be cleared.

S 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

actuator

NO – do not attempt to detect and log mechanically

disconnect 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” – minimum
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” – minimum
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.” – minimum
position below which tests for a mechanically disconnected
actuator will not be performed. For example, if the actuator moves
entirely within the range 0--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--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

20

ET.MX (T24TSTMX) – “T24 Test Maximum Pos” – maximum
position above which tests for a mechanically disconnected
actuator will not be performed. For example, if the actuator moves
entirely within the range T24TSTMX --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--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

Economizer Actuator Communication

The economizer actuator used with the 48/50LC 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ECONE.CTL) determines 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ECONE.CTL)
configuration parameter is changed.

E.CTL = 1 or 2 (Digital/Position or Digital/Command)

When Economizer Control Type (Configuration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ECONC.ANG) is provided 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 (ConfigurationECONM.ANG). During this
digital control, the Economizer 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 running 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 StatusECONEC.MP). This
minimum position can be effected by the indoor fan speed and
indoor air quality.

On Direct Drive ECM units, the economizer minimum position
will be equal to the ECON MIN at MAX Fan Speed
(ConfigurationECONMP.MX), when running High Fan
Speed, ECON MIN at Low Fan Speed (Configuration
ECONMP.LO), when running Low Fan Speed, or ECON
MIN at VENT Fan Speed (ConfigurationECON MP.VT)
when running Ventilation Fan Speed, unless Indoor air quality
requests something different.

On Belt Drive VFD units, to maintain a constant airflow 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. 6.

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

sensor the Economizer minimum position will be recalculated

CO

2

basedontheCO

sensor or return duct CO2sensor and outside air

2

level of the return and/or outside air. On VFD

2

units the fan speed will also be used in recalculating minimum
position, as shown in Fig. 6. When the Commanded Fan Speed
(F.SPD) is less than the Supply Fan Maximum Speed (FS.MX) the
damper will operate in the shaded area of Fig. 6 based on the IAQ
Level (IAQ). See the Indoor Air Quality (IAQ) section (starting on
page 23) for more details on Demand Control Ventilation (DCV).

sensors for

2

48/50LC

Economizer Position %

100

75

50

25

0

0 100 50 75 25 20

Minimum
Fan Speed

MP.25

MP.50

MP.25 DCV

MP.75

MP.50 DCV

MP.75 DCV

Fig. 6 -- Minimum Damper Position Curve (on units with multiple fan speeds)

21

EC.MX

MP.MX

AQ.MN for DCV

Fan Speed %

C11544

The shape of the Economizer Minimum Position vs. Fan Speed
curve is determined by the configuration parameters: Econ Min at
25% Fan speed (ConfigurationECONMP.25), Econ Min at
50% Fan speed (ConfigurationECONMP.50), Econ Min at
75% Fan speed (ConfigurationECONMP.75) and Econ Min
at Max Fan speed (ConfigurationECONMP.MX). These
configurations are preset at the factory for default purposes. The
Econ Min at Max Fan Speed (MP.MX) should be changed based
on the air balance 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 (Configuration

ECONMP.25), Econ Min at 50% Fan speed (Configuration
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 (Configuration
ECONMP.MX) outside air CFM through the economizer

48/50LC

outside air dampers. The default calculations programmed into the
LC controls are based on a side shot economizer at 400 CFM/TON
Supply Air flow with negative 0.25 in H2O pressure 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 Status
MODEOK.EC = Yes) if the supply air temperature sensor
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)orlessthanthe
configured Econo Cool Lo Temp Limit (Configuration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 (ConfigurationAIR.QOAQ.L).
Any one of these lockouts will disable economizer free cooling.

When the economizer is available for free cooling and the
compression is not on, the damper will open from minimum
position based on the supply air temperature (SAT) to provide free
cooling. In thermostat control mode, a Y1 command will utilize the
Low Cool SAT Setpoint (Setpoints → LCSP) to control the
economizer, and a Y2 will utilize the High Cool SAT Setpoint
(Setpoints → HCSP). In Space Sensor Control, the LCSP and
HCSP points are utilized according to Table 5.

If the control senses low suction pressure when the economizer is
also providing cooling, the maximum allowable economizer
position will be reduced. The Bottom Stage Max Econo
(Configuration→ECON→E.MXB) configuration sets the position
the damper will move to. Factory default configurations have been
qualified over a large range of conditions and should only be
changed with care.

Table 5 – 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 --- L o w C o ol S e t Poi n t
SAT --- S u ppl y --- A i r T emp e r a t ure

COOL DEMAND

(F)

NEXT SAT

SET POINT

Direct Drive Units

During free cooling the fan will run at Low Speed. After the
economizer reaches 100% (or Max) for 5 minutes, the fan will be
changed to High Speed. The fan will drop back to low speed if the
damper position falls below 75%. The compressor will be allowed
for use after the fan and economizer are 100% (or Max) for 5
minutes. Once compression is turned on the economizer and fan
will remain at 100% until the call for cooling is removed.

Belt Drive VFD Units

During free cooling the fan will start at Speed 1. After the
economizer reaches 100% (or Max) for 1 minute, the fan will be
changed to Speed 2. If the damper remains at 100% the speed will
increase every minute until maximum speed. If the damper starts to
close the current running fan speed will be locked in until cooling
call is removed. The compressor will be allowed for use after the
fan and economizer are 100% (or Max) for 5 minutes. Once
compression is turned on the economizer and fan will remain at
100% until the call for cooling is removed.

Air--Side Economizer High Limit Switches Control

Differential Dry Bulb Cutoff Control

Econo Diff DBulb Lockout (Operating Modes-->ECON-->D.LOC)
occurs when Diff Dry Bulb Control is enabled
(Configuration-->ECON-->DF.DB != DISABLE). 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:

DF.DB

(DIFFBULB)

DISABLE N/A NO

R A T --- 0

R A T --- 2

R A T --- 4

R A T --- 6

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
(SetpointsOHSP) using only the economizerwhen the conditions
in the building and the outdoors are suitable, during unoccupied
periods. Three different configurations define this algorithm:
Unoccupied FreeCooling (ConfigurationECONUEFC), Free
Cooling Preoccupancy Time (ConfigurationECONFC.TM),
and FreeCool Low Temp Limit(Configuration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.

OAT/RAT

Comparison

OAT>RAT YES

OAT<=RAT NO

O A T > R A T --- 2 YES

OAT<=RAT ---2 NO

O A T > R A T --- 4 YES

OAT<=RAT ---4 NO

O A T > R A T --- 6 YES

OAT<=RAT ---6 NO

D.LOC

(DFDBLOCK)

22

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 (Temp era tureAIR.TOAT)islessthanFC.LO.

Power Exhaust (Direct Drive ECM 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 and the fan is running High
Speed. Power Exhaust 2 will turn on when the economizer position
is greater than the value of ConfigurationECONPE.2 and the
fan is running High Speed. There are small time delays to ensure
that rapid cycling does not occur.

When running Low Fan speed or Ventilation Fan Speed, the Power
Exhaust setpoints will be offset based on the difference between Econ
Min at Max Fan Speed (MP.MX) and the Econ Min at Low Fan
Speed (MP.LO) or Econ Min at Ventilation Fan Speed (MP.VT).

Power Exhaust (Belt Drive VFD units)

To enable power exhaust, set Power Exhaust Installed
(ConfigurationECONPE.EN) to YES. Both power exhaust
fans are wired together and are controlled by the configuration
Power Exhaust Stage1 CFM (Configuration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 (Outputs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 calculated outside air CFM falls below Power Exhaust Stage1
CFM (PE1.C). The Power Exhaust Stage2 CFM (Configuration
ECONPE2.C) is not currently used on these products.

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
in parts per million (ppm). Outdoor air quality may be measured
with a CO

2

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-installed indoor air
quality CO

sensor may be mounted in the return duct or directly

2

in the occupied space, per job requirements. The indoor air quality
modes of operation can be affected by configurations for indoor air
quality sensor (ConfigurationAIR.QIA.CF), indoor air
quality switch (ConfigurationAIR.QII.CF), outdoor air
quality sensor (ConfigurationAIR.QOA.CF) and other
related fan and 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 whose measurements are displayed

2

sensor for indoor-outdoor differential demand

Sensor Value at 4mA (ConfigurationAIR.QI.4M)andIAQ
Sensor Value at 20mA (ConfigurationAIR.QI.20M).

IA.CF = O (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I.FANFS.MX) and the 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 Control
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AIR.QAQ.MN), while the higher is
referredtoastheEconMinatMaxFanSpeed
(ConfigurationECONMP.MX). The Econo Min IAQ Position
(AQ.MN) should be set to an economizer position that brings in
enough fresh air to remove contaminates and CO

generated by

2

sources other than people while fan is running at maximum speed.
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

generated by all sources including people when the indoor

2

48/50LC

fan is operating at the Supply Fan Maximum Speed
(ConfigurationI.FANFS.MX). The Econ Min at Max Fan Speed
(MP.MX) value is the design value for maximum occupancy.

The ComfortLink control 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AIR.QAQD.L). When the differential
between IAQ and OAQ reaches AQ Differential High
(ConfigurationAIR.QAQD.H), the economizer position 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 (AQ.MN) in a linear manner as shown in Fig. 7.
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 (Outputs
FANS F. S P D ). (See Fig. 6.) The Econ Min IAQ position
(AQ.MN) is offset based on fan speed and the minimum positions
at different fan speed configurations.

ECON MIN

AT MAX

FANSPEED

POSITION

(MP.MX)

2

MINIMUM

IAQ

DAMPER

POSITION

(AQ.MN)

.

2

VENTILATION FOR PEOPLE

INCREASING VENTILATION

VENTILATION FOR SOURCES

100 700 INSIDE/OUTSIDE CO

AQ
DIFFERENTIAL
LOW (AQD.L)

AQ
DIFFERENTIAL
HIGH (AQD.H)

DIFFERENTIAL

2

C11476

Fig. 7 -- Economizer Minimum Position

23

IA.CF = 2 (Override IAQ)

When IA.CF = 2, the IAQ algorithm maintains the damper at Econ
Min at Max Fan Speed (ConfigurationECONMP.MX)when
the indoor fan speed is at Supply Fan Maximum Speed
(ConfigurationI.FANFS.MX) or along the curve on Fig. 6
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AIR.QAQD.H).
The IAQ Override Position (ConfigurationAIR.QOVR.P)
sets the damper position during override. The economizer
damper will return to the Econ Min at Max Fan Speed (MP.MX)
or MP.MX curve at other 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 unoccupied, the
economizer position will be zero. The damper position may

48/50LC

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 (ConfigurationECON

MP.MX), Econo Min IAQ Position (ConfigurationAIR.Q
AQ.MN) and the economizer minimum position and DCV

minimum position curves in Fig. 6 and 7 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
are considered normal. The IAQ switch input is defined by 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 corresponding 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 Control 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 operating at Supply Fan
Maximum Speed (FS.MX). If the fan speed is modulating, see Fig.
6 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

levels

2

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 different range, the

2

ppm display range must be reconfigured by entering new values
for the OAQ Sensor Value at 4mA (ConfigurationAIR.Q

O.4M) and OAQ Sensor Value at 20mA (Configuration
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 control

2

ventilation (DCV).

OA.CF = 1 (DCV)

The outdoor air quality sensor analog input is the value of OAQ
for demand control 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

2

for the OAQ Lockout Limit (Configuration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
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.
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 at
the ventilation speed whenever the building is occupied and
IAQ/OAQ differential is greater than the Fan On AQ Differential
(Configuration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
occupied 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 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.

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 at
the ventilation speed whenever the building is occupied and IAQ is
high. The indoor fan will turn off when the IAQ returns to normal.

.

2

24

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.

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UNIT.

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 TC STHEAT

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:

S Unit is in unoccupied state.
S Next occupied timeis valid.
S Current time of day is valid.
S 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

temperature)*TCS.H
When the Start Bias Time is greater than zero the algorithm will

subtract it from the next occupied time to calculate the 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)RConfiguration

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. See Appendix A.

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B.TIM)

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B.OAT)

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B.GS)

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B.ACK)

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SCH.N)

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
broadcas t its internal time
schedule (B.GS)tothenetwork
and this is the global schedule
number it is broadcasting. If this
is the case, then the control still
follows its internal time
schedules.

Accept Global Holidays? (SCH.OHOL.G)

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OV.TL)

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OV.EX)

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.

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25

SPT Override Enabled? (SCH.OOV.SP)

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.

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 Status
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).

48/50LC

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CCNLDSHS.GRP

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CCNLDSHR.MXC

This configuration tells the unit the maximum cooling stages
allowed to be on during a redline condition.

ConfigurationCCNLDSHS.MXC

This configuration tells the unit the maximum cooling stages
allowed to be on during a loadshed condition.

ConfigurationCCNLDSHR.MXH

This configuration tells the unit the maximum heating stages
allowed to be on during a redline condition.

ConfigurationCCNLDSHS.MXH

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COOLLMT.C) and HSTGLIMT
(Run StatusHEATLMT.H), respectively. In 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)isusedtoshowif
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MODEHV.DN) 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).

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 ComfortLink
unit by the Linkage Coordinator is as follows:

S Reference zone temperature
S Reference zone occupied biased heating and cooling set points
S Reference zone unoccupied heating and cooling set points
S 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:

S Operating mode -- Cooling, Heating, Free Cooling, Fire

Shutdown Evacuation, or Off

S Supply--air temperature
S 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PID. These values have been field tested 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.

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COOLRST.C) with no detectable problems
before the strike counter will be reset to zero. Default value is
5 minutes.

26

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COOLALM.N on display,
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 between
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
(ConfigurationALM.O). Setting a configuration to YES will
result 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.

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 6.) 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:

S 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.

S Cooling and heating loads are satisfied.
S Programmed occupancy schedule.
S General power failure.
S Tripped 24-volt transformer circuit breakers.
S Blown fuse or circuit breakers
S Unit is turned off through the CCN network.
S If supply-air temperature is less than the Minimum SAT Lower

Level (SAT.L) configuration value, unit cannot cool.

S If outdoor-air temperature is less than the Compressor Lockout

Temperature (CA.LO) configuration value, unit cannot cool.

S 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 Code T051 (without Current Sensor)

This alert can only be activated if set to Diagnose Compressor
Safety (Configuration COOL D.CMP = Yes). There are 4
different texts for this 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 marquee
or navigator to expand the T051 alert will show you one of the
below alerts. Make sure the expanded text is read correctly before
troubleshooting.

S Compressor Safety T

This alert occurs when the respective compressor has been running
for 25 sec and the Saturated Suction Pressure (Pressures SSP.A)
reflectsa change in compressor operation. A change in compressor
operation is when the SSP changes more than the Maximum
Suction Change configuration (Configuration COOL
MX.SA) in a two second window while running the compressor
and persists for 40 seconds. This alert can also occur when the
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 circuit. This alert resets 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 relay on the MBB. If one of these opens
during compressor operation, the compressor stops causing the
control to activate this alert.

S Compressor Detected After Turnof

This alert occurs when the compressor is turned off but the
Saturated Suction Pressure (Pressures SSP.A) does not reflect a
shutdown. When shutting down the compressor suction pressure
must rise more than Maximum Suction Change configuration
(Configuration COOL MX.SA) within the first 10 seconds
and stay above it. When this occurs, the control turns off the
compressor relay, 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.

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27

Alert Codes T051 (with Current Sensor)

This alert can only be activated if Current Sensing A1 is enabled
(Configuration COOL CS.A1 = Enabled). There are 4 different
texts for the 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 marquee or navigator to
expand the T051 alert will show you one of the below alerts. Make
sure the expanded text is read correctly before troubleshooting.

S Compressor Safety T

This alert occurs 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 circuit.
This alert resets 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.

S Compressor Detected After Turnof

This alert occurs when the Current Sensor (CS) detects current when
the compressor should be off. When this occurs, the control turns off

48/50LC

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 Code T064 -- Circuit Saturated Condensing Temp
Thermistor Failure

This alert occurs 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 -- Circuit Saturated Suction Temperature
Thermistor Failure

This alert occurs when the unit’s suction transducers are 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.

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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 – Circuit Suction Pressure Transducer
Failure

This alert occurs 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 - Compressor Current Sensor Failure

This alert can only occur if the unit is configured to have
compressor current sensor (
This is not factory installed so would have to be installed in the
field and configured accordingly. This alert occurs when the output
of the current sensor (CS) is a constant high value. This alert resets
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 – Circuit Loss of Charge

This alert has “Service Test” text that will be displayed if the alert
occurred during service test. This alert occurs 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. This alert only
occurs when the compressor is OFF because the low refrigerant
pressure alarms (alert T133) handle this situation when the
compressor is operating.

Alert Codes T126 -- Circuit High Discharge Pressure

This alert has“Service Test” text that will be displayed if the alert
occurred during service test. This alert occurs when alert T051 is
active while the appropriate condensing temperature is greater than
150_F. This alert 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 Alert T051for diagnostic procedure.

Alert Codes T133 -- Circuit Low Refrigerant Pressure

This alert has “Service Test” text that will be displayed if the alert
occurred during service test. This alert occurs when the compressor
is operating and the evaporating temperature (converted from the
suction pressure) is less than configured low suction control levels,
Configuration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 minutes),
SST.2 (for 4 minutes), or SST.3 (for 3 minutes when using 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 outdoor temperature is above

Configuration→COOL→CS.A1).

28

40_F. All the above timers will reset if the suction temperature rises
above SST.O for 1 minute. This alert causes a strike for the circuit.
If the OAT is less than 10_F, the circuit will shut down without a
strike. This alert activates 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 -- Circuit Failure to Pressurize

This alert has “Service Test” text that will be displayed if the alert
occurred during service test. This alert occurs 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 TimeClock 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.

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 -- CircuitDown due to Failure

This alarm has “Service Test” text that will be displayed if the
alarm occurred during service test. This alarm occurs 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.

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.

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UNITFS.SW. 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, theswitch might be open or
closed. The configuration for this switch input can be found at
variable ConfigurationUNITFL.SW. Verify that the
configuration is set correct, 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.

S 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 ConfigurationUNITFN.SW.Verifythat
the configuration is set correctly. Verify the wiring and fan status
switch. The hose should be connected to the high side of the

29

48/50LC

switch. If the IDF is configured to shut down the unit when this
alarm occurs (Configuration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.

S Fan Status Switch Off, Fan Contactor On

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UNITFN.SW. Verify 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 theunit down when this alert occurs
(ConfigurationI.FANIDF.F = YES), then this alarm can
only be reset manually and the unit is shut down. If the IDF is

48/50LC

not configured to shut the unit down when this alert occurs
(IDF.F = NO), then this alert resets automatically and no specific
control action is taken.

Alert Code T410

S 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.

S 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 beleft 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 are10 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.

S Economizer Damper Actuator Out of Calibration

This alert occurs when the economizer actuator reports a control
angle (Operating ModesECONC.ANG) less than the
minimum control angle (ConfigurationECONM.ANG).
Initiate economizer calibration (Service Test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.

S Economizer Damper Actuator Torque Above Load Limit

This alert occurs when the actuator load is too high. Investigate
to determinewhat is increasing damper load, and verify that the
actuator is the correct size for the unit. This alert resets
automatically.

S 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.

S 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.

S Economizer Damper Actuator Mechanical Failure

This alert occurs when the actuator sensesa catastrophic failure.
Investigateactuator and replace if necessary. This alert resets
automatically.

S 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.

S 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.

S 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.

30

S Economizer Not Economizing When It Should

In this case, the economizer should be enabled, but for some
reason it’s not providing free cooling.

S 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 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 Status
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.

Table 6 – ComfortLink Alarm Codes

ALARM

OR

ALERT

NUMBER

T051

T064

T066

T073 Outdoor Air Temper at ure Thermistor Failure No cooling with economizer Automatic

T074 Space Temperature Thermistor Fai lure

T075 Supply Air Temperature Thermistor Failure

T076 Return Air Thermi stor Fai lure

T077 Space Relative Humidity Sensor Failure

T092 Circuit A Suction Pressure Transducer Failure Lockout Circuit A Manual

T102 Compressor Current Sensor Failure No Circuit A Cooling Automatic

T110

T126

T133

T143

T153 Real Timecloc k Hardware Failure

A154 Serial EEPROM Hardw ar e Failure Unit Shutdown Automatic Soft w ar e failure or MBB failure

T155 Serial EEPROM Sto rage Failure Error Unit opera tion errors Automatic Softw are failure or MBB failure

A156 Critica l Seri al EEPROM Storage Fai l Erro r Unit Shutdown Automatic Softwar e failure or MBB failure

A157 A/D Hardware Failur e Un it Shutdown Automatic Softwar e failure or MBB failure

A163

T173

T175 Loss of communication with VFD Unit Shutdown Automatic

T179

T180

A200 Linkage Timeout Error - -- Comm Fail ure

A404 Fire Shutdown Unit Shutdown Automatic Sm oke detected by smoke detector

T408 Dirty Air Filter Aler t Generated Automatic Dirty Filter

T409

T410

Compresso r A1 Saf ety Trip
Service Test -- - Compressor A1 Sa fety Trip
Compress or A1 Detected After Turnoff
Service Test --- Compressor A1 Detected After

Tur no ff
Circuit A Saturate d Condensing Temp Thermistor

Failure
Circuit A Saturated Suction Temperature

Thermistor Failure

Circuit A Loss of Charge
Service Test -- - Circuit A Loss of Charge

Circuit A High Discha rge Pressure

Service Test -- - Circuit A High Discha rge P ressure

Circuit A Low Refrigerant Pressure

Service Test --- Ci rcuit A Low Ref rigerant
Pressure

Circuit A Fail ure To P ressurize
Service Test -- - Circuit A Fail ure to Pressurize

Circuit A Down Due to Failure
Service Test --- Circuit A Do wn Due to Fai lure

Loss o f communicatio n with the Energy
Management Module

Loss o f communicatio n with the Economizer
Control Board

Loss o f communicatio n with the Economizer
Actuator

Fan Status Switch ON, fan commanded off

Fan Status Switch OFF, fan commanded on

R-- -W1 J umper Not Installed in Space Temp
Mode

R-- -W1 Jumper M ust Be Insta lled to Run Hea t In
Service Test

DESCRIPTION

ACTION TAKEN BY

CONTROL

Add Strike fo r Circuit A Automatic

Turn off al l compressors Automatic Wel ded contactor

Limited Diagnostic Automatic

No Circuit A Cooling Automatic Circuit A Suction transducer interna lly forced inactive

If U.CTL = 3, then no

heating or coo ling

No cooling with economizer

and No adaptive

compresso r stag ing

If RAT .S = Yes, then no

differential Dry Bulb control

If RH.S = Yes, then no
indoor humidity control

Lockout Circuit A Manual Low refri gerant or faulty sucti on pre ssure tra nsducer

Shutdown Circuit A Automatic

Add Strike fo r Circuit A Automatic

Add Strike fo r Circuit A Automatic Wiring causing reverse rotation or faulty compressor

No time and date schedule

operation

Lockout Circuit A Manual C ir c uit has 3 strikes or has been locked out by another alarm

No action Automatic MBB Software failure, reload software or replace board

No economizer operation Automatic

No economizer operation Automatic Communication wiri ng problem with actuator.

No Linkage Operation fall

back to local SPT

If IDF.F = Yes, then Unit

Shutdown

If IDF.F = Yes, then Unit

Shutdown

Unable to run heat Automatic Missing jumper wire

Unable to Te s t Heat Outputs Automatic Missi ng jumper wi re

RESET

METHOD

High - -- pressure switch o pen. Compressor inte rnal protecti on
open. Wiring error

Faulty, shorted, or ope n thermistor cause d by wi ring error or
loose connection.

Faulty, shorted, or ope n thermistor cause d by wi ring error or
loose connection.

Automatic

Automatic

Automatic

Automatic

Automatic No time/date configured, software failure, or MBB failure

Automatic

If IDF.F = YES,

then Manual,

otherwise

automatic

If IDF.F = YES,

then Manual,

otherwise

automatic

Faulty, shorted, or ope n thermistor cause d by wi ring error or
loose connection.

Faulty, shorted, or ope n thermistor cause d by wi ring error or
loose connection.

Faulty, shorted, or ope n thermistor cause d by wi ring error or
loose connection.

Faulty,shorted,oropensensorcausedbywiringerroror
loose connection.

Faulty transdu c er, faulty 5--- V power supply, or loose
connection

Miswired, bad Current board, or no board ins talled but
configured fo r it.

An overcharged system, high outdoor ambient temper atu r e
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 t ransducer, e xcessively co ld re turn ai r , or stuck o pen
economizer when the ambient temperature is low.

Communication connection bad or miswired, misconfig u red
VFD.

Communicatio n wiring probl em with ECB o r faulty MBB or
ECB

Received a table write from Linkage before, now not
receiving any linkage command s

Bad Fan Status Switch. Configuration incorrect.

Tripped Circuit Breaker. Broken belt. Bad indoor fan motor.
Configuration incorrect. Bad fan status switch.

PROBABLE CAUSE



S.VFDLFC). Refer

48/50LC

31

Table 6 — ComfortLink Alarm Codes (cont)

ALARM

OR

ALERT

NUMBER

T411

T412

T413

T414

T415 IAQ Input Out of Range No IAQ Operati ons Automatic Bad sensor, bad wiring , or sens or configur ed incorrec t ly.

T416 OAQ Input Out of Range No OAQ Operati ons Automatic Bad sensor, bad wiring, or sensor configur ed incorrec t ly.

48/50LC

A420 Supply VFD Fault Unit Shutdown Automatic VFD f ault occurred, revi ew VFD fa ults.

LEGEND:
ECB ---Economizer Control Board IGC---Integrated Gas Controller MBB --- Main Base Board OAT --- O u td o o r --- A ir T h er m i st o r

Therm os t at Y2 Inpu t Activated without Y1
Activated

Therm os t at W2 Inpu t Activated without W1
Activated

Thermostat Y and W Inputs Activated
Simultan eou s ly

Economiz er Damper Actuator Out of Calibration Alert Generated Automati c

Economiz er Damper Actuator Torque Above
Load Limi t

Economiz er Damper Actuator Huntin g
Excessiv ely

Economizer Damper Stuck or Jamme d Alert Generated Automatic

Economiz er Damper Actuator Mechanical Failure Aler t Generated Automatic Check actuator and replace if necessary.
Economiz er Damper Actuator Direction Switch

Wrong
Excess Outdoor Air Alert Generated Automatic
Economizer Economizing When It Should Not Alert Generated Automatic
Economizer not Economizing When it Should Alert Generated Automatic
Damper Not Modulating Alert Generated Automati c

DESCRIPTION

ACTION TAKEN BY

CONTROL

Run unit as if Y2 and Y1 are

Rununitinmodeactivated

On

Run unit as if W2 and W1

are On

first

Alert Generated Automatic Actuator load too high. Check damper load.

Alert Generated Automatic Damper positio n changing too quickly.

Alert Generated Automatic Actuator direction control switch (CCW, CW) wrong.

RESET

METHOD

Automatic B ad The rmostat or Thermostat Wiring

Automatic B ad The rmostat or Thermostat Wiring

Automatic B ad The rmostat or Thermostat Wiring

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 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 LED’s 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 7, 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.

PROBABLE CAUSE

Calibrate economizer (E.CAL). If problem still exist then
determine what is limiting economiz e r rotation.

No economizer motion. Check damper blades, gears, and
actuator.

Device

MBB

ECB

Board Serial Num-

ber

Prior to 4702N

Starting 4702N

Prior to 0803N

Starting 0803N

Table 7 – LEN and CCN Communication Resistances

(LEN) Resis tance 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 
J2

18.9K 
J2

7.5K 

J3, J4, & J5

9.9K 

J3, J4, & J5

5.2K 
J2

9.9K 
J2

7.5K 

J3, J4, & J5

9.9K 

J3, J4, & J5

5K 

J2

9.9K 
J2

15K 

J5

18.9K 
J5

--- --- ---

--- --- ---

7.5K 
J5

9.9K 
J5

7.5K 
J5

9.9K 
J5

32

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 6.) Verify any unique control
configurations per installed site requirements or accessories.

Table 8 – Cooling Service Analysis

PROBLEM CAUSE REMEDY

Compressor and Fan Will Not
Start.

CompressorCycles(otherthan
normally satisfying thermostat).

Compressor Operates
Continuously.

Excessive Condenser Pressures.

Condenser Fans Not Operating. No Power to contactors. Fuse blown or plug at motor loose.

Excessive Suction Pressure.

Suction Pressure Too Low.

Compressor not running but
ComfortLINK Status show it is on.

LEGEND
CB --- Circuit Breaker
TXV --- T hermostatic Expansion Valve

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 Com fortLink 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

Insufficient line voltage. Determine cause and correct.

Active alarm. Check active alarms using ComfortLink Scrolling

Unit undersized for load. Decrease load or increase size of unit.

Thermostat or occupancy schedule set point t oo low. Resetthermostatorschedulesetpoint.

Dirty air filters. Replace filters.

Low refrigerant charge. Check pressure, locate leak, repair, evacuate, and

Condenser coil dirty or restricted. Clean coil or remove restriction.

Loose condenser thermistors. Tighten thermistors.

Dirty condenser coil. Clean coil.

Refrigerant overcharge. Recover excess refrigerant.

Faulty TXV. 1. Check TXV bulb mounting and secure tightly to

Condenser air restricted or air short cycling. Determine cause and correct.

Restrictioninliquidtube. Remove restriction.

High heat load. Check for sources and eliminate

Faulty TXV. 1. Check TXV bulb mounting and secure tightly to

Refrigerant overcharged. Recover excess refrigerant.

Dirty air filters. Replace air filters.

Low refrigerant charge. Check pressure, locate leak, repair, evacuate, and

Faulty TXV. 1. Check TXV bulb mounting and secure tightly to

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.

If alarms conditions are corrected and cleared, operation of the
compressors and fans may be verified by using the Service Test
mode. (See Table 4.) See Table 8 for general cooling service
analysis.

Check using Com fortLink Scrolling Marquee.

ComfortLink Scrolling Marquee.

Marquee.

Marquee.

recharge.

suction line an d insulate.

2. Replace TXV (and filter drier) if stuck open or
closed.

suction line an d insulate.

2. Replace TXV (and filter drier) if stuck open or
closed.

recharge.

suction line an d 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.

48/50LC

33

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 6.)
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 4). The
following steps specify how to test the economizer using the
Scrolling Marquee display. See Table 9 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

48/50LC

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
ECONE.CTL = 1or2). The economizer calibration
procedure (Service Test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.

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 whether

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 position 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

34

Table 9 – Economizer Service Analysis

PROBLEM POSSIBLE CAUSE REMEDY

Damper Does Not Move. Indoor Fan is off.

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.

Outdoor Damper Does Not Fully
Close at 0% or Fully Open at 100%.

Economizer is Not at Configured
Minimum Position

LEGEND
CCN --- Carrier Comfort Network
IAQ --- I n doo r A i r Q ual i t y

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. Econom izer is operating correctly, identify

IAQ is controlling minimum damper position. Adjust the IAQ settings if incorrect,

Unit is in Unoccupied mode. Adjust unit occupied schedule if incorrect,

Unit is operating under free cooling. Economizer is operating correctly.

Damper is jammed or spring return is backwards. Identify the obstruction and safely remove.

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 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.

Check wiring connections.

instructions.

Adjust the high temperature lockout setting
if it is incorrect, oth erwise, economizer is
operating correctly.

Adjust the low temperature lockout setting
if it is incorrect, oth erwise, economizer is
operating correctly.

Adjust the high temperature lockout setting
if it is incorrect, oth erwise, 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.

compressor problem.

otherwise, the economizer is operating correctly.

otherwise, economizer is operating correctly.

Enter Service Test mode and run the Calibrate
Economizer (E.CAL) procedure.

Economizer is operating correctly.

48/50LC

35

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 6.) Verify any unique control
configurations per installed site requirements or accessories. If
alarms conditions are corrected and cleared, operation of the heat
stages and indoor fan may be verified by using the Service Test
mode. (See Table 4.)

Table 10 – Gas Heating Service Analysis

PROBLEM CAUSE REMEDY

Heat Will Not Turn On.

Burners Will Not Ignite.

48/50LC

Inadequate Heating.

Poor Flame
Characteristics.

Burners Will Not Turn Off.

Unit is NOT configured for heat. Check heating configurations using the ComfortLink Scrolling

Active alarm. Check active alarms using ComfortLink Scrolling Marquee and

No power to unit. Check power supply, fuses, wiring, and circuit breakers.

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. After purging gas

Water in gas line. Drain water and install drip.

Dirty air filters. Replace air filters.

Gas input too low. Check gas pressure at manifold. Refer to gas valve adjustment.

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 SAT heating

Too much outdoor air. Check economizer position and configuration. Adjust minimum

Limitswitchcyclesmainburners. Check rotation of blower, thermostat heat anticipator settings,

Incomplete combustion (lack of combustion air)
results in: Aldehyde odors, CO, sooting flame, or
floating flame.

Unit is in Minimum on-t ime. Check using Com fortLink Scrolling Marquee and the IGC flash

Unit running in Service Test mode. Check using ComfortLink Scrolling Marquee.

Main gas valve stuck. Turn off gas supply and unit power. Replace gas valve.

Gas Heat (48LC Units)

See Table 10 for general gas heating service analysis. See Fig. 8 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 11.)

Electric Heat (50LC Units)

See Table 12 for electric heating service analysis.

Marquee

the IGC flash codes.

Check using Com fortLink Scrolling Marquee and the IGC flash
codes.

Check using Com fortLink Scrolling Marquee.

line of air, allow gas to dissipate for at least 5 minutes before
attempting to re-light unit.

Allow time for W2 to energize or adjust setpoints.

limits.

position using Com fortLink Scrolling Marquee.

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.

codes.

36

1 FLASH - INDOOR FAN DELAY

MODIFIED (HEATING)

2 FLASHES - OPENING OF LIMIT

5 FLASHES - IGNITION LOCKOUT

SWITCH

3 FLASHES - FLAME SENSOR

INDICATES FLAME WITH

CLOSED GAS VALVE

4 FLASHES - LIMIT SWITCH

CYCLED 4 TIMES ON SINGLE

CALL FOR HEAT

(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

FLASHING

LED is

ON

CALL FOR

COMBUSTION RELAY ENERGIZES INDUCED DRAFT MOTOR (IDM) THROUGH

IF IDM IS TURNING AT CORRECT SPEED (AT LEAST 2400 RPM), HALL

EFFECT SENSOR SENDS CORRECT SIGNAL TO TERMINAL ‘J1’ ON IGC

OFF

HEATING

‘W1’ FROM BASE CONTROL BOARD ENERGIZES ‘W’
ON IGC - 1 MINUTE LOCK-ON

COMBUSTION RELAY ON IGC IN ENERGIZED

TERMINAL ′CM′ ON IGC

24 VOLTS

BETWEEN

F1 AND C

1. BLOWN 5 AMP FUSE

2. DEFECTIVE 24V TRANS.

3. BROKEN WIRE

4. NO POWER TO UNIT

YES

No

DEFECTIVE
IGC BOARD

8 FLASHES - HARDWARE OR

SOFTWARE FAULT

9 FLASHES - SOFTWARE

LOCKOUT

No

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)

SWITCH ARE CLOSED, IGC SAFETY

IGC HIGH VOLTAGE

TRANSFORMER CREATES A

10,000 VOLT SPARK FOR 5

SECONDS

No

AFTER 45 SECONDS (OR LESS IF THE TIMING

HAS BEEN REDUCED DUE TO LIMIT SWITCH
TRIPS) IGC WILL ENERGIZE BLOWER RELAY

IF LIMIT SWITCH AND ROLLOUT

LOGIC WILL INITIATE IGNITION

SEQUENCE

IGC SAFETY LOGIC OPENS GAS

DOES IGC DETECT

.2 MICROAMPS FOR 2

SECONDS

Yes

SWITCH OPEN BEFORE THE 45

DID LIMIT

SECONDS (OR THE MODIFIED

TIME) HAS TIMED OUT?

VALVE FOR 5 SECONDS

Yes

SUBTRACT 5 SECONDS (OR

ANOTHER 5 SECONDS) FROM

INDOOR FAN ON TIME DELAY

48/50LC

LEGEND

IDM – Induced-Draft Motor
IGC – Integrated Gas Unit Controller

NOTE: Thermostat Fan Switch in the
“AUTO” position.

No

NORMAL HEATING OPERATION

HEATING DEMAND SATISFIED

IDM STOPS, SAFETY LOGIC SHUTS OFF GAS VALVE

(DELAY EXTENDED BY 5 SECONDS FOR EACH LIMIT SWITCH TRIP

45 SECOND BLOWER SHUTOFF DELAY

MAXIMUM DELAY: 3 MINUTES)

Fig. 8 -- IGC Service Analysis Logic

37

C07014

Table 11 – IGC Board LED Alarm Codes

LED

FLASH

DESCRIPTION

CODE

On Normal Operation
Off Hardware Failure No gas heating.

1Flash Indoor Fan On/Off Delay

Modified

2Flashes Limit Switch Fault Gas valve and igniter Off.

3Flashes Flame Sense Fault Indoor fan and inducer On. Flame sense normal.

4Flashes Four Consecutive Limit

Switch Fault

5Flashes Ignition Fault No gas heating. Heat call (W) Off.

48/50LC

6Flashes Induced Draft Motor

7Flashes Rollout Switch Lockout Gas valve and igniter Off.

8Flashes Internal Control Lockout No gas heating. Power reset. IGC has sensed internal hardware or software error. If

9Flashes Temporary Software

LEGEND
IGC --- Integrated Gas Unit Control
LED --- L i g h t --- E m i tti n g D iod e

Fault

Lockout

ACTION TAKEN BY

CONTROL

RESET METHOD PROBABLE CAUSE

— — —

—

5 seconds subtracted from
On delay.
5 seconds added to Off
delay (3 min max).

Indoor fan and inducer On.

No gas heating. Heat call (W) Off.

If heat off: no gas heating.
If heat on: gas valve Off
and inducer On.

Indoor fan and inducer On.

No gas heating. 1 hour auto reset, or

Power reset. High temperature limit switch opens during heat

Limit switch closed, or
heat call (W) Off.

Power reset for LED
reset.

Power reset for LED
reset.

Power reset for LED
reset.

Inducer sense normal, or
heat call (W) Off.

Power reset. Rollout switch has opened. Check gas valve

power reset.

NOTES:

1. Thereisa3---secondpausebetweenalarmcodedisplays.

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.

exchanger warm-up period before fan-on delay
expires.
High tem perature limit switch opens within
10 minutes of heat call (W) Off.
See Limit Switch Fault.

High tem perature 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.

TheIGCsensedaflamewhenthegasvalveshould
be closed. Check wiring, flame sensor, and gas valve
operation.

4 consecutive limi t switch faults within a single call for
heat. See Limit Switch Fault.

Unit unsucces s f ul ly attempted ignition for 15 minutes.
Check igniter and flame sensor electrode spacing, gaps,
etc. Check flame sense and igniter wir ing. 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.

operation. Check induced-draft blower wheel is
properly secured to motor shaft.

fault is n ot cleared by resetting 24 v power, replace
the IGC.

Electrical interference is disrupting the IGC software.

PROBLEM CAUSE REMEDY

Heat Will Not Turn On.

Inadequate Heating.

Heat Will Not Turn Off.

Table 12 – Electric Heat Service Analysis

Active alarm. Check active alarms using ComfortLink Scrolling Marquee.

Unit is NOT configured for heat. Check heating configurations using the ComfortLink

No power to unit. Check power supply, fuses, wiring, and circuit breakers.
Unit is in minimum heat off-time, or min imum cool-h eat

changeover time.

Thermostat or occupancy schedule setpoint not
calling for heating.

Heat forced off in Service Test mode. Check using ComfortLink Scrolling Marquee. Turn Service

No 24 vac at heater contactor.

Open temperature limit switch on heater. Check minimum airflow. Check limit switch when it is cool,

Dirty air filters. Replace air filters.
Thermostat or occupancy schedule setpoint only

calling for W1.

Heat un dersized for load. Decrease load or increase size of heater.
Restricted airflow Remove restriction. Check SAT compared to the SAT

Too much outdoor air. Check economizer position and configuration. Adjust

Limit switch cycles heaters. Check rotation of blower and minimum airflow.
Bad heater elements. Power off unit and remove high voltage wires. Check

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. Check using ComfortLink Scrolling Marquee. Turn Service

Heater contactor failed. Power off unit. Check contactor and replace if closed.

Scrolling Marquee

Check using ComfortLink Scrolling Marquee.

Check using ComfortLink Scrolling Marquee.

Tes t m od e o ff .

Check transformer and circuit breaker.
Check auto-reset limit switches on heater.
Check manual-reset limit switch (LS) on indoor fan housing.

replace if open.

Allow time for W2 to energize or adjust setpoints.

heating limits.

minimum position.

resistance of element, replace if open.

Check using ComfortLink Scrolling Marquee.

Tes t m od e o ff .

38

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 24-vac 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 table below.

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 Table 13 and 14. 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. 9.) To reinstall, make sure the snap-mount tabs extend out.

Refrigerant Temperature

Condenser coil temperature is measured with 5 kilo-ohm
thermistors. The measurement provides an approximate saturated
condensing temperature. Fig. 10 shows 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.

C07015

Fig. 9 -- SAT and OAT Thermistor Mounting

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 section).

Using the voltage reading obtained, read the sensor temperature
from Table 13 and 14.

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TRIM menu for the display, or 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,oran
offset temperature value in SAT.T. If installed, 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.

48/50LC

39

SCT.A

48/50LC

SCT.A

Size 04 Units

Fig. 10 -- Saturated Condensing Temperature Thermistor Location — 48/50LC04--06

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 15, 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 15. 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

Size 05 & 06 Units

C12219

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.

40

Table 13 – Temperature (_F) vs Resistance/VoltageDrop Values for OAT, SAT, and SPT Thermistors (10K at 25_C Type II Resistors)

TEMP

(F)
–25 196,453 4.758
–24 189,692 4.750
–23 183,300 4.741 61 2.994 14,925
–22 177,000 4.733 62 2.963 14,549
–21 171,079 4.724 63 2.932 14,180 147 0.890 2,166
–20 165,238 4.715 64 2.901 13,824 148 0.876 2,124
–19 159,717 4.705 65 2.870 13,478 149 0.862 2,083
–18 154,344 4.696 66 2.839 13,139 150 0.848 2,043
–17 149,194 4.686 67 2.808 12,814 151 0.835 2,003
–16 144,250 4.676 68 2.777 12,493 152 0.821 1,966
–15 139,443 4.665 69 2.746 12,187 153 0.808 1,928
–14 134,891 4.655 70 2.715 11,884 154 0.795 1,891
–13 130,402 4.644 71 2.684 11,593 155 0.782 1,855
–12 126,183 4.633 72 2.653 11,308 156 0.770 1,820
–11 122,018 4.621 73 2.622 11,031 157 0.758 1,786
–10 118,076 4.609 74 2.592 10,764 158 0.745 1,752

–9 114,236 4.597 75 2.561 10,501 159 0.733 1,719
–8 110,549 4.585 76 2.530 10,249 160 0.722 1,687
–7 107,006 4.572 77 2.500 10,000 161 0.710 1,656
–6 103,558 4.560 78 2.470 9,762 162 0.699 1,625
–5 100,287 4.546 79 2.439 9,526 163 0.687 1,594
–4 97,060 4.533 80 2.409 9,300 164 0.676 1,565
–3 94,020 4.519 81 2.379 9,078 165 0.666 1,536
–2 91,019 4.505 82 2.349 8,862 166 0.655 1,508
–1 88,171 4.490 83 2.319 8,653 167 0.645 1,480

0 85,396 4.476 84 2.290 8,448 168 0.634 1,453
1 82,729 4.461 85 2.260 8,251 169 0.624 1,426
2 80,162 4.445 86 2.231 8,056 170 0.614 1,400
3 77,662 4.429 87 2.202 7,869 171 0.604 1,375
4 75,286 4.413 88 2.173 7,685 172 0.595 1,350
5 72,940 4.397 89 2.144 7,507 173 0.585 1,326
6 70,727 4.380 90 2.115 7,333 174 0.576 1,302
7 68,542 4.363 91 2.087 7,165 175 0.567 1,278
8 66,465 4.346 92 2.059 6,999 176 0.558 1,255

9 64,439 4.328 93 2.030 6,838 177 0.549 1,233
10 62,491 4.310 94 2.003 6,683 178 0.540 1,211
11 60,612 4.292 95 1.975 6,530 179 0.532 1,190
12 58,781 4.273 96 1.948 6,383 180 0.523 1,169
13 57,039 4.254 97 1.921 6,238 181 0.515 1,148
14 55,319 4.235 98 1.894 6,098 182 0.507 1,128
15 53,693 4.215 99 1.867 5,961 183 0.499 1,108
16 52,086 4.195 100 1.841 5,827 184 0.491 1,089
17 50,557 4.174 101 1.815 5,698 185 0.483 1,070
18 49,065 4.153 102 1.789 5,571 186 0.476 1,052
19 47,627 4.132 103 1.763 5,449 187 0.468 1,033
20 46,240 4.111 104 1.738 5,327 188 0.461 1,016
21 44,888 4.089 105 1.713 5,210 189 0.454 998
22 43,598 4.067 106 1.688 5,095 190 0.447 981
23 42,324 4.044 107 1.663 4,984 191 0.440 964
24 41,118 4.021 108 1.639 4,876 192 0.433 947
25 39,926 3.998 109 1.615 4,769 193 0.426 931
26 38,790 3.975 110 1.591 4,666 194 0.419 915
27 37,681 3.951 111 1.567 4,564 195 0.413 900
28 36,610 3.927 112 1.544 4,467 196 0.407 885
29 35,577 3.903 113 1.521 4,370 197 0.400 870
30 34,569 3.878 114 1.498 4,277 198 0.394 855
31 33,606 3.853 115 1.475 4.185 199 0.388 841
32 32,654 3.828 116 1.453 4,096 200 0.382 827
33 31,752 3.802 117 1.431 4,008 201 0.376 814
34 30,860 3.776 118 1.409 3,923 202 0.370 800
35 30,009 3.750 119 1.387 3,840 203 0.365 787
36 29,177 3.723 120 1.366 3,759 204 0.359 774
37 28,373 3.697 121 1.345 3,681 205 0.354 762
38 27,597 3.670 122 1.324 3,603 206 0.349 749
39 26,838 3.654 123 1.304 3,529 207 0.343 737
40 26,113 3.615 124 1.284 3,455 208 0.338 725
41 25,396 3.587 125 1.264 3,383 209 0.333 714
42 24,715 3.559 126 1.244 3,313 210 0.328 702
43 24,042 3.531 127 1.225 3,244 211 0.323 691
44 23,399 3.503 128 1.206 3,178 212 0.318 680
45 22,770 3.474 129 1.187 3,112 213 0.314 670
46 22,161 3.445 130 1.168 3,049 214 0.309 659
47 21,573 3.416 131 1.150 2,986 215 0.305 649
48 20,998 3.387 132 1.132 2,926 216 0.300 639
49 20,447 3.357 133 1.114 2,866 217 0.296 629
50 19,903 3.328 134 1.096 2,809 218 0.292 620
51 19,386 3.298 135 1.079 2,752 219 0.288 610
52 18,874 3.268 136 1.062 2,697 220 0.284 601
53 18,384 3.238 137 1.045 2,643 221 0.279 592

54 17,904 3.208
55 17,441 3.178
56 16,991 3.147 140 0.996 2,488
57 16,552 3.117 141 0.980 2,439
58 16,131 3.086 142 0.965 2,391

RESISTANCE

(Ohms)

VOLTAGE
DROP (V)

TEMP

(F)

RESISTANCE

(Ohms)

VOLTAGE
DROP (V)

TEMP

(F)

VOLTAGE
DROP (V)

RESISTANCE

(Ohms)

59 3.056 15,714 143 0.949 2,343
60 3.025 15,317 144 0.934 2,297

145 0.919 2,253
146 0.905 2,209

138 1.028 2,590 222 0.275 583
139 1.012 2,539 223 0.272 574

224 0.268 566
225 0.264 557

48/50LC

41

Table 14 – 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 0.511 1,190
–24 3.689 94,707 60 1.956 7,665 144 0.502 1,165
–23 3.679 91,522 61 1.930 7,468 145 0.494 1,141
–22 3.668 88,449 62 1.905 7,277 146 0.485 1,118
–21 3.658 85,486 63 1.879 7,091 147 0.477 1,095
–20 3.647 82,627 64 1.854 6,911 148 0.469 1,072
–19 3.636 79,871 65 1.829 6,735 149 0.461 1,050
–18 3.624 77,212 66 1.804 6,564 150 0.453 1,029
–17 3.613 74,648 67 1.779 6,399 151 0.445 1,007
–16 3.601 72,175 68 1.754 6,238 152 0.438 986
–15 3.588 69,790 69 1.729 6,081 153 0.430 965
–14 3.576 67,490 70 1.705 5,929 154 0.423 945
–13 3.563 65,272 71 1.681 5,781 155 0.416 925
–12 3.550 63,133 72 1.656 5,637 156 0.408 906
–11 3.536 61,070 73 1.632 5,497 157 0.402 887
–10 3.523 59,081 74 1.609 5,361 158 0.395 868

–9 3.509 57,162 75 1.585 5,229 159 0.388 850
–8 3.494 55,311 76 1.562 5,101 160 0.381 832
–7 3.480 53,526 77 1.538 4,976 161 0.375 815
–6 3.465 51,804 78 1.516 4,855 162 0.369 798
–5 3.450 50,143 79 1.493 4,737 163 0.362 782
–4 3.434 48,541 80 1.470 4,622 164 0.356 765
–3 3.418 46,996 81 1.448 4,511 165 0.350 750
–2 3.402 45,505 82 1.426 4,403 166 0.344 734
–1 3.386 44,066 83 1.404 4,298 167 0.339 719

48/50LC

0 3.369 42,679 84 1.382 4,196 168 0.333 705

1 3.352 41,339 85 1.361 4,096 169 0.327 690

2 3.335 40,047 86 1.340 4,000 170 0.322 677

3 3.317 38,800 87 1.319 3,906 171 0.317 663

4 3.299 37,596 88 1.298 3,814 172 0.311 650

5 3.281 36,435 89 1.278 3,726 173 0.306 638

6 3.262 35,313 90 1.257 3,640 174 0.301 626

7 3.243 34,231 91 1.237 3,556 175 0.296 614

8 3.224 33,185 92 1.217 3,474 176 0.291 602

9 3.205 32,176 93 1.198 3,395 177 0.286 591

10 3.185 31,202 94 1.179 3,318 178 0.282 581
11 3.165 30,260 95 1.160 3,243 179 0.277 570
12 3.145 29,351 96 1.141 3,170 180 0.272 561
13 3.124 28,473 97 1.122 3,099 181 0.268 551
14 3.103 27,624 98 1.104 3,031 182 0.264 542
15 3.082 26,804 99 1.086 2,964 183 0.259 533
16 3.060 26,011 100 1.068 2,898 184 0.255 524
17 3.038 25,245 101 1.051 2,835 185 0.251 516
18 3.016 24,505 102 1.033 2,773 186 0.247 508
19 2.994 23,789 103 1.016 2,713 187 0.243 501
20 2.972 23,096 104 0.999 2,655 188 0.239 494
21 2.949 22,427 105 0.983 2,597 189 0.235 487
22 2.926 21,779 106 0.966 2,542 190 0.231 480
23 2.903 21,153 107 0.950 2,488 191 0.228 473
24 2.879 20,547 108 0.934 2,436 192 0.224 467
25 2.856 19,960 109 0.918 2,385 193 0.220 461
26 2.832 19,393 110 0.903 2,335 194 0.217 456
27 2.808 18,843 111 0.888 2,286 195 0.213 450
28 2.784 18,311 112 0.873 2,239 196 0.210 445
29 2.759 17,796 113 0.858 2,192 197 0.206 439
30 2.735 17,297 114 0.843 2,147 198 0.203 434
31 2.710 16,814 115 0.829 2,103 199 0.200 429
32 2.685 16,346 116 0.815 2,060 200 0.197 424
33 2.660 15,892 117 0.801 2,018 201 0.194 419
34 2.634 15,453 118 0.787 1,977 202 0.191 415
35 2.609 15,027 119 0.774 1,937 203 0.188 410
36 2.583 14,614 120 0.761 1,898 204 0.185 405
37 2.558 14,214 121 0.748 1,860 205 0.182 401
38 2.532 13,826 122 0.735 1,822 206 0.179 396
39 2.506 13,449 123 0.723 1,786 207 0.176 391
40 2.480 13,084 124 0.710 1,750 208 0.173 386
41 2.454 12,730 125 0.698 1,715 209 0.171 382
42 2.428 12,387 126 0.686 1,680 210 0.168 377
43 2.402 12,053 127 0.674 1,647 211 0.165 372
44 2.376 11,730 128 0.663 1,614 212 0.163 367
45 2.349 11,416 129 0.651 1,582 213 0.160 361
46 2.323 11,112 130 0.640 1,550 214 0.158 356
47 2.296 10,816 131 0.629 1,519 215 0.155 350
48 2.270 10,529 132 0.618 1,489 216 0.153 344
49 2.244 10,250 133 0.608 1,459 217 0.151 338
50 2.217 9,979 134 0.597 1,430 218 0.148 332
51 2.191 9,717 135 0.587 1,401 219 0.146 325
52 2.165 9,461 136 0.577 1,373 220 0.144 318
53 2.138 9,213 137 0.567 1,345 221 0.142 311
54 2.112 8,973 138 0.557 1,318 222 0.140 304
55 2.086 8,739 139 0.548 1,291 223 0.138 297
56 2.060 8,511 140 0.538 1,265 224 0.135 289
57 2.034 8,291 141 0.529 1,240 225 0.133 282
58 2.008 8,076 142 0.520 1,214

RESISTANCE

(Ohms)

VOLTAGE
DROP (V)

TEMP

(F)

RESISTANCE

(Ohms)

VOLTAGE
DROP (V)

TEMP

(F)

VOLTAGE
DROP (V)

RESISTANCE

(Ohms)

42

Table 15 – Pressure (psig) vs. Voltage Drop Values for Suction Pressure Transducers

PRESSURE

(psig)

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 2.710

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 1.627 186 2.297 254 2.966

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

(psig)

VOLTAGE
DROP (V)

PRESSURE

(psig)

VOLTAGE

DROP (V)

PRESSURE

(psig)

VOLTAGE
DROP (V)

48/50LC

MAJOR SYSTEM COMPONENTS

General

The 48/50LC 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. 11
through 15 for the control and power schematics for 48/50LC.

43

48/50LC

Fig. 11 -- 48LC 04--06 ComfortLink Control Schematic

44

C12220

48/50LC

Fig. 12 -- 50LC 04--06 ComfortLink Control Schematic

45

C12221

48/50LC

Fig. 13 -- 48LC 04--06 ComfortLink Power Schematic -- 208/230V, 460V 3 Phase Units

46

C12222

48/50LC

Fig. 14 -- 48LC 04--06 ComfortLink Power Schematic --575V 3 Phase Units

47

C12223

48/50LC

Fig. 15 -- 50LC 04--06 ComfortLink Power Schematic -- 208/230V, 460V, 575V 3 Phase Units

48

C12224

Main Base Board (MBB)

See Fig. 16 and Table 16. 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.

RED LED - STATUS GREEN LED -

LEN (LOCAL EQUIPMENT NETWORK)

CEPL130346-01

J1

J6

J4

J5

J2

J3

LEN

CCN

STATUS

YELLOW LED ­CCN (CARRIER COMFORT NETWORK)

INSTANCE JUMPER (SET TO 1)

48/50LC

J10

J7

J8

Fig. 16 -- Main Base Board (MBB)

J9

C07026

49

Table 16 – Main Base Board (MBB) Connections

DISPLAY

NAME

Input power from TRAN2 control box 24 VAC J 1 , 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) spa ce switch input J7, 8

Y1 Thermostat Y1 (1st Stage Cool) space switch input J7, 10

FIL.S Filter stat us switch indoor fan section switch input J 9 , 2 --- 3

HUM Humidist at switch input spa ce switch input J 9 , 5 --- 6

Not Used 0--- 5vdc digital input J 9 , 7 --- 9

Not Used 0--- 5vdc digital input J 9 , 1 0 --- 1 2

SPT Space temperature (T55/56) space 10k thermistor J 8 , 1 --- 2

SPTO Space temperature offset (T56) space 10k thermistor J 8 , 2 --- 3

OAT Outdoor air temperature outdoor coil support 10k thermistor J 8 , 5 --- 6

SAT Supply air temperature

48/50LC

SCT.A Saturated condenser temperature, circuit A outdoor coil, circuit A 5k thermistor J 8 , 9 --- 1 0

Not Used 5k thermistor J 8 , 1 1 --- 1 2

RAT Return Air Temperature Return 10k thermistor J 8 , 1 3 --- 1 4

FAN.S Fan status switch indoor fan section switch input J 8, 1 5 --- 1 6

SSP.A Suction pressure, circuit A compressor A suct ion pipe

Not Used

Not Used 0 --- 5 V D C J 8 , 2 4 --- 2 6

L.ODF Low Ambient Outdoor Fan relay J10, 3

Not Used relay J10, 6

Not Used relay J10, 9

IDF.1 Indoor Fan Speed relay 1 relay J10, 11

IDF.2 Indoor Fan Speed relay 2 relay J10, 13

IDF.3 Indoor Fan Speed relay 3 relay J10, 16

ALRM Alarm relay relay J10, 19

COMP.A Circuit A Compressor relay J10, 21

LDR.A Circuit A Loader relay J10, 23

HT.1 Heat Stage 2 relay relay J10, 25

HT.2 Heat Stage 1 relay relay J10, 27

Local Equipment Network (LEN) communication J 5 , 1 --- 3

Carrier Comfort Network (CCN) communication J 5 , 5 --- 7

Network device power 24 VAC J 5 , 9 --- 1 0

Scrolling Marquee Display (LEN) communication J 4 , 1 --- 3

Scrolling Marquee Display power 24 VAC J 4 , 5 --- 6

Expansion LEN Bus communication J 3 , 1 --- 3

Optional ECB power 24 VAC J 2 , 1 --- 2

POINT DESCRIPTION SENSOR LOCATION TYPE OF I/O

INPUTS

indoor fan housing, or

supply duct

OUTPUTS

COMMUNICATION

10k thermistor J8, 7 --- 8

0 --- 5 V D C p r e s s ur e

transducer

0 --- 5 V D C p r e s s ur e

transducer

CONNECTION

PIN NUMBER

J 8 , 1 8 --- 2 0

J 8 , 2 1 --- 2 3

50

Economizer Control Board (ECB)

The ECB controls the economizer actuator. (See Fig. 17 and Table

17.) 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ECONE.CTL. The ECB has inputs for
Indoor Air Quality (IAQ), Outdoor Air Quality (OAQ), enthalpy
and RH sensor. It also controls two power exhaust outputs.

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
information 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.

48/50LC

Fig. 17 -- Economizer Control Board (ECB)

51

C07027

Table 17 – Economizer Control Board (ECB) Connections

DISPLAY NAME POINT DESCRIPTION

Input power from MBB control box 24 VAC J 1 , 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 --- 2 0 m A J5, 2

OAQ or
SP.RH

PE.1 Power exhaust 1 relay relay J8, 3

PE.2 Power exhaust 2 relay relay J8, 6

EC.CP Commanded Economizer position 0 --- 2 0 m A J9, 1

48/50LC

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

COMMUNICATION

Local Equipment Network (LEN) communication J2 , 1 --- 3

Carrier Comfort Network (CCN) communication J3

Economizer actuator position
(digital control)

SENSOR

LOCATION

INPUTS

economizer, or

return/space

field installed 0 --- 2 0 m A J5, 5

OUTPUTS

TYPE OF I/O

switch input J4, 4

MFT communicat ion J7, 1

CONNECTION

PIN NUMBER

52

Integrated Gas Control (IGC) Board

The IGC is provided on gas heat units. (See Fig. 18 and Table 18.)
The IGC controls the direct spark ignition system and monitors the
rollout switch, limit switch, and induced-draft motor Hall Effect
switch.

RED LED-STATUS

48/50LC

Fig. 18 -- Integrated Gas Control (IGC) Board

Table 18 – Integrated Gas Control (IGC) Board Connections

TERMINAL

LABEL

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 J 2 , 5 --- 6

LS Limit switch gas section switch input J 2 , 7 --- 8

CS Centrifugal switch (not used) switch input J 2 , 9 --- 1 0

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 o n IGC

POINT DESCRIPTION SENSOR LOCATION TYPE OF I/O

INPUTS

OUTPUTS

CONNECTION

PIN NUMBER

C07028

53

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 the back has
spade connectors. This board provides connection fo the thermostat,
space sensor, and most field installed accessories. See Table 19.

Table 19 – Field Connection Terminal Board (TB) Connections (04--14 Size Units)

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) spa ce 10k thermistor 14

S P T --- 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 (norma lly open) space 24 VAC output 3

G G Thermostat G (Fan) space 24 VAC input 4

W1 W1 The rmostat W1 (1st stage heat) space 24 VAC input 5

W2 W2 The rmostat W2 (2nd st age heat) space 2 4 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 section 10k thermistor 15,16

48/50LC

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 --- 2 0 m A i n p u t 23

SPRH SP.RH or OAQ

RMOC RM.OC Remote occupancy switch field installed 24 VAC input 25

ENTH

*Point name displayed on the Scrolling Marquee or Navigator.

DISPLAY

NAME*

ENTH or
IAQ.S

DESCRIPTION

Relative humidity sensor or
Outdoor air quality sensor

Outdoor enthalpy switch, or
Indoor air quality switch

Not Used 11,19,20,28,29

SENSOR

LOCATION

field installed 4 --- 2 0 m A i n p ut 21

economizer, or

return/space

TYPE OF I/O

24 VAC input 26

TERMINAL NUM-

BER

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 handheld Navigator to be plugged in to access
the unit’s menus. The Carrier Comfort Network

R

(CCN) RJ--11
connector or the CCN screw terminals allow building
communication connections. See Fig. 19.

(+) (-)(com) shield

1

LEN CCN

2

CCN

4

3

C11508

Fig. 19 -- 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. 20 and
Table 20 for the connections through this board.

54

Fig. 20 -- Central Terminal Board (CTB)

C11509

Table 20 – Central Terminal Board (CTB) Connections

CONNECTION LA-

BEL

DDC

T’STAT

ECON

CLO1/

COMP1

CLO2/

COMP2

CIRCUIT 1

CIRCUIT 2

CONTRL

BOARD

PMR

UNIT

SHUTDOWN

R Spades Transformer1PowerafterSafetyChain(T1J9) CONTL BOARD

C Spades Ground CONTL BOARD

The References above for T1J1 through T1J9 are to show the path of t ransformer 1 as is goes through the board and safety devices.

PIN NUMBER POINT DESCRIPTION 24Vac FROM 24Vac TO

7 Cool 1 Call MBB ECON

6 Cool 2 Call MBB ECON

5 Heat Stage 1 Call MBB CONTL BOARD

4 Heat Stage 2 Call MBB CONTL BOARD

3 IGC Fan Input MBB CONTL BOARD

1,2 Cool 1 Call jumper DDC T’STAT CLO1/COMP1

3,4 Cool 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

2 Loader Common CTB C Comp. Loader

3 OFMC Common CTB C O F MC --- B R N

4,5 Loader jumper ECON CIRCUIT 2 LPS

6 Loader Contactor Signal CIRCUIT 2 HPS Comp. Loader

7 ODF H igh Speed Signal ECON O F M C --- Y E L

HPS Comp 1 High Pressure Switch CIRCUIT 1 LPS CLO1/COMP1

LPS Comp 1 jumper CLO1/COMP1 CIRCUIT 1 H PS

HPS Loader jumper CIRCUIT 2 LPS CLO2/COMP2

LPS Loader 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 I G C --- W o r P L 3

4 IGC Common/Ground CTB C IGC C

5 Transformer 1 Common/Ground TRAN1 Common CTB C

6 IGC Call for Indoor fan IGC IFO CONTL BOARD

7 IGC Call for Indoor fan/Fan feedback CONTL BOARD MBB

8 IGC power (T1J9) CTB R IGC R

9 Transformer1Power(T1J1) TRAN1 24Vac UNIT SHUTDOWN

10 Limit Switch signal (T1J9) LSM CTB R

11 Limit Switch source (T1J8) PMR Fan overload

1 Ground CTB C PMR Device

2 Phase Monitor Source (T1J6) UNIT SHUTDOWN PMR Device

3 Phase Monitor Normally Closed Signal (T1J7) PMR Device CONTL BOARD

REMOTE

SHUTDOWN

SMOKE

SHUTDOWN

24V OUT Smoke Detector Controller Power (T1J2) CONTL BOARD Smoke Detector

C Smoke Detector Controller Common CTB C Smoke Detector

Remote Disable Switch if installed (T1J4 and T1J5) SMOKE SHUTDOWN PMR

Normally Closed Smoke Detector Contact (T1J3) Smoke Detector REMOTE SHUTDOWN

48/50LC

55

Variable Frequency Drive (VFD)

On units equipped with supply fan VFDs, the indoor fan motor is
controlled by a 3-phase VFD. The supply fan VFD is located in the
supply fan section behind the access door. These units use ABB
VFDs. The VFD varies the frequency of the AC voltage supplied
to the indoor fan. This allows the variance in the speed of the fan.
The VFD is always powered during normal operation and the fan
is stopped by driving the speed to 0. Fig. 21 and Table 21 show the
VFD terminals and connections.

48/50LC

TERMINALS

10 – 16

POWER

LED

FAULT

LED

Table 21 – VFD Connections

POINT DESCRIPTION TYPE OF I/O

Low Voltage Power
(jumped to DI1 & DI4)

Low Voltage Common
(jumped to DCOM)

Discrete Inputs Common
(jumped from GND)

Discrete Input 1
(jumped from 24v)

Not Used Switch Input 14 DI2

Not Used Switch Input 15 DI3

Discrete Input 4
(jumped from 24v)

Shielded Cable Ground Shield 28 SCR

LEN communication LEN 29 B+

LEN communication LEN 30 A ---

LEN Communication LEN 31 AGND

Vol t a g e L e g f r o m C --- 1 1 Voltage Input U1 MAINS

Vol t a g e L e g f r o m C --- 1 3 Voltage Input V1 MAINS

Voltag e L eg fro m IF TB Voltage Input W1 MAINS

Vol t a g e L e g t o I F M --- 3 Vol tag e Out put U2 MOTOR

Vol t a g e L e g t o I F M --- 2 Vol tag e Out put V2 MOTOR

Vol t a g e L e g t o I F M --- 1 Vol tag e Out put W2 MOTOR

LOW VOLTAGE INPUTS

24vdc 10 24v

Ground 11 GND

Ground 12 DCOM

Switch Input 13 DI1

Switch Input 16 DI4

HIGH VOLTAGE

!

CAUTION

TERMINAL

NUMBER

TERMINAL

NAME

TERMINALS

28 – 31

U1 V1 W1 U2 V2 W2

C12225

Fig. 21 -- Variable Frequency Drive (VFD) Terminals and

Connections -- unit shown front cover removed

The VFD is factory–configured to match the current and power
requirements for each motor selection and all wiring connections
are completed by the factory; no field adjustments or connections
are necessary. While the basic VFD retains all of its standard
capabilities, this application uses only a limited portion of these
features to provide discrete output speeds to the motor.
Consequently the VFD is not equipped with a keypad. A keypad is
available as an accessory (PNO CRDISKIT001A00) for
field—installation or expanded service access to VFD parameter
and troubleshooting tables. The VFD used has soft start capabilities
to slowly ramp up the speeds, eliminating any high inrush of air
volume during speed changes.

EQUIPMENT DAMAGE/PERFORMANCE HAZARD

Failure to follow this caution may result in damage to the unit
or in degradation of unit performance.

Do not run the Carrier Assistant through the VFD keypad.
This will cause parameters to change value that are not desired
on these applications.

The VFDs communicate to the ComfortLink MBB over the local
equipment network (LEN). The VFD speed is controlled directly
by the ComfortLink controls over the LEN. The VFD parameters
required to allow the VFD to communicate on the LEN are shown
in Table 22. These are factory set and would only need to be
adjusted if replacing the drive. Table 23 shows VFD parameters
that are set by the ComfortLink controls, and sent to the VFD over
the LEN at power up of the VFD. These are hard-coded to be set as
listed. The parameters listed in Table 24 have corresponding
ComfortLink configurations (Configuration I.FAN  S.VFD).
The factory sets these parameters per motor installed in the unit and
these should not be adjusted in the field. These are only provided
for drive or motor replacement or future adjustments. These
parameters in Table 24 require the drive to be off or 0% to change
them. Table 25 lists the status information the VFD sends to the

ComfortLink controls. This table is updated at every scan the
ComfortLink controls perform of the LEN. This occurs

approximately once every second.

!

WARNING

EQUIPMENT DAMAGE HAZARD

Failure to follow this warning could result in equipment
damage.

The VFD motor parameters shown in Table 26 should never be
changed in the field unless authorized by Carrier Corporation.
Damage could occur to the motor or unit if these are set to
anything besides what is shown in the table. These are only
provided for drive or motor replacement or future adjustments.

56

Table 22 – VFD Parameters Configured by Factory or VFD Keypad

Parameter Group Parameter Tit le ABB Parameter HVAC Default CARRIER

Options COMM PROT SEL 9802 NOT SEL LEN (6)

EFB PROTOCOL ID 5301 0000 hex 0601 hex

EFB STATION ID 5302 0 41

EFB Protocol

EFB BAUD RATE 5303 9.6 kb/s 38.4 kb/s

EFB PARITY 5304 8NONE1 8NONE1

EFB CTRL PROFILE 5305 ABB DRV LIM DCU PROFILE

Table 23 – VFD Parameters Hard Coded by ComfortLink

Parameter Group Parameter Tit le ABB Parameter HVAC Default CARRIER

Start/Stop/Dir EXT1 COMMANDS 1001 DI1 COMM (2)

Reference Select REF1 SELECT 1103 AI1 COMM (2)

Constant Speeds CONST SPEED 7 1208 60 Hz 0Hz

RUN ENABLE 1601 NOT SEL NOT SEL (0)

System Controls

Start/Stop

Fault Functions

FAULT RESET SEL 1604 KEYPAD COMM (7)

START ENABLE 1 1608 DI4 DI4 (4)

START FUNCTION 2101 SCALAR FLYSTART AUTO (0)

STOP FUNCTION 2102 COAST COAST (1)

COMM FAULT FUNC 3018 NOT SEL CONST SP 7 (2)

COMM FAULT TIME 3019 10.0 s 10.0 s

Table 24 – VFD Parameters Configurable Through ComfortLink

Param eter

Group

S t a rt --- U p D a t a

Start/Stop/Dir DIRECTION 1003 FORWARD REQUEST VFD1MDIR M.DIR

Limits MAXIMUM CURRENT 2003 1.3*I2n See Table 26 VFD1MAXA MAX.A

Accel/Decel

Motor Control SWITCHING FREQ 2606 4kHz 4kHz VFD1SWF Q SW.FQ

* The VFD must be running 0% speed to be able to change these through ComfortLink.

Param eter Title ABB Parameter HVAC Default CARRIER CCN POINT*

MOTOR NOM VOLT 9905 230V,460V,575V See Table 26 VFD1NVLT N.VLT

MOTOR NOM CURR 9906 1.0*In See Table 26 VFD1NAMP N.AMP

MOTOR NOM FREQ 9907 60 Hz 60 Hz VFD1 NFRQ N.FRQ

MOTOR NOM SPEED 9908 1750 rpm See Table 26 VFD1NRPM N.RPM

MOTOR NOM POWER 9909 1.0*Pn Se e Table 26 VFD1NPWR N.PWR

ACCELER TIME 1 2202 30.0s 30.0s VFD1ACCL ACCL

DECELER TIME 1 2203 30.0s 10.0s VFD1DECL DECL

Display Menu

48/50LC

Item*

Table 25 – VFD Standard Parameters Through ComfortLink

Parameter Group Parameter T itle ABB Parameter Units CCN POINT Display Menu Item

FB STS WORD 1 VFD1STAT

SPEED (%) % VFD1_SPD SPD

SPEED 0102 rpm VFD1RPM RPM

OUTPUT FREQ 0103 Hz VFD1FREQ FREQ

CURRENT 0104 A VFD1AMPS AMPS

TORQUE 0105 % VFD1TORQ TORQ

POWER 0106 kW VFD1PWR PWR

DC BUS VOLTAGE 0107 V VF D1VDC VDC

OUTPUT VOLTAGE 0109 V VF D1VOUT V. OU T

Operating Data

Fault History LAST FAULT 401 VFD1LFC LFC

DRIVE TEMP 0110 °C VFD1TEMP TEMP

RUN TIME (R) 0114 h VFD1RUNT RUN.T

KWH COUNTER (R) 0115 kWh VFD1KWH KWH

DI1 STATUS 0118 VFD1 _DI1

DI2 STATUS 0118 VFD1 _DI2

DI3 STATUS 0118 VFD1 _DI3

DI4 STATUS 0119 VFD1 _DI4

DI5 STATUS 0119 VFD1 _DI5

DI6 STATUS 0119 VFD1 _DI6

AI1 0120 VFD1_AI1

AI2 0121 VFD1_AI2

57

Table 26 – VFD Motor Default Configurations

UNIT

SIZE

(Digits

7&8)

03

04

05

*If Digit 10 is a 0 or 1 there is no VFD so th ese parameters will default to Medium (2) option

48/50LC

For proper operation, there are three jumper wires that must remain

UNIT

VOLTAGE

(Digit 12)

208/230v

(5)

460v

(6)

575v

(1)

208/230v

(5)

460v

(6)

575v

(1)

208/230v

(5)

460v

(6)

575v

(1)

UNIT

STATIC

OPTION

(Digit 10)*

Medium (2) 230 5.8 60 1725 1.7 6.7

High (3) 230 7.9 60 1725 2.4 9.1

Medium (2) 460 2.9 60 1725 1.7 3.3

High (3) 460 4 60 1725 2.4 4.6

Medium (2) 575 3.1 60 1725 1.7 3.6

High (3) 575 3.4 60 1725 2.4 3.9

Medium (2) 230 5.8 60 1725 1.7 6.7

High (3) 230 9.2 60 1725 2.9 10.6

Medium (2) 460 2.9 60 1725 1.7 3.3

High (3) 460 4.6 60 1725 2.9 5.3

Medium (2) 575 3.1 60 1725 1.7 3.6

High (3) 575 4.2 60 1725 3.7 4.8

Medium (2) 230 7.9 60 1725 2.4 9.1

High (3) 230 9.2 60 1725 2.9 10.6

Medium (2) 460 4 60 1725 2.4 4.6

High (3) 460 4.6 60 1725 2.9 5.3

Medium (2) 575 3.4 60 1725 2.4 3.9

High (3) 575 4.2 60 1725 3.7 4.8

VFD1NVLT

(N.VLT)

VFD1NAMP

(N.AMP)

installed and the VFD must be set to the auto mode. The 3 jumpers
are shown on the unit schematic and are connected through a plug
called PL25. These jumpers set the VFD to start enabled, run
enabled, and tie the common bus together. The VFD has 2 LEDs
on its front panel to indicate operating status. See below and VFD
Troubleshooting section for details on VFD faults and alarms. The
VFD faults can be reset with the VFD keypad or through the
ComfortLink controls (AlarmsR.CUR =Yes).

The Green LED on steady indicates power is on the VFD, flashing
Green indicates an alarm condition detected. Alarms are advisory
in nature. These indicate a problem has been detected by the VFD’s
diagnostics but this problem will not require a shutdown.

The Red LED steady or flashing indicates a fault condition is
detected. A fault is a significant internal situation for the VFD or
Motor. Faults will typically shutdown the motor.

VFD Diagnostics (with Keypad)

The drive detects error situations and reports them using:

1. Green and red LEDs on the body of the drive (located under
the keypad)

2. Status LED on the control panel

3. Control panel display

4. The Fault Word and Alarm Word parameter bits (parameters
0305 to 0309)

The form of the display depends on the severity of the error. The user
can specify the severity for many errors by directing the drive to
ignore the error situation, report the situation as an alarm, or report the
situation as a fault.

Faults (Red LED Lit)

The VFD signals that it has detected a severe error, or fault, by:

1. Enabling the red LED on the drive (LED is either steady or
flashing)

2. Setting an appropriate bit in a Fault Word parameter (0305
to 0307)

3. Overriding the control panel display with the display of a
fault code

4. Stopping the motor (if it was on)

5. Sets an appropriate bit in Fault Word parameter 0305--

0307.

The fault code on the control panel display is temporary. Pressing
the MENU, ENTER, UP button or DOWN buttons removes the
fault message. The message reappears after a few seconds if the
control panel is not touched and the fault is still active.

COMFORTLINK CCN POINT (DISPLAY MENU ITEM)

VFD1NFRQ

(N.FRQ)

VFD1NRPM

(N.RPM)

VFD1NPWR

(N.PWR)

Alarms (Green LED Flashing)

For less severe errors, called alarms, the diagnostic display is
advisory. For these situations, the drive is simply reporting that it
had detected something unusual. In these situations, the drive:

1. Flashes the green LED on the drive (does not apply to
alarms that arise from control panel operation errors)

2. Sets an appropriate bit in an Alarm Word parameter (0308
or 0309)

3. Overrides the control panel display with the display of an
alarm code and/or name

Alarm messages disappear from the control panel display after a
few seconds. The message returns periodically as long as the alarm
condition exists.

Correcting Faults

The recommended corrective action for faults is shown in the Fault
Listing Table 27. The VFD can also be reset to remove the fault. If
an external source for a start command is selected and is active, the
VFD may start immediately after fault reset.

To reset a fault indicated by a flashing red LED, turn off the power
for 5 minutes. To reset a fault indicated by a red LED (not
flashing), press RESET from the control panel or turn off the
power for 5 minutes. Depending on the value of parameter 1604
(FAULT RESET SELECT), digital input or serial communication
could also be used to reset the drive. When the fault has been
corrected, the motor can be started.

History

For reference, the last three fault codes are stored into parameters
0401, 0412, 0413. For the most recent fault (identified by
parameter 0401), the drive stores additional data (in parameters
0402 through 0411) to aid in troubleshooting a problem. For
example, a parameter 0404 stores the motor speed at the time of the
fault. To clear the fault history (all of Group 04, Fault History
parameters), follow these steps:

1. In the control panel, Parameters mode, select parameter

0401.

2. Press EDIT.

3. Press the UP and DOWN buttons simultaneously.

4. Press SAVE.

Correcting Alarms

To correct alarms, first determine if the Alarm requires any
corrective action (action is not always required). Use Table 28 to
find and address the root cause of the problem.

58

VFD1MAXA

(MAX.A )

If diagnostics troubleshooting has determined that the drive is
defective during the warranty period, contact ABB Automation
Inc., at 1--800--435--7365, option 4, option 3. A qualified
technician will review the problem with the caller and make a

Table27–FAULTCODES

determination regarding how to proceed. This may involve
dispatching a designated service station (DSS) representative from
an authorized station, dispatching a replacement unit, or advising
return for repair.

FAULT

CODE

FAULT NAME IN PANEL DESCRIPTION AND RECOMMENDED CORRECTIVE ACTION

1

2

3

4 SHORT CIRC Fault current. Check for short---circuit in the motor cable(s) or motor or supply disturbances.

5 OVERLOAD Inverter overload condition. The drive output current exceeds the ratings.

6

7

8

9

10

11 ID RUN FAIL The motor ID run was not completed successfully. Check motor connections.

12

13 RESERVED Not used.

14 EXT FAULT 1 Digital input defined to report first external fault is active. See parameter 3003 EXT ERNAL FAULT 1.

15 EXT FAULT 2 Digital input defined to report second external fault is active. See parameter 3004 EXTERNAL FAULT 2.

16

17

18 THERM FAIL Internal fault. The thermistor measuring the internal temperature of the drive is open or shorted. Contact Carrier.

19

20 OPEX PWR Internal fault. Low voltage condition detected on the OINT board. Contact Carrier.

21 CURR MEAS Internal fault. Current measurement is out of range. Contact Carrier.

22 SUPPLY PHASE Ripple vol tage in the DC link is too high. Check for missing main phase or blown fuse.

23 RESERVED Not used.

24

25 RESERVED Not used.

26 DRIVE ID Internal fault. Configuration block drive ID is not valid.

27 CONFIG FILE Internal configuration file has an error. Contact Carrier.

28

29 EFB CON FILE Error in reading the configuration file for the field bus adapter.

30 FORCE TRIP Fault trip forced by the field bus. See the field bus reference literature.

31 EFB 1 Fault code reserved for the EFB protocol application. The meaning is protocol dependent.

32 EFB 2 Fault code reserved for the EFB protocol application. The meaning is protocol dependent.

33 EFB 3 Fault code reserved for the EFB protocol application. The meaning is protocol dependent.

34

35 OUTP WIRING Error in power wiring suspected. Check that input power wired to drive output. Check for ground faults.

OVERCURRENT

DC OVERVOLT

DEV OVERTEMP

DC OVERVOLT

Al1 LOSS

Al2 LOSS

MOT OVERTEMP

PAN EL LO SS

MOTOR STA LL

EARTH FAULT

UNDERLOAD

OPEX LINK

OVERSPEED

SERIAL 1 ERR

MOTOR PHASE

Output current is excessive. Check for excessive motor load, insufficient acceleration time (parameters 2202
ACCELER TIME 1, default 30 seconds), or faulty motor, motor cables or connections.

Intermediate circuit DC voltage is excessive. Check for static or transient over voltages in the input power supply,
insufficient deceleration time (parameters 2203 DECELER TIME 1, default 30 seconds), or undersized brake chopper
(if present).

Drive heat sink is overheated. Temperature is at or above 115_C (239_F). Check for fan failure, obstructions in the air
flow, dirt or dust coating on the h eat sink, excessive ambient temperature, or excessive motor load.

Intermediate circuit DC voltage is not sufficient. Check for missing phase in the input power supply, blown fuse, or
under voltage on main circuit.

Analog input 1 loss. Analog input value is less than AI1 FLT LIMIT (3021). Check source an d connection for analog
input a nd parameter settings for AI1 FLT LIMIT (3021) and 3001 AI<MIN FUNCTION.

Analog input 2 loss. Analog input value is less than AI2 FLT LIMIT (3022). Check source an d connection for analog
input a nd parameter settings for AI2 FLT LIMIT (3022) and 3001 AI<MIN FUNCTION.

Motor is too hot, as estimated by the drive. Check for overloaded motor. Adjust the parameters used for the estimate
(3005 through 3009). C heck the temperature sensors and Group 35 parameters.

Panel communication is lost and either drive is in local control mode (the control pan el displays LOC), or drive is in
remote control mode (REM) and is parameterized to accept start/stop, direction or reference from the control panel.
To correct check the communication lines and connections. Check parameter 3002 PANEL COMM ERROR,
parameters in Group 10: Command Inputs and Group 11:Reference Select (if drive operation is REM).

Motor or process stall. Motor is operating in the stall region. Check for excessive load or insufficient motor power.
Check parameters 3010 through 3012.

The load on the input power system is ou t of balance. Check for f au lts in the motor or motor cable. Verify that motor
cable does not exceed maximum specified length.

Motor load is lower than expected. Check for disconnected load. Check parameters 3013 UNDERLOAD FUNCTION
through 3015 UNDERLOAD CURVE.

Internal fault. A communication---related problem has been detected between the OMIO and OINT boards. Contact
Carrier.

Motor speed is greater than 120% of the larger (in magnitude) of 2001 MINIMUM SPEED or 2002 MAXIMUM SPEED
parameters. C heck parameter settings for 2001 and 2002. C heck adequacy of motor braking torque. Check
applicability of torque control. Check brake chopper and resistor.

Field bus communication has timed out. Check fault setup (3018 COMM FAULT FUNC and 3019 COMM FAULT
TIME). Check communication settings (Group 51 or 53 as appropriate). Check for poor connections and/or noise on
line.

Fault in the motor circuit. One of the motor phases is lost. Check for motor fault, motor cable fault, thermal relay fault,
or internal fault.

48/50LC

59

Table 27 — FAULT CODES (cont)

FAULT

CODE

101--- 105 SYSTEM E RROR Error internal to the drive. Contact Carrier and report the error number.

201--- 206 SYSTEM E RROR Error internal to the drive. Contact Carrier and report the error number.

1000

1001 PAR PFA RE FN G Parameter values are inconsistent. Ch eck that 2007 MINIMUM FREQ is negative, when 8123 PFA ENABLE is active.

1002

1003

1004

1005

48/50LC

1006

1007

1008

1009

1010 OVERRIDE/PFA

FAULT NAME IN PANEL DESCRIPTION AND RECOMMENDED CORRECTIVE ACTION

Parameter values are inconsistent. Check for any of the following:
2001 MINIMUM SPEED > 2002 MAXIMUM SPEED
2007 MINIMUM FREQ > 2008 MAXIMUM FREQ

PAR HZ RPM

PAR PFA IOCNF

PAR AI SC AL E

PAR AO SC AL E

PAR PC U 2

PAR EX T R O

PAR FB US

PAR PFA MODE

PAR PC U 1

CONFLICT

2001 MINIMUM SPEED / 9908 MOTOR NOM SPEED is outside of the range: --- 128/+128
2002 MAXIMUM SPEED / 9908 MOTOR NOM SPEED is outside of the range: --- 128/+128
2007 MINIMUM FREQ / 9907 MOTOR NOM FREQ is outside of the range: --- 128/+128
2008 MAXIMUM FREQ / 9907 MOTOR NOM FREQ is outside of the range: --- 128/+128

Parameter values are inconsistent. The number of programmed PFA relays does not match with Interlock
configuration, wh en 8123 PFA ENABLE is active. Check consistency of RELAY OUTPUT parameters 1401 through
1403, and 1410 throu gh 1412. Check 8117 NR OF AUX MOTORS, 8118 AUTOCHANGE INTERV, and 8120
INTERLOCKS.

Parameter values are inconsistent. Check that parameter 1301 AI 1 MIN > 1302 AI 1 MAX and that parameter 1304 AI
2 MIN > 1305 AI 2 MAX.

Parameter values are inconsistent. Check that parameter 1504 AO 1 MIN > 1505 AO 1 MAX and that parameter 1510
AO 2 MIN > 1511 AO 2 MAX.

Parameter values for power control are inconsistent: Improper motor nominal kVA or motor nominal power. Check
the following parameters:

1.1 < (9906 MOTOR NOM CURR * 9905 MOTOR NOM VOLT * 1.73 / PN) < 2.6
Where: PN = 1000 * 9909 MOTOR NOM POWER (if units are kW) or PN = 746
* 9909 MOTOR NOM POWER (if units are HP, e.g., in US)

Parameter values are inconsistent. Check the extension relay module for connection and 1410 through 1412 RELAY
OUTPUTS 4 through 6 have non---zero values.

Parameter values are inconsistent. Check that a parameter is set for field bus control (e.g., 1001 EXT1 COMMANDS
= 10 (COMM)), but 9802 COMM PROT SEL = 0.

Parameter val ues are inconsistent. The 9904 MOTOR CTRL MODE must = 3 (SCALAR SPEED) when 8123 PFA
ENABLE activated.

Parameter values for power control are inconsistent or improper motor nominal frequency or speed. Check for both
of the f ol lowing:
1 < (60 * 9907 MOTOR NOM FREQ / 9908 MOTOR NOM SPEED < 16

0.8 < 9908 MOTOR NOM SPEED / (120 * 9907 MOTOR NOM FREQ / Motor poles) < 0.992

Override mode is enabled and PFA is activated at the same time. This cannot be done because PFA interlocks cannot
be observed in the override mode.

Table 28 – ALARM CODES

ALARM

CODE

2001 --- Reserved

2002 --- Reserved

2003 --- Reserved

2004 DIR LOCK

2005 I/O COMM

2006 Al1 LOS S

2007 Al2 LOS S

2008 PAN EL LO SS

2009 --- Reserved

2010 MOT OVERTEMP

2011 UNDERLOAD

2012 MOTOR STALL Motor is operating in the stall region. This alarm warns that a Motor Stall fault trip may be near.

ALARM NAME

IN PANEL

DESCRIPTION AND RECOMMENDED CORRECTIVE ACTION

The change in direction being attempted is not allowed. Do not attempt to change the direction of motor rotation, or
Change parameter 1003 D IRECTION to allow direction change (if reverse operation is safe).

Field bus communication has timed out. Check fault setup (3018 COMM FAULT FUNC and 3019 COMM FAULT
TIME). Check communication settings (Group 51 or 53 as appropriate). Check for poor connections and/or noise on
line.

Analog input 1 is lost, or value is less than the minimum setting. Check input source and connections. Check the
parameter that sets the minimum (3021) and the parameter that sets the Alarm/Fault operation (3001).

Analog input 2 is lost, or value is less than the minimum setting. Check input source and connections. Check
parameter that sets the minimum (3022) and the parameter that sets the Alarm/Fault operation (3001).

Panel communication is lost and either the VFD is in local control mode (the control panel displays HAND), or the
VFD is in remote control mode (AUTO) and is parameterized to accept start/stop, direction or reference from the
control panel. To correct, check the communication l ines and connections, Parameter 3002 PANEL LOSS, and
parameters in groups 10 COMMAND INPUTS and 11 REFERENCE SELECT (if drive operation is REM).

Motor is hot, based on either the VFD estimate or on temperature feedback. This alarm warns that a Motor Overload
fault trip may be near. Check for overloaded motor. Adjust the parameters used for the estimate (3005 through 3009).
Check the temperature sensors and Group 35 parameters.

Motor load is lower than expected. This alarm warns that a Motor Underload fault trip may be near. Check that the
motor and drive ratings match (motor is NOT undersized for the drive). Check th e settings on para meters 3013 to

3015.

60

Table 28 — ALARM CODES (cont)

ALARM

CODE

2013* AUTO RES ET

2014 AUTOCHANGE

2015 PFA INTERLOCK

ALARM NAME

IN PANEL

DESCRIPTION AND RECOMMENDED CORRECTIVE ACTION

This alarm warns that the drive is about to perform an automatic fault reset, which may start the motor. To
control automatic reset, use parameter group 31 (AUTOMATIC RESET).

This alarm warns that the PFA autochange function is active. To control PFA, use parameter group 81 (PFA) and the
Pump Alternation macro.

This alarm warns that the PFA interlocks are active, which means that the drive cannot start any motor (when
Autochange is used), or a speed regulated motor (when Autochange is not used).

2016 --- Reserved

2017* OFF BUTTON This alarm indicates that the OFF button has been pressed.

2018 PID SLEEP

This alarm warns that the PID sleep function is active, which means that the motor could accelerate when the PID
sleep function ends. To control PID sleep, use parameters 4022 through 4026 or 4122 through 4126.

2019 ID RUN The VFD is performing an ID run.

2020 OVERRIDE Override mode is activated.

2021

2022

START ENABLE 1

MISSING

START ENABLE 2

MISSING

This a larm warns that the Start Enable 1 signal is missing. To control Star t Enable 1 function, use parameter 1608. To
correct, check the digital input configuration and the communication settings.

This a larm warns that the Start Enable 2 signal is missing. To control Star t Enable 2 function, use parameter1609. To
correct, check the digital input configuration and the communication settings.

2023 EMERGENCY STOP Emergency stop is activated.

* This al a r m is not indicated by a relay output, even when the relay output is configured to indicate alarm conditions, parameter 1401 RELAY OUTPUT = 5

(ALARM) or 16 (FLT/ALARM).

Scrolling Marquee Display

This device is the keypad interface used to access rooftop
information, read sensor values, and test the unit. (See Fig. 22.)
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 Navigatort Display

The accessory hand-held Navigator display can be used with
48/50LC units. (See Fig. 23.) 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.

Carrier Comfort Network (CCN)RInterface

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. 24.) 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 Figs. 11 and 12.) 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

MODE

Run Status

Service Test

Temperature

Pressures

Setpoints

Inputs

Outputs

Configuration

Time Clock

Operating Modes

Alarms

Alarm Status

ESCAPE

ENTER

Fig. 22 -- Scrolling Marquee

O

A

la

C06320

C

o

m

f

o

r

t

L

N

in

A

V

I

k

G

A

T

O

T
E

W

L

W

S

E

M

O

Ru

n Sta

S

e

rv

ice

T

em

p

era

P

res

s

ure

S

e

tpo

in

ts

In

pu

ts

O

utp

uts

C

on

fig

u

ra

tion

T

im

e C

lo

ck

p

er

ating

Mod

rm

s

E

N

T

E

R

R

IM

E

1

2

T

.

5

8

5

4

T

.

6

°

F

4

4

T

P

.1

°

F

4

4

.

0

°

F

D

E

Ala

rm

Sta

tus

tu

s

Te

s

t

ture

s

s

E

S

C

es

conductors must be insulated with PVC, PVC/nylon, vinyl, Teflon,
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_Cto60_Cis
required. See Table below 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

Fig. 23 -- Accessory Navigatort Display

C06321

where the cable enters or exits the building (one point per building
only).

48/50LC

61

To connect the unit to the network:

1. Turn off power to the control box.

2. Cut the CCN wire and strip the ends of the red (+), white
(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.

CCN BUS

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.

48/50LC

BUILDING SUPERVISOR

REMOTE
CCN SITE

NETWORK

OPTIONS

AUTODIAL
GATEWAY

TERMINAL

SYSTEM

MANAGER

CL

CL

ROOFTOP

UNIT

ROOFTOP

UNIT

CL

ROOFTOP

UNIT

HEATING/COOLING UNITS

TCU

DAV AI R

TERMINAL

TCU

DAV AIR

TERMINAL

CL

CL

ROOFTOP

UNIT

ROOFTOP

UNIT

TCU

CCN -- Carrier Comfort Network

LEGEND

CL -- ComfortLink Controls
DAV -- Digital Air Volume
HVAC -- Heating, Ventilation, and
Air Conditoning
TCU -- Terminal Control Unit

TO
ADDITIONAL
TERMINALS

DAV FAN
POWERED
MIXING
BOX

®

NON CARRIER

HVAC

EQUIPMENT

COMFORT

CONTROLLER

AIR DISTRIBUTION-DIGITAL AIR VOLUME CONTROL (DAV)

C07030

Fig. 24 -- CCN System Architecture

62

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

Direct drive ECM motors are protected from locked rotor and
over-current through the electronic control module attached to the
motor. In the belt drive application, the VFD serves as the motor
thermal and over-current protection. Refer to Major Component’s
section for more detail on the 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

The ECM motor is protected from locked rotor and over-current
protection through the electronic control module attached to the
motor.

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).

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. TheT-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 --SPT+ Sensor Input.........

TB --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 --SPT+ Sensor Input.......

TB --SPT– Sensor Common........

TB --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. 25 for space temperature averaging with T-55 sensors
only. If the use of one T-56 sensor is required, refer to Fig. 26.

48/50LC

63

RED

T

BLK

RED

BLK

48/50LC

LEGEND

B -- Terminal Block
______ -- Factory Wiring
_ _ _ _ -- Field Wiring

TB1-T55

1

2

TO MAIN
BASE BOARD

TB1-T55

1

2

TO MAIN
BASE BOARD

RED

BLK

SENSOR 1 SENSOR 2 SENSOR 3 SENSOR 4

RED

BLK

RED

BLK

SPACE TEMPERATURE AVERAGING --4 T-55 SENSOR APPLICATION

RED

BLK

BLK

SENSOR 1

RED

RED

BLK

SENSOR 2

RED

BLK

RED

BLK

RED

BLK

SENSOR 3

SENSOR 6SENSOR 5

BLK

SENSOR 4

RED

RED

BLK

RED

BLK

SENSOR 8SENSOR 7 SENSOR 9

SPACE TEMPERATURE AVERAGING --9 T-55 SENSOR APPLICATION

C07032

Fig. 25 -- Space Temperature Sensor Averaging

RED

BLK

TB1-T55

1

2

TO MAIN

BASE

BOARD

RED

BLK

RED

BLK

RED

BLK

RED

BLK

TB1-T55

3

TO MAIN

BASE

BOARD

T-55 SENSOR 1 T-55 SENSOR 2 T-55 SENSOR 3 T-56 SENSOR 4

WHT

C07033

Fig. 26 -- Space Temperature Sensor Averaging with 3 T--55 Sensors and One T--56 Sensor

64

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.

Indoor Air Quality

The indoor air quality (IAQ) sensor (part no. 33ZCSENCO2) is a
field-installed accessory which measures CO
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 IAQ 4--20mA Input.............

TB or COM Sensor Common............

TB or R--2 24vac Output..............

TB or C--2 Common (GND)..............

levels in the air.

2

Outdoor Air Quality

The outdoor air quality (OAQ) sensor is a field-installed accessory
that measures CO
ECB board must be installed and the unit must be configured for
OAQ use by setting Configuration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)

levels in the air. When installing this sensor, an

2

Smoke Detectors

The smoke detectors are field-installed accessories. These detectors
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 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
Configuration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
accessory 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.

Enthalpy Sensors

The enthalpy accessories 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. 11 and Fig. 12 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-installed
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 used to replace the RAT sensor that
is inside the unit’s return air section. 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 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 unit must be
configured by setting Configuration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.

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UNITRH.SW, identifies the normally open or
normally closed status of this input at LOW humidity.

TB or HUM Discrete Input to Board............

TB or TR--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UNITRH.S to YES.

TB or LPWR 24 VDC Loop Power...........

TB or SPRH 4--20mA Input Signal............

48/50LC

65

APPENDIX — LOCAL DISPLAY AND CCN TABLES

MODE — RUN STATUS

ITEM EXPANSION RANGE UNITS

RUN STATUS STATUS DISPLAY

VIEW Auto View of Run Status (VIEW = Display only)

HVAC HVAC Mode Status 1=Disabled

OCC Currently Occupied No/Yes OCCUPIED
SAT Supply Air Temperature xxx..x °F SAT_DISP
ALRM Current Alarms & Alerts xx ALRMALRT
TIME Time of Day xx.xx hh.mm TIMECOPY

VERS Software Version Numbers VERSIONS

MBB CESR131505---xx---xx ( x x --- x x i n t a b l e ) MODEL_NUMBER_01
ECB CESR131249--- xx--- xx MODEL_ NUMBER_02
MARQ CESR131171--- xx---xx MODEL_NUMBER_03
VFD1 FW Version --- xxxxx VFD1_SW
NAVI CESR131227---xx ---xx

MODE Control Modes MODEDISP MODEDISP

SYS Current System Mode 1=Disabled

HVAC Current HVAC Mode 1=Disabled

48/50LC

F. M O D Indoor Fan Mode x IDF_MODE
HV.DN Remote HVAC Mode Disable No/Yes HVACDOWN forcible
EFF . C Cool Setpoint In Effect xx.x °F CSP_EFF
EFF . H Heat Setpoint In Effect xx.x °F HSP_EFF
OCC Currently Occupied No/Yes OCCUPIED forcible
T. O VR Timed Override in Effect No/Yes MODETOVR
LINK Linkage Active No/Yes MODELINK
D.LMT Demand Limit In Effect No/Yes MODEDMDL
C.LOC Compressor OAT Lockout No/Yes COMPLOCK
H.LOC Heat OAT Lockout No/Yes HEATLOCK
OK.EC OK to Use Economizer? No/Yes ECONCOOL

COOL Cooling Status COOLDISP

DMD.C Cooling Demand xxx.x ^F COOL_DMD
AVL.C Available Cooling Stages x AVL CSTGS
REQ.C Requested Cooling Stages x REQCSTGS
MAX.C Max Allowed Cool Stages x MAXCSTGS forcible
LMT.C Max Cool Stage In Effect x CSTGLIMT
F. SP D Commanded Fan Speed xxx % FANSPEED
CMP.A Circuit A Compressor Off/On COMP_A
TG.A Timeguard A xxx sec TIMGD_A
LDR.A Circuit A Loader Off/On LOA DER
TG.L Timeguard Loade r xxx sec TIMGD_L
SST.A Sat. Suction Temp A xxx.x °F SST_A
SSP.A Suction Pressure A xxx.x psig SSP_A
SCT.A Sat. Condenser Temp A xxx.x °F SCT_ A
SCP.A Co ndenser Pressure A xxx.x psig SCP_A

HEAT Heating Status HEATDISP

DMD.H Heating Demand xxx.x ^F HEAT_DMD
AVL.H Available Heating Stages x AVLHSTGS
REQ.H Requested Heating Stages x REQHSTGS
MAX.H Max Allowed Heat Stages x MAXHSTGS forcible
LMT.H Max Heat Stage In Effect x HSTGLIMT
F. SP D Commanded Fan Speed xxx % FANSPEED
HT.1 Heat Stage 1 Relay Off/On HEAT_1
TG.H1 Heat Stage 1 Timeguard xxx sec TIMG D_H1
HT.2 Heat Stage 2 Relay Off/On HEAT_2
TG.H2 Heat Stage 2 Timeguard xxx sec TIMG D_H2

ECON Economizer Status ECONDISP

EC.CP Econo Commanded Position xxx % ECONOCMD
EC.AP Econo Actual Position xxx % ECONOPOS
EC.MP MinPositioninEffect xxx % MIN_POS forcible
IAQ.S IAQ Level (switch) Low/High IAQIN
IAQ IAQ Level (sensor) xxxx IAQ
OAT Outdoor Air Temperature xxx.x °F OA_TEMP
RAT Return Air Temperature xxx.x °F RETURN_T
ENTH Outdoor Enthalpy Switch Low/High ENTHALPY
OAQ OAQ Level (sensor) xxxx OAQ
PE.1 Power Exhaust 1 Relay Off/On PE_1
PE.2 Power Exhaust 2 Relay Off/On PE_2

2=Ventilation
3=Cool
4=Heat

2=Run Enabled
3: Service Test

2=Ventilation
3=Cool
4=Heat

CCN TABLE/

S u b --- T A B L E

CCN POINT

HVACMODE

SYS_MODE

HVACMODE

CCN WRITE

STATUS

66

APPENDIX — LOCAL DISPLAY AND CCN TABLES

MODE — RUN STATUS (cont)

ITEM EXPANSION RANGE UNITS

S.VFD SUPPLY FAN VFD VFD_DATA

VFD1 Status Word 1 NNNNN VFD1STAT
SPD VFD1 Actual Speed % NNN.n % VFD1_SPD
RPM VFD1 Actual Motor RPM NNNNN VFD1RPM
FREQ VFD1 Actual Motor Freq NNN.n VFD1FREQ
AMPS VFD1 Actual Motor Amps NNN.n amps VFD1AMPS
TORQ VFD1 Actual Motor Torque NNNN.n % VFD1TORQ
PWR VFD1 Actual Motor Power NNNN.nn VFD1PWR
VDC VFD1 DC Bus Voltage NNNN volts VFD1VDC
V.OU T VFD1 Output Voltage NNNN volts VFD1VOUT
TEMP VFD1 Transistor Temp (C) NNN VFD1TEMP
RUN.T VFD1 Cumulative Run Time NNNNN hours VFD1RUNT
KWH VFD1 Cumulat ive kWh NNNNN VFD1KWH
LFC VFD1 Last Fault Code NNNNN VFD1LFC

VFD1 DI1 State Open/Close VFD1_DI1

VFD1 DI2 State Open/Close VFD1_DI2

VFD1 DI3 State Open/Close VFD1_DI3

VFD1 DI4 State Open/Close VFD1_DI4

VFD1 DI5 State Open/Close VFD1_DI5

VFD1 DI6 State Open/Close VFD1_DI6

VFD1 AI1 (% of range) NNN.n % VFD1_AI1

VFD1 AI2 (% of range) NNN.n % VFD1_AI2

HRS Component Run Hours STRTHOUR

A1 Compressor A1 Run H ours xxxxx.xx hours HR_A1 forcible
A.LDR Comp A1 Loader Run Hours xxxxx.xx hours HR_A1LDR
IDF1 Indoor Fan 1 Run Hours xxxxx.xx hours HR_IDF1 forcible
IDF2 Indoor Fan 2 Run Hours xxxxx.xx hours HR_IDF2
IDF3 Indoor Fan 3 Run Hours xxxxx.xx hours HR_IDF3
HT.1 Heat Stage 1 Run Hours xxxxx.xx hours HR_HTR_1 forcible
HT.2 Heat Stage 2 Run Hours xxxxx.xx hours HR_HTR_2 forcible

PE.1 Power Exhaust1 Run H ours xxxxx.xx hours HR_PE_1 forcible
PE.2 Power Exhaust2 Run H ours xxxxx.xx hours HR_PE_2 forcible
ALRM Alarm Relay Run Hours xxxxx.xx ho urs HR_ALM forcible
L.ODF Low Amb ODF Run Hours xxxxx.xx hours HR_LAODF forcible

STRT Component Starts

A1 Compressor A1 Starts xxxxxx ST_A1 forcible
A.LDR Comp A1 Loader Starts xxxxxx ST_A1LDR
IDF1 Indoor Fan 1 Starts xxxxxx ST_IDF1 forcible
IDF2 Indoor Fan 2 Starts xxxxxx ST_IDF2
IDF3 Indoor Fan 3 Starts xxxxxx ST_IDF3
HT.1 Heat Stage 1 Starts xxxxxx ST_HTR_1 forcible
HT.2 Heat Stage 2 Starts xxxxxx ST_HTR_2 forcible
PE.1 Power Exhaust 1 Sta rts xxxxxx ST_PE_ 1 forcible
PE.2 Power Exhaust 2 Sta rts xxxxxx ST_PE_ 2 forcible
ALRM Alarm Relay Starts xxxxxx ST_ALM forcible
L.ODF Low Amb ODF Starts xxxxxx ST_LAODF forcible

(ALRMDISP) = CCN only) ALRMDISP

Active Alarm 1 Code xxx ALMCODE1

Active Alarm 2 Code xxx ALMCODE2

Active Alarm 3 Code xxx ALMCODE3

Active Alarm 4 Code xxx ALMCODE4

Active Alarm 5 Code xxx ALMCODE5

Reset All Current Alarms No/Yes ALRESET forcible

Reset Alarm History No/Y es ALHISCLR forcible

CCN TABLE/

S u b --- T A B L E

CCN POINT

CCN WRITE

STATUS

48/50LC

67

APPENDIX — LOCAL DISPLAY AND CCN TABLES

MODE — RUN STATUS (cont)

ITEM EXPANSION RANGE UNITS

(GENERIC = CCN only) GENERIC

(LON_DATA = CCN only) LON_DATA

48/50LC

nviSpaceTemp xxx.x °F NVI_SPT Forcible

nviSetPoint xxx.x °F NVI_SP forcible

nvoSpaceTemp xxx.x °F NVO_SPT

nvoUnitStatus.mode xxxx NVO_MODE

nvoUnitStatus.heat_o ut_p xxx.x % NVO_HPRI

nvoUnitStatus.heat_o ut_s xxx.x % NVO_H SEC

nvoUnitStatus.cool_out xxx.x % NVO_COOL

nvoUnitStatus.econ_out xxx.x % NVO_ECON

nvoUnitStatus.fan_out xxx % NVO_ FAN

nvoUnitStatus.in_alarm xxx NVO_ ALRM

nviSetPtOffset xxx.x ^F NVI_SPTO forcible

nviOutside Te mp xxx.x °F NVI_OAT forcible

nviOutside RH xxxx.x % NVI_OARH forcible

nvoEffectSetPt xxx.x °F NVO_EFSP

nvoOutsideTemp xxxx.x °F NVO_OAT

nvoOutsideRH xxx.x % NVO_OARH

nviSpaceRH xxx.x % NVI_SPRH forcible

nviCO2 xxxxx NVI_CO2 forcible

nvoCO2 xxxxx NVO_CO2

nvoTEMP1 xxx.x °F NVO_SAT

nvoTEMP2 xxx.x °F NVO_RAT

nviPCT1 xxx.x % NVI_RHSP forcible

nvoPCT1 xxx.x % NVO_SPRH

nviDISCRETE1 Off/On NVI_FSD forcible

nviDISCRETE2 No/Yes NVI_OCC forcible

nviDISCRETE3 Off/On NVI_IAQD forcible

nvoDISCRETE1 Off/On NVO_FSD

nvoDISCRETE2 No /Y es NVO_OCC

nvoDISCRETE3 Off/On NVO_IAQD

nciCO2Limit xxxxx NCI_CO2 forcible

nciSetPnts.occupied_cool xxx.x °F NCI_OCSP forcible

nciSetPnts.standby_cool xxx.x °F NCI_ SCSP forcible

nciSetPnts.unoccupd_cool xxx.x °F NCI_UCSP forcible

nciSetPnts.occupied_heat xxx.x °F NCI_OHSP forcible

nciSetPnts.standby_heat xxx.x °F NCI_SHSP forcible

nciSetPnts.unoccupd_heat xxx.x °F NCI_ UHSP forcible

CCN TABLE/

S u b --- T A B L E

CCN POINT

up to 20 points

CCN WRITE

STATUS

68

APPENDIX — LOCAL DISPLAY AND CCN TABLES

MODE — SERVICE TEST

SERVICE TEST

TEMPERATURES STATUS DISPLAY

PRESSURES

ITEM EXPANSION RANGE UNITS CCN TABL E/Su b--- TABLE CCN POINT

TEST Field Service Test Mode Off/On (TEST = display only)

INDP Test Independent Outputs TESTINDP

ECON Economizer Position Test 0 to 100 % S_ECONO

E.CAL Calibrate Economizer Off/On S_ECOCAL

PE.1 Powe r Exhaust 1 Test Off/On S_PE_1

PE.2 Powe r Exhaust 2 Test Off/On S_PE_2

ALRM Alarm Relay Test Off/On S_ALMOUT

FANS Te st F an s TESTFANS

F. SP D Indoor Fan Speed Test 0 to 100 % S_FANSPD

F. MO D IDF Fan Mode 0to7 S_IDFMOD

IDF1 Indoor Fan Test 1 Off/On S_IDF_1

IDF2 Indoor Fan Test 2 Off/On S_IDF_2

IDF3 Indoor Fan Test 3 Off/On S_IDF_3

COOL Test Cooling TESTCOOL

CMP.A Cool A Test Off/On S_COMP_A

LDR_A Cir A Loader T est Off/On S_LOADER

F. SP D Reduced Cool Fan Speed 0 to 100 % S_ FSPDCL

L.ODF Low Amb O DF Test Off/On S_LAODF

HEAT Te s t H e at i ng TESTHEAT

HT.1 Heat Stage 1 Test Off/On S_HEAT_1

HT.2 Heat Stage 2 Test Off/On S_HEAT_2

F. SP D Reduced Heat Fan Speed 0 to 100 % S_FSPDH T

MODE — TEMPERATURES & PRESSURES

ITEM EXPANSION RANGE UNITS

AIR.T Air Temperatures UINPUT

SAT Supply Air Temperature xxx.x °F SAT_DISP

OAT Outdoor Air Temperature xxx.x °F OA_TEMP forcible forcible

SPT Space Temperature xxx.x °F SPACE_T forcible forcible

SPTO Space Temperature Offset xxx.x ^F SPTO forcible forcible

RAT Return Air Temperature xxx.x °F RETURN_T forcible forcible

REF.T Refrigerant Temperatures xxx.x °F

SST.A Sat. Suction Temp A xxx.x °F SST_A

SCT.A Sat. Condenser Temp A xxx.x °F SCT_A

SSP.A Suction Pressure A xxx.x psig SSP_A

SCP.A Condenser Pressure A xxx.x psig SCP_A

CCN TABLE/
S u b --- T A B L E

CCN POINT

CCN WRITE

STATUS

DISPLAY WRITE

STATUS

48/50LC

MODE — SETPOINTS

ITEM EXPANSION RANGE UNITS DEFAULT CCN TABLE/Sub ---TA BLE CCN POINT

SETPOINTS SETPOINT CONFIGURATION

OCSP Occupied Cool Setpoint 55 t o 80 °F 78 SET_PNT OCSP

UCSP Unoccupied Cool Setpoint 65 to 95 °F 85 UCSP

OHSP Occupied Heat Setpoint 55 to 80 °F 68 OHSP

UHSP Unoccupied Heat Setpoint 40 to 80 °F 60 UHSP

GAP Heat --- Cool Setpoint Gap 2to10 ^F 5 HCSP_GAP

STO.R SPT Offset Range (+/ ---) 0to5 ^F 5 SPTO_RNG

RH.SP Space RH Occupied SP 30 to 100 % 50 SPRH _SP

RH.UN Space RH Unoccupie d SP 30 to 100 % 80 SPRH _USP

RH.DB Space RH Deadband 2to20 % 8 SPRH_DB

RH.HB Dehum Heat SP Deadband --- 5 t o 5 ^F 2 RH_HSPDB

LCSP Low Cool SAT Setpoint 55 to 75 °F 60 LCSASP

HCSP High Cool SAT Setpoint 50 to 70 °F 55 HC SASP

CCSP Comfort SAT Setpoint 40 to 70 °F 55 CFSASP

69

APPENDIX — LOCAL DISPLAY AND CCN TABLES

MODE — INPUTS

ITEM EXPANSION RANGE UNITS

INPUTS STATUS DISPLAY

STAT Thermostat Inputs UINPUT

Y1 Thermost at Y1 Input Off/On Y1 forcible forcible

Y2 Thermost at Y2 Input Off/On Y2 forcible forcible

W1 Thermostat W1 Input Off/On W1 forcible forcible

W2 Thermostat W2 Input Off/On W2 forcible forcible

G Thermostat G Input Off/On G forcible forcible

GEN.I General Inputs General Inputs

FIL.S Filter Status Switch Clean/Dirty FILTSTAT forcible

FAN.S Fan Status Switch Off/On FAN_STAT forcible

FDWN Fire Shutdown Swit ch Off/On FIREDOWN forcible

ENTH Outdoor Enthalpy Switch Low/High ENTHALPY forcible forcible

RM.OC Remote Occupancy Switch Off/On REM_OCC forcible forcible

HUM Space Humidity Switch Lo w/High HUM_STAT forcible forcible

IGC.F IGC Fan Request Off/On IDF_FDBK

CS.A1 Current Sensing A1 Off/On CS_A1

AIR.Q Air Quality Inputs

IAQ.S IAQ Level (switch) Low/High IAQIN forcible forcible

48/50LC

IAQ IAQ Level (sensor) xxxx IAQ forcible forcible

OAQ OAQ Level (sensor) xxxx OAQ forcible forcible

SP.RH Space Humidity Sensor xxx.x % SPRH forcible forcible

MODE — OUTPUTS

ITEM EXPANSION RANGE UNITS

OUTPUTS STATUS DISPLAY

FANS Fan Out puts UOUTPUT

F. SP D Commanded Fan Speed xxx % FANSPEED

IDF1 Indoor Fan Speed Relay 1 Off/On IDF_1

IDF2 Indoor Fan Speed Relay 2 Off/On IDF_2

IDF3 Indoor Fan Speed Relay 3 Off/On IDF_3

COOL Cool Outputs

CMP.A Circuit A Compressor Off/On COMP_A

LDR.A Circuit A Loader Off/On LOADER

L.ODF Low Ambient Outdoor Fan Off/On LA_ODF

HEAT Heat Outputs

HT.1 Heat Stage 1 Relay Off/On HEAT_1

HT.2 Heat Stage 2 Relay Off/On HEAT_2

ECON Economizer Outputs

EC.CP Econo Commanded Position 0 to 100 % ECONOCMD forcible forcible

EC.AP Econo Actual Position 0 to 100 % ECONOPOS

PE.1 Power Exhaust 1 Relay Off/On PE_1 forcible

PE.2 Power Exhaust 2 Relay Off/On PE_2 forcible

ALRM Alarm Relay Off/On ALMOUT forcible

CCN TABLE/

S u b --- T A B L E

CCN TABLE/
S u b --- T A B L E

CCN POINT

CCN POINT

CCN WRITE

STATUS

CCN WRITE

STATUS

DISPLAY WRITE

STATUS

DISPLAY WRITE

STATUS

70

APPENDIX — LOCAL DISPLAY AND CCN TABLES

MODE — CONFIGURATIONS

ITEM EXPANSION RANGE UNITS DEFAULT

CONFIGURATION SERVICE

DISP Display Configuration DISPLAY

METR Metric Display Off/On Off DISPUNIT 12

LANG Language Selection 0=English

PROT Password Enable Disable/Enable Enable PA SS_EB L 12

PSWD Service Password 0000 to 9999 1111 PAS SWO RD 12

TEST T est Display LEDs Off/On Off (display only, not in table) DISPTEST 12

UNIT Unit Configuration UNIT

S.DLY Startup Delay 10 to 600 se c 30 STARTDLY 12

U.CTL Unit Control Type 2=Thermostat

T. CTL Thermostat Control Type 0=Adaptive

FN.SW Fan Status Switch 0=No Switch

FL.SW Filter Status Switch 0=No Switch

FS.SW Fire Shutdown Switch 0=No Switch

RM.SW Remote Occupancy Switch 0=No Switch

SAT.T SAT Settling Time 10 to 900 sec 240 SAT_SET 12

RAT.S RAT Sensor Installed No/Yes Ye s RAT_SENS 12

RH.S RH Sensor on OAQ Input No/Yes No RH_OAQ 12

RH.SW Space Humidity Switch 0=No Switch

TCS.C Temp Cmp Strt Cool Factr 0to60 mins 0 TCSTCOOL 13

TCS.H TempCmpStrtHeatFactr 0to60 mins 0 TCSTHEAT 13

I.FAN INDOOR FAN CONFIG AFAN_CFG

FTYP Indoor Fan Type 1=LEN VFD

NSPD Number of Speeds 2or3 0 NUM_ SPDS 14

SMT.F Smart Fan Control No/Yes Ye s

OC.FN FanOnWhenOccupied No/Yes Ye s OCC_ FAN 15

IDF.F Shut Down on IDF Failure No/Yes Ye s FATALFAN 15

FS.MX Supply Fan Maximum

F. SP 1 Supply Fan Speed 1 0 to 100 70 (04)

F. SP 2 Supply Fan Speed 2 0 to 100 87 (04)

F. SP 3 Supply Fan Speed 3 0 to 100 92 (04)

FS.VN Fan Speed --- Ventilation 0 to 100 % 50 FSPDVENT 15

S.VFD SUPPL Y FAN VFD CONFIG 15

N.VLT VFD1 Nominal Motor Volts 0 to 999 volts 230

N.AMP VFD1 Nominal Motor Amps 0 to 999 amps See VFD Motor Parameters

N.FRQ VFD1 Nominal Motor Freq 10 to 500 60 VFD1NFRQ 57

N.RPM VFD1 Nominal Motor RPM 50 to 30000 1725 VFD1NRPM 57

N.PWR VFD1 Nominal Motor HPwr 0 to 500 See VFD Motor Parameters

MAX.A VFD1 Maximum Amps 0 to 999 amps See VFD Motor Parameters

M.DIR VFD1 Motor Direction 0=FORWARD

ACCL VFD1 Acceleration Time 0 to 1800 secs 30 VFD1ACCL 57

DECL VFD1 Deceleration Time 0 to 1800 secs 10 VFD1DECL 57

SW.FQ VFD1 Switching Frequency 0to3 1 VFD1SWFQ 57

Speed

1=Spanish
2=French
3=Portuguese

3=Space Sensor

1=1 Stage Y1
2=2 Stage Y1
3=Digital

1=Normal Open
2=Normal Closed

1=Normal Open
2=Normal Closed

1=Normal Open
2=Normal Closed

1=Normal Open
2=Normal Closed

1=Normal Open
2=Normal Closed

2=ECM

80 to 100 100 SPEEDMAX 15

1=REVERSE

0 LANGUAGE 12

2 CTL_TYPE 12

0 STATTYPE 12

0 FANSTCFG 12

0 FILSTCFG 12

0: no FIOP
1: FIOP

0 REMOCCFG 12

0 HUMSTCFG 12

1
2: Direct Drive Fan

No (Direct Drive Fan)

57 (05 & 06)

71 (05)
69 (06)

84 (05 & 06)

460
575

(T able 26 )

(T able 26 )

(T able 26 )

0 VFD1MDIR 57

CCN TABLE/
S u b --- T A B L E

CONFIGURATION

CCN POINT

SHTDNCFG 12

FAN_TYPE 14

SMARTFAN 15

SPEED1 15

SPEED2 15

SPEED3 15

VFD1NVLT 57

VFD1NAMP 57

VFD1NPWR 57

VFD1MAXA 57

PAG E

NO.

48/50LC

71

APPENDIX — LOCAL DISPLAY AND CCN TABLES

MODE — CONFIGURATION (cont)

ITEM EXPANSION RANGE UNITS DEFAULT

COOL Cooling Configuration COOL_CFG 11

N.STG Number of Stages 1to2 2 NUM_ST AG

MRT.C Compressor Min On Time 120 to 999 sec 180 MIN_ON 16

MOT.C Compressor Min Off Time 300 to 999 se c 300 MIN_OFF 16

RST.C Runtime to Reset Strikes 120 to 999 sec 300 MIN_ON_S 26

C.DEC Cool Stage Decrease Time 120 to 999 sec 300 STAGEDEC 16

C.INC Cool Stage Increase Time 120 to 999 sec 450 STAGEINC 16

FOD.C Fan--- off Delay, Mech Cool 0 to 600 sec 75 COOL_FOD 15

FTT Fan Transition Time 60 to 600 sec 75 FANTRANT 17

ALM.N Alert Each Strike No/Yes sec 480 ALM_NOW 27

CA.LO CircuitALockoutTemp 0 to 100F °F 0 OATLCMPA 16

LA.SP Low Ambie nt ODF

D.CMP Diagnose Comp Safety No/Yes Ye s DIAGCOMP 27

MX.SA Max Suction Change CirA 0 to 100 PSIG 4 MAXDS SP A 27

CS.A1 Current Sensing A1 Disable/Enable Disable A1_SENSE 28

DHUM Dehum Co ntrol Type 0=No Control

48/50LC

SAT Supply Air Temperature

SA.PD SAT Cool Demand (+)

SA.ND SAT Cool Demand (--- )

SAT.U Minimum SAT Upper Level 35.0 to 65.0 °F 52 SATMIN_H 16

SAT.L Minimum SAT Lower Level 35.0 to 65.0 °F 40 SATMIN_L 16

SPT Space Temperature

CL.PD SPT Cool Demand (+)

CL.ND SPT Cool Demand (---)

C.LAG Cool Thermal Lag Factor 0to5 1 COOL_LAG

SST Low Suction Control

SST.O Suction OK Temperature 10 to 50 °F 18 SSTOK 29

SST.1 Low Suction --- Level 1 10 to 50 °F 20 SSTLEV1 28

SST.2 Low Suction --- Level 2 5to50 °F 15 SSTLEV2 28

SST.3 Low Suction --- Level 3 0to50 °F 10 SSTLEV3 28

CK.DL Delay On Low SST Check 0 to 300 sec 0 SSTCKDLY

FLSU FanLowSuctionTemp 28 to 50 °F 32 FANLOSUC 17

HEAT Heating Configuration HEAT_CFG

HT.TY Type of Heat Installed 0=No Heat

N.HTR Number of Heat Stages 1to2 2 (all except below)

MRT.H Heat Minimum On Time 60 to 999 sec 120 HMIN_ON 19

MOT.H Heat Minimum Off Time 60 to 999 sec 120 HMIN_OFF 19

H.DEC Heat Stage Decrease Time 120 to 999 sec 300 HSTAGDEC 19

H.INC Heat Stage Increase Time 120 to 999 sec 450 HSTAGINC 19

FOD.E Fan--- off Delay, Elect Heat 10 to 600 sec 30 ELEC_FOD 15

FOD.G Fan --- off Delay, Gas Heat 45 to 600 sec 45 GAS_FOD 15

HT.LO Heating Lockout Temp 40 to 125 °F 75 OATLHEAT 18

SAT

SAT.H SAT Heat Mode Sensing Disable/Enable Disable SAT_HEAT 18

SAM.L Maximum SAT Lower Level 85 to 200 °F 140 SATMAX_L 18

SAM.U Maximum SAT Upper Level 85 to 200 °F 160 SATMAX_H 18

SPT Space Temperature

HT.PD SPT H eat Demand (+)

HT.ND SPT Heat Demand (--- )

H.LAG Heat Thermal Lag Factor 0to5 1 HEAT_LAG

ECON Economizer Configuration ECON_CFG

EC.EN Economizer Installed No/Yes No: no FIOP

E.CTL Economizer Control Type 1=Dig/Position

MP.25 Econ Min at 25% Fanspeed 0 to 100 % 0 MINP_25 22

Setpoint

Level

Level

Level

Level

Level

Level

0to80 °F 40 LAODF_SP 17

1=Max Dehum
2=Max Comfort

0.5 to 10 ^F 1 SAT_POS

--- 1 0 t o --- 0 . 5 ^F --- 1 SAT_NEG

0.5 to 5 ^F 1 DEM_POS

--- 5 t o --- 0 . 5 ^F --- 1 DEM_NEG

1=Gas
2=Electric

0.5 to 5 ^F 1 HDEM_POS

--- 5 t o --- 0 . 5 ^F --- 1 HDEM_NEG

2=Dig/Command
3=Analog Ctrl

0 DEHUMCTL 17

0 (50 series with no electric heat)
1(48series)
2 (50 series with electric heat)

1 (48 series Low Nox or singl e

phase unit))

1 (50 series with low or medium

heat)

1 (50 series 04--- 05 with high heat)

Yes : FI OP

1 ECON_CTL 21

CCN TABLE/

S u b --- T A B L E

CCN POINT

HEATTYPE 18

NUM_HEAT 19

ECONO 19

PAG E

NO.

72

APPENDIX — LOCAL DISPLAY AND CCN TABLES

MODE — CONFIGURATION (cont)

ITEM EXPANSION RANGE UNITS DEFAULT

ECON (cont ) Economizer Configuration ECON_CFG

MP.50 Econ Min at 50% Fanspeed 0 t o 100 % 0 MINP_50 22

MP.75 Econ Min at 75% Fanspeed 0 t o 100 % 0 MINP_75 22

MP.MX Econ Min at Max Fanspeed 0 to 100 % 30 MINP_ MAX 22

MP.LO Econ Min at Low Fanspeed 0 to 100 % 40 MINP_LOW 21

MP.VT Econ Min at Vent Fanspeed 0 to 100 % 50 MINPVENT 21

EC.MX Econo Cool Max Position 0 to 100 % 100 ECONOMAX

M.ANG Min Actuator Ctrl Angle 75 to 90 88 MINANGLE 21

EH.LO Econo Cool Hi Temp Limit 40 to 100 °F 65 OATLECLH 22

EL.LO Econo Cool Lo Temp Limit --- 30 to 50 °F 0 OATLECLL 22

DF.DB Diff Dry Bulb Control 0=Disable

UEFC Unoccupied Free Cooling 0=Disabled

FC.TM Free Cool PreOcc Time 1 to 9999 mins 120 UEFCTIME 22

FC.LO Free Cool Low Temp Limit ---30 to 70 °F 50 OATLUEFC 22

PE.EN Power Exhaust Installed No/Yes No PE_ENABL 23

PE.1 PE Stage1 Econo Position 0 to 100 % 40 PE1_POS 23

PE.2 PE Stage2 Econo Position 0 to 100 % 75 PE2_POS 23

PE1C Power Exhaust Stage1

PE2C Power Exhaust Stage2

IDF.C Indoor Fan Max Speed

EN.SW Enthalpy Switch 0=No Switch

E.TRV Economizer Travel Time 5 to 300 secs 150 ECONOTRV

E.MXB Bottom Stage Max Econo 0 to 100 % 50 ECONMAXB 22

LOG .F Log Title 24 Faults No/Yes T24LOGFL 20

EC.MD T24 Econ Move Detect 1to10 T24ECMDB 20

EC.ST T24 Econ Move SAT Test 10 to 20 T24ECSTS 20

S.CHG T24 Econ Move SAT Change 0to5 T24SATMD 20

E.SOD T 24 E co n R AT --- O AT Dif f 5to20 T24RA T DF 20

E.CHD T24 Heat/Cool End Delay 0to60 T24CHDLY 20

ET.MN T24 T est Mininmum Pos. 0to50 T24TSTMN 20

ET.MX T24 Test Maximum Pos. 50 to 100 T24TSTMX 20

AIR.Q Air Quality Config. IAQ_CFG

IA.CF IAQ Analog Input Config 0=No IAQ

IA.FN IAQ Analog Fan Config 0=Never

II.CF IAQ Switch Input Config 0=No IAQ

II.FN IAQ Switch Fan Config 0=Never

AQ.MN Econo Min IAQ Position 0 to 100 % 10 IAQMINP 23

OVR.P IAQ Override Position 0 to 100 % 100 IAQOVPOS 24

OA.CF OAQ Analog Input Config 0=No OAQ

OAQ.L OAQ Lockout Limit 0 to 5000 600 OAQLOCK 22

AQD.L AQ Differential Low 0 to 5000 100 DAQ_LOW 23

AQD.H AQ Differential High 0 to 5000 700 DAQ_HIGH 23

DF.ON FanOnAQDifferential 0 to 5000 600 DAQFNON 24

DF.OF Fan Off AQ Differential 0 to 5000 200 DAQFNOFF 24

I.4M IAQ Sensor Value at 4mA 0 to 5000 0 IAQ_4MA 23

I.20M IAQ Sensor Value at 20mA 0 to 5000 2000 IAQ_20MA 23

O.4M OAQ Sensor Value at 4mA 0 to 5000 0 OAQ_4MA 24

O.20M OAQ Sensor Value at 20mA 0 to 5000 2000 OAQ_20MA 24

H.4M RH Sensor Value at 4 mA 0to50 % 0 RH_4MA 17

H.20M RH Sensor Value at 20mA 60 to 100 % 100 RH_20MA 17

CFM

CFM

CFM

1=RAT --- 0° F
2=RAT --- 2° F
3=RAT --- 4° F
4=RAT --- 6° F

1=Unoccpied
2=PreOccupancy

0 to 15000 CFM 800 PE1_CFM

0 to 15000 CFM 0 PE2_CFM

500 to 15000 CFM 1200 (04)

1=Normal Open
2=Normal Closed

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

1=DCV
2=Lockout OAQ

0=Disable DIFFBULB 22

2 UEFC_CFG 22

1600 (05)
2000 (06)

0: no FIOP
1: FIOP

0: no FIOP
1: FIOP

0 IAQANFAN 24

0 IAQINCFG 23

0 IAQINFAN 24

0 OAQANCFG 24

CCN TABLE/
S u b --- T A B L E

CCN POINT

IDF_CFM 7

ENTHLCFG 9

IAQANCFG 9

PAG E

NO.

48/50LC

73

APPENDIX — LOCAL DISPLAY AND CCN TABLES

MODE — CONFIGURATION (cont)

ITEM EXPANSION RANGE UNITS DEFAULT

ALM.O Alarm Relay Config. ALM_CFG

A.SPC SPT/SPRH Sensor Failure No/Yes Ye s SPACE_AL

A.SRT SAT/RAT Sensor Failure No/Yes Ye s SATRATAL

A.OAT OAT Thermistor Failure No/Yes Ye s OAT_AL

A.CS Current Sensor Failure No/Yes No CS_AL

A.CMP Compressor Failure No/Yes Ye s COMP_AL

A.CKT Refrig Circuit Failure No/Yes Ye s CKT_AL

A.SSP SSP Transducer Failure No/Yes Ye s SSP_AL

A.SCT SCT Thermistor Failure No/Yes Ye s SCT_AL

A.FAN Indoor Fan Failure No/Yes Yes FAN_AL

A.FIL Dirty Filter No/Yes Yes FILT_AL

A.TST Thermostat Failure No/Yes Yes TSTAT_AL

A.ECO Economizer Failure No/Yes Yes ECON_AL

PID PID Configurations PID_CFG

EC.P Economizer PID --- kP 0.00 to 99.90 2.5 ECONO_P

EC.I Economizer PID --- kI 0.00 to 99.90 0.12 ECONO_I

EC.D Economizer PID --- kD 0.00 t o 99.90 1 ECONO_D

EC.DT Economizer PID --- rate 10.00 to 180.00 secs 15 ECONO_DT

48/50LC

EC.DB Economizer PID Deadband 0to25 % 3 ECONBAND

LK.P Linkage Staging PID --- kP 0.00 to 99.90 10 LINK_ P

LK.I Linkage Staging PID --- kI 0.00 to 99.90 5 LINK_I

LK.D Linkage Staging PID --- kD 0.00 to 99.90 5 LINK_D

LK.DT Linkage Staging PID - -- rate 10.00 to 180.00 secs 30 LINK_DT

(GENERIC = CCN only) GENERICS

TRIM Sensor Calibra tion (CCN TRIM --- see

SPT.C Space Temp Calibration ---30 to 130 °F 39

SPT.T Space Temp Trim ---30 to 30 ^F 0 39

SAT.C Supply Air Temp Calib. --- 30 to 130 °F 39

SAT.T Supply Air Temp Trim --- 30 to 30 ^F 0 12

RAT.C Return Air Temp Calib. --- 30 to 130 °F 39

RAT.T Return Air Temp Trim --- 30 to 30 ^F 0 39

CCN CCN Configuration CCN CONFIGURATION

CCN.A CCN Element Number 1 to 239 1 48_ 50_LC CCNADD 25

CCN.B CCN Bus Number 0 to 239 0 CCNBUS 25

BAUD CCN Baud Rate 1=2400

BROD CCN Broadcast Config. BRODEFS

B.TIM CCN Time/Date Broadcast No/Yes No CCNBC 25

B.OAT CCN OAT Broadcast No/Yes No OATBC 25

B.GS Global Schedule Broadcst No/Yes No GSBC 25

B.ACK CCN Broadcast Ack’er No/Yes No CCNBCACK 25

POINT 01 Definition Point_01

POINT 02 Definition Point_02

POINT 03 Definition Point_03

POINT 04 Definition Point_04

POINT 05 Definition Point_05

POINT 06 Definition Point_06

POINT 07 Definition Point_07

POINT 08 Definition Point_08

POINT 09 Definition Point_09

POINT 10 Definition Point_10

POINT 11 Definition Point_11

POINT 12 Definition Point_12

POINT 13 Definition Point_13

POINT 14 Definition Point_14

POINT 15 Definition Point_15

POINT 16 Definition Point_16

POINT 17 Definition Point_17

POINT 18 Definition Point_18

POINT 19 Definition Point_19

POINT 20 Definition Point_20

2=4800
3=9600
4=19200
5=38400

3 CCNBAUDD 25

CCN TABLE/

S u b --- T A B L E

Maintenance Display)

CCN POINT

PAG E

NO.

74

APPENDIX — LOCAL DISPLAY AND CCN TABLES

MODE — CONFIGURATION (cont)

ITEM EXPANSION RANGE UNITS DEFAULT

SCH.O CCN Schedule Overrides SCHEDOVR

SCH.N Schedule Number 0 = Always Occupied

HOL.G Accept Global Holidays No /Y es No HOLIDAYT 25

OV.TL Override Time Limit 0to4 hours 4 OTL 25

OV.EX Timed Override Hours 0to4 hours --- OVR_EXT 25

OV.SP SPT Override Enabled No /Y es Yes TIMEOVER 26

LDSH CCN LOADSHED CONFIG. LOADSHED

S.GRP Loadshed Group Number 0to16 0 SHED_NUM 26

R.MXC Redline Max Cool Stages 0to3 2 MAXCREDL 26

S.MXC Loadshed Max Cool Stages 0to3 2 MAXCSHED 26

R.MXH Redline Max Heat Stages 0to2 2 MAXHREDL 26

S.MXH Loadshed Max Heat

Stages

1 --- 6 4 = Loc a l S che dul e
65--- 99 = Global Schedule

0to2 2 MAXHSHED 26

0 SCHEDNUM 25

CCN TABLE/

S u b --- T A B L E

CCN POINT

PAG E

NO.

48/50LC

75

APPENDIX — LOCAL DISPLAY AND CCN TABLES

MODE — TIME CLOCK

ITEM EXPANSION RANGE UNITS DEFAULT

TIME CLOCK CONFIGURATION

TIME Time of Day TIME

TIME Hour and Minute xx.xx hh.mm TIME

DATE Current Date

MNTH Month of Year J anuary, February , ...,

DOM Day of Month 1to31 DOM

YEAR Ye ar xxxx YOCDISP

DAY Day of Week Monday, Tuesday, ...,

DST Daylight Savings Config. BRODEFS (continued)

December

Sunday

CCN TABLE/
S u b --- T A B L E

CCN POINT

MOY

DOWDISP

STR.M Start Month January , February, ...,

STR.W Start Week 1to5 2 STARTW

STR.D Start Day 1to7 7 STARTD

M.ADD Minutes to Add 0to90 60 MINADD

STP.M Stop Month January, February, ...,

48/50LC

STP.W Stop Week 1to5 1 STOPW

STP.D Stop Day 1to7 7 STOPD

M.SUB Minutes to Subtract 0to90 60 MINSUB

SCH.L Occupancy Schedule (SCH.L = Display only)

PER.x Occupancy Period x

OCC.x Occupied From 00.00 to 23.59 hh.mm 00.00 PERxOCC

UNC.x Occupied To 00.00 to 23.60 hh.mm 00.00 PERxUNC

MON.x Monday in Period Yes /No No PERxMON

TUE.x Tuesday in Period Yes /No No PERxTUE

WED.x Wednesday in Period Yes /N o No PERxWED

THU.x Thursday in Period Ye s/ No No PERxTHU

FRI.x Friday in Period Yes /No No PERxFRI

SAT.x Saturday in Period Yes /No No PERxSAT

SUN.x Sunday in Period Ye s/ No No PERxSUN

HOL.x Holiday in Period Ye s/ No No PERxHOL

(repeat up to x=8 Periods)

(OCCFECS = CCN only) OCCDEFCS

Timed Override Hours x hours O V R --- E X T

Period x DOW (MTWTFSSH) xxxxxxxx 00000000 DOWx

Occupied From 00.00 to 24.00 hh.mm 00.00 OCCTODx

Occupied To 00.00 to 24.00 hh.mm 00.00 UNOCTODx

HOL.L Holiday Schedule HOLIDAY

HOL.x Holiday x HOLDYxxS

MON.x Holiday Start Month 1to12=Januaryto

DAY.x Holiday Start Day 1to31 0 HOLDAYxx

LEN.x Holiday Duration (days) 1to99 0 HOLLENxx

(repeat up to x=9 Holidays) (repeat up to

December

December

December

3 STARTM

11 STOPM

(repeat up to x=8
Peri ods)

0 HOLMONxx

xx=30 Holidays)

CCN ONLY TABLES

ITEM EXPANSION RANGE UNITS DEFAULT

(ALARMDEF = CCN only) ALARMDEF

Alarm Routing Control 00000000 to 11111111 11000000 ALRM_CNT

Equipment Priorit y 0to7 5 EQP_TYPE

Comm Failure Retry Time 1 to 240 min 10 RETRY_TM

R e --- A l a r m T i m e 1 to 255 min 180 RE--- ALARM

AlarmSystemName up to 8 alphanum 48_50_LC ALRM_NAM

(CTLRID = CCN only) C TLR --- I D

Device Name: 48_50_LC

Description: text string

Location: text string

Software Part Number: CESR131505--- XX---XX

Model Number:

Serial Number:

Reference Number:

CCN TABLE/
S u b --- T A B L E

76

CCN POINT

APPENDIX — LOCAL DISPLAY AND CCN TABLES

MODE — OPERATING MODES

ITEM EXPANSION RANGE UNITS

OPERATING MODES MAINTENANCE

MODE Control Modes MODES

SYS Unit operation disabled

HVAC HVAC Operation Disabled

F. MO D Indoor Fan Mode x IDF_MODE
F. OV R Fan Override in Effect No /Y es FAN_OVR
HV.DN Remote HVAC Mode Disable No/Yes HVACDOWN forcible
EFF . C Cool Setpoint In Effect xx.x °F CSP_EFF
EFF . H Heat Setpoint In Effect xx.x °F HSP_EFF
OCC Currently Occupied No/Yes OCCUPIED forcible forcible
T. O VR Timed Override in Effect No /Y es MODETOVR
LINK Linkage Active No/Yes MODELINK
D.LMT Demand Limit In Effect No/Yes MODEDMDL
C.LOC Compressor OAT Lockout No/Yes COMPLOCK
H.LOC Heat OAT Lockout No/Y es HEATLOCK
OK.EC OK to Use Economizer? No/Yes ECONCOOL

COOL Cool Mode Diagnostic COOLDIAG

COOL In Cooling Mode? No/Yes IN_COOL
OK.CL OK to Select Cool Mode? No/Yes OKTOCOOL
MS.TG Mode Select Timeguard xxx secs COOLMSTG
OK.EC OK to Use Economizer? No/Yes ECONCOOL
OK.MC OK to Use Compressors? No/Yes MECHCOOL
C.LOC Compressor OAT Lockout No/Yes COMPLOCK
CA.LO CircuitALockoutTemp xxx °F OATLCMPA
F. MO D Indoor Fan Mode x IDF_MODE
F. SP D Commanded Fan Speed NNN % FANSPEED
AVL.C Available Cooling Stages x AVLCSTGS
REQ.C Requested Cooling Stages x REQCSTGS
LMT.C Max Cool Stage In Effect x CSTGLIMT
ACT.C Actual Cooling Stages x ACTCSTGS
CMP.A Circuit A Compressor(s) Off/On COMP_ A
LDR.A Circuit A Loader Off/On LOADER
L.ODF Low Ambient Outdoor Fan Off/On LA_ ODF
ST.A Circuit A Strikes x ASTRIKES
ST.L Cir A Loader Strikes x LSTRIKES
HPS.A Ckt A Hi Pres Sw Check No/Yes INHPSCKA
LSST FanLowSuctionState No/Yes LOW _SS T
LS.CT Low SST Count xxx LO _SSTCT
FLLO Full Load Lockout No/Yes FL_LKOUT
FLSU FanLowSuctionTemp 10 to 50 °F FANLOSUC
SAT Supply Air Temperature

SAT Supply Air Temperature xxx.x °F SAT_DISP
SA.DM Supply Air Temp Demand xxx.x ^F SAT_DMD
SA.PD SAT Cool Demand (+) Level xx.x ^F SAT_POS
SA.ND SAT Cool Demand (--- ) Level xx.x ^F SAT_NEG
SAT.U Minimum SAT Upper Level xx.x °F SATMIN_H
SAT.L Minimum SAT Lower Level xx.x °F SATMIN_L
SA.TR Supply Air d/dt (F/min) xxxx.x SATTREND
SA.DR SAT Delta Reference Temp xxx.x °F SAT_REF

SPT Space Temperature

SPT Space Temperature xxx.x °F SPACE_T forcible forcible
DMD.C Cooling Demand xxx.x ^F COOL_DMD
TRD.C Cool Demand d/dt (F/min) xxx.x CLDTREND
CL.PD SPT Cool Demand (+) Level xx.x ^F DEM_POS
CL.ND SPT Cool Demand (---) Level xx.x ^F DEM_NEG
C.LAG Cool Thermal Lag Factor x.x COOL_LAG

DHUM Dehumidification

HUM Space Humidity Switch Low/High HUM_STAT forcible forcible
SP.RH Space Humidity Sensor xxx.x % SPRH forcible forcible
AVL.R Available Dehum Stages x AVLRSTGS
REQ.R Requested Dehum Stages x REQRSTGS
ACT.R Actual Dehum Stages x ACTRSTGS

Unit operation enabled
Service test enabled

Ventilation (fan ---only)
Cooling
Free Cooling
Unoccupied Free Cooling
Dehumidification
Dehum Cooling
Heating

CCN TABLE/

S u b --- T A B L E

DISPLAY

CCN POINT

SYS_MODE_TEXT1
SYS_MODE_TEXT2
(table only)
SYS_MODE_TEXT3
(table only)

HVACMODE_TEXT_1
HVACMODE_TEXT_2
(table only)
HVACMODE_TEXT_3
(table only)

CCN

WRITE

STATUS

DISPLAY

WRITE

STATUS

48/50LC

77

48/50LC

APPENDIX — LOCAL DISPLAY AND CCN TABLES

MODE — OPERATING MODES (cont)

ITEM EXPANSION RANGE UNITS

HEAT Heat Mode Diagnostic HEATDIAG

HEAT In Heating Mode? No/Yes IN_HEAT
OK.HT OK to Select Heat Mode? No/Yes OKTOHEAT
MS.TG Mode Select Timeguard xxx secs HEATMSTG
H.LOC Heat OAT Lockout No/Y es HEATLOCK
HT.LO Heating Lockout Temp xxx °F OATLHEAT
IGC.F IGC Fan Request Off/On IDF_FDBK
F. MO D Indoor Fan Mode x IDF_MODE
F. SP D Commanded Fan Speed xxx % FANSPEED
AVL.H Available Heating Stages x AVLHSTGS
REQ.H Requested Heating Stages x REQHSTGS
LMT.H Max Heat Stage In Effect x HSTGLIMT
ACT.H Actual Heating Stages x ACTHSTGS
HT.1 Heat Stage 1 Relay Off/On HEAT_1
HT.2 Heat Stage 2 Relay Off/On HEAT_2
SAT Supply Air Temperature

SAT.H SAT Heat Mode Sensing Disable/Enable SAT_HEAT
SAT Supply Air Temperature xxx.x °F SAT_DISP
SAM.L Maximum SAT Lower Level xxx.x °F SATMAX_L
SAM.U Maximum SAT Upper Level xxx.x °F SATMAX_H

SPT Space Temperature

SPT Space Temperature xxx.x °F SPACE_T forcible forcible
DMD.H Heating Demand xxx.x ^F HEAT_DMD
TRD.H Heat Demand d/dt (F/min) xxx.x HTDTREND
HT.PD SPT Heat Demand (+) Level xx.x ^F HDEM_POS
HT.ND SPT Heat Demand (---) Level xx.x ^F HDEM_NEG
H.LAG Heat Thermal Lag Factor x.x HEAT_LAG

ECON Economizer Diagnostic ECONDIAG

EC.EN Economizer Installed No/Yes ECONO
OK.EC OK to Use Economizer? No/Yes ECONCOOL
OCC Currently Occupied No/Yes OCCUPIED forcible forcible
F. MO D Indoor Fan Mode x IDF_MODE
F. SP D Commanded Fan Speed xxx % FANSPEED
COOL In Cooling Mode? No/Yes IN_COOL
OAT Outdoor Air Temperature xxx.x °F OA_TEMP forcible forcible
RAT Return Air Temperature xxx.x °F RETURN_T forcible forcible
E.LOC Econo Cool OAT Lockout No/Yes ECONLOCK
D.LOC Econo Diff Dbulb Lockout No/Yes DFDBLOCK
EH.LO Econo Cool Hi Temp Limit xxx °F OATLECLH
EL.LO Econo Cool Lo Temp Limit xxx °F OATLECLL
FC.LO Free Cool Low Temp Limit xxx °F OATLUEFC
EN.LO Econo Cool Enth Lockout No/Yes ENTHLOCK
EC.MX Econo Cool Max Position xxx % ECONOMAX
AQ.DV IAQ DCV Mode No/Yes IN_IAQDV
AQ.MN Econo Min IAQ Position xxx % IAQMINP
AQ.OV IAQ Override Mode No/Yes IN_IAQOV
OVR.P IAQ Override Position xxx % IAQOVPOS
AQ.LO OAQ Lockout Mode No/Yes IN_OAQLO
OAQ.L OAQ Lockout Limit xxxx OAQLOCK
LP.OV Lo Refrig Press Override No/Yes IN_LPOV
EC.CP Econo Commanded Position xxx % ECONOCMD forcible forcible
EC.AP Econo Actual Position xxx % ECONOPOS
EC.MP MinPositioninEffect xxx % MIN_POS forcible forcible
C.ANG Actuator Control Angle xx.x CTLANGLE
E.CAL Economizer Calibrating No/Yes ECOINCAL

DMD.L DEMAND LIMITING DMDL

D.LMT Demand Limit In Effect No/Yes MODEDMDL
LMT.C Max Cool Stage In Effect x CSTGLIMT
LMT.H Max Heat Stage In Effect x HSTGLIMT
REDL Redline Activated No/Yes MODEREDL
SHED Loadshed Activated No/Yes MODESHED
MAX.C Max Allowed Cool Stages x MAXCSTGS
MAX.H Max Allowed Heat Stages x MAXHSTGS

( D isp l a y T R I M --­see Configuration)

Sensor Calibra tion TRIM

Space Temp Calibration ---30 to 130 °F SPT_CAL forcible
Space Temp Trim --- 30 to 30 ^F SPT_OFF forcible
Supply Air Temp Calib. --- 30 to 130 °F SAT_CAL forcible
Supply Air Temp Trim --- 30 to 30 ^F SAT_OFF forcible
Return Air Temp Calib. ---30 to 130 °F RAT_CAL forcible
Return Air Temp Trim --- 30 t o 30 ^F RAT_OFF forcible

CCN TABLE/

S u b --- T A B L E

CCN POINT

CCN

WRITE

STATUS

DISPLAY

WRITE

STATUS

78

APPENDIX — LOCAL DISPLAY AND CCN TABLES

MODE — OPERATING MODES (cont)

ITEM EXPANSION RANGE UNITS

(LINKDATA = CCN only) CCN --- Linkage LINKDATA

Supervisory Element # xxx S U P E --- A D R
Supervisory Bus xxx S U P E --- B U S
Supervisory Block Number xxx BLOCKNUM
Average Occup. Heat Stp. xxxx.x °F AOHS
Average Occup. Cool Stp. xxxx.x °F AOCS
Average Unocc. Heat Stp. xxxx.x °F AUHS
Average Unocc. Cool Stp. xxxx.x °F AUCS
AverageZoneTemperature xxxx.x °F AZT
Average Occup. Zone Temp xxxx.x °F AOZT
Linkage System Occupied? No/Y es LO CC
Next Occupied Day ”Mon”, ”Tue”, ..., ”Sun” 3 --- cha r t ex t LNEXTOCD
Next Occupied Time xx:xx hh:mm LNEXTOCC forcible
Next Unoccupied Day ”Mon”, ”Tue”, ..., ”Sun” 3 --- cha r t ex t LNEXTUOD
Next Unoccupied Time xx:xx hh:mm LNEXTUNC forcible
Last Unoccupied Day ”Mon”, ”Tue”, ..., ”Sun” 3 --- c ha r t e xt LLASTUOD
Last Unoccupied Time xx:xx hh:mm LLASTUNC forcible

(OCCDEFM = CCN only) Occupancy Supervisory OCCDEFM

Current Mode (1=Occup) 0,1 MODE
CurrentOccupPeriod# 0to8 PER_NO
T i me --- O v e r r i d e i n E f f e ct No/Yes OVERLAST
Time--- Override Duration 0to4 hours OVR_HRS
Current Occupied Tiime xx.xx hh:mm STRTTIME
Current Unoccupied Time xx.xx hh:mm ENDTIME

Next Occupied Day NXTOCDAY
Next Occupied Time xx.xx hh:mm NXTOCTIM
Next Unoccupied Day NXTUNDAY
Next Unoccupied Time xx.xx hh:mm NXTUNTIM
Previous Unoccupied Day PRVUNDAY
Previous Unoccupied Time xx.xx hh.mm PRVUNTIM

CCN TABLE/

S u b --- T A B L E

CCN POINT

CCN

WRITE

STATUS

DISPLAY

WRITE

STATUS

48/50LC

MODE — ALARMS

ITEM EXPANSION RA NGE DEFAULT

ALARMS ALARMS

R.CUR Reset All Current Alarms Ye s/No No ALRESET forcible forcible

R.HIS Reset Alarm History Yes /N o No ALHISCLR forcible forcible

CURR Currently Active Alarms

alarm# text string ALARM01C --- ALARM25C

(repeat up to 25 alarms)

HIST Alarm History ALARM HISTORY

alarm# a lar m # --- m m/d d /y y --- hh . mm --- t e xt s t ri n g

(repeat up to 20 Alarms)

CCN TABLE/
S u b --- T A B L E

MAINTENANCE
DISPLAY

CCN POINT

CCN

WRITE

STATUS

DISPLAY

WRITE

STATUS

79

CONTROL SET POINT AND CONFIGURATION LOG

MODEL NO.:

SERIAL NO.:

DATE:

TECHNICIAN:

SOFTWARE VERSIONS

MBB: CESR131505----_ _

ECB: CESR131249----_ _

MARQ: CESR131171----_ _

INDICATE UNIT SETTINGS BELOW

CONTROL TYPE: Thermostat/T55 Space Temp./T--56 Space Temp./T--58 Space Temp.

SET POINT Cooling Occupied: Unoccupied:

Heating Occupied: Unoccupied:

MODE — CONFIGURATION

ITEM EXPANSION RANGE UNITS DEFAULT

CONFIGURATION SERVICE

DISP Display Configuration DISPLAY

48/50LC

METR Metric Display Off/On Off DISPUNIT

LANG Language Selection 0=English

PROT Password Enable Disable/Enable Enable PAS S_ EBL

PSWD Service Password 0000 to 9999 1111 PASSW ORD

TEST Test Display LEDs Off/On Off (display only, not in table) DISPTEST

UNIT Unit Configuration UNIT

S.DLY Startup Delay 10 to 600 sec 30 STARTDLY

U.CTL Unit Control Type 2=Thermostat

T. CTL Thermo stat Control Type 0=Adaptive

FN.SW Fan Status Switch 0=No Switch

FL.SW Filter Stat us Switch 0=No Switch

FS.SW Fire Shutdow n Switch 0=No Switch

RM.SW Remote Occupancy Switch 0=No Switch

SAT.T SAT Set tling Time 10 to 900 sec 240 SAT_SET

RAT.S RAT Sensor Installed No/Yes Ye s RAT_SEN S

RH.S RH Senso r on OAQ Input No/Yes No RH_OAQ

RH.SW Space Humidity Switch 0=No Switch

TCS.C Tem p Cmp Strt Cool Factr 0to60 mins 0 TCSTCOOL

TCS.H TempCmpStrtHeatFactr 0to60 mins 0 TCSTH EAT

1=Spanish
2=French
3=Portuguese

3=Space Sensor

1=1 Stage Y1
2=2 Stage Y1
3=Digital

1=Normal Open
2=Normal Closed

1=Normal Open
2=Normal Closed

1=Normal Open
2=Normal Closed

1=Normal Open
2=Normal Closed

1=Normal Open
2=Normal Closed

0 LANGUAGE

2 CTL_TYPE

0 STATTYPE

0 FANSTCFG

0 FILSTCFG

0: no FIOP
1: FIOP

0 REMOC-

0 HUMSTCF G

CCN TABLE/
S u b --- T A B L E

CONFIGURATION

CCN

POINT

SHTDNCFG

CFG

ENTRY

80

MODE — CONFIGURATION (cont)

ITEM EXPANSION RANGE UNITS DEFAULT

I.FAN INDOOR FAN CONFIG AFAN_CFG

FTYP Indoor Fan Type 1=LEN VFD

NSPD Number of Speeds 2or3 0 NUM_SPDS

SMT.F Smart Fan Control No/Yes Ye s

OC.FN FanOnWhenOccupied No/Yes Ye s OCC_FAN

IDF.F Shut Down on IDF Failure No/Yes Yes FATALFAN

FS.MX Supply Fan Maximum Speed 80 to 100 100 SPEEDMAX

F. SP 1 Supply Fan Speed 1 0 to 100 70 (04)

F. SP 2 Supply Fan Speed 2 0 to 100 87 (04)

F. SP 3 Supply Fan Speed 3 0 to 100 92 (04)

FS.VN Fan Speed --- Ventilation 0 to 100 % 50 FSPDVENT

S.VFD SUPPLY FAN VFD CONFIG

N.VLT VFD1 Nominal Motor Volts 0 to 999 volts 230

N.AMP VFD1 Nominal Motor Amps 0 to 999 amps See VFD Motor Param eters

N.FRQ VFD1 Nominal Motor Freq 10 to 500 60 VFD1NFRQ

N.RPM VFD1 Nominal Motor RPM 50 to 30000 1725 VFD1NRPM

N.PWR VFD1 Nominal Motor HPwr 0 to 500 See VFD Motor Parameters

MAX.A VFD1 Maximum Amps 0 to 999 amps See VFD Motor Parameters

M.DIR VFD1 Motor Direction 0=FORWARD

ACCL VFD1 Acceleration Time 0 to 1800 secs 30 VFD1ACCL

DECL VFD1 Deceleration Time 0 to 1800 secs 10 VFD1DECL

SW.FQ VFD1 Switching Frequency 0to3 1 VFD1SWFQ

COOL Cooling Configuration COOL_CFG

N.STG Number of Stages 1to2 2 NUM_ST AG

MRT.C Compressor Min On Time 120 t o 999 sec 180 MIN_ ON

MOT.C Compressor Min Off Time 300 to 999 sec 300 MIN_ OFF

RST.C Runtime to Reset Strikes 120 to 999 se c 300 MIN_ON_S

C.DEC Cool Stage Decrease Time 120 to 999 sec 300 ST AGEDEC

C.INC Cool Stage Increase Time 120 to 999 sec 450 STAGEINC

FOD.C Fan--- off Delay, Mech Cool 0 to 600 sec 75 COOL_FOD

FTT Fan Transition Time 60 to 600 sec 480 FANTRANT

ALM.N Alert Each Strike No/Yes Yes ALM_NOW

CA.LO CircuitALockoutTemp 0 to 100F °F 0 OATLCM PA

LA.SP Low Ambient ODF

D.CMP Diagnose Comp Safety No/Yes Ye s DIAGCOMP

MX.SA Max Suction Change CirA 0 to 100 PSIG 4 MAXDSSP A

CS.A1 Current Sensing A1 Disable/Enable Disable A1_SENSE

DHUM Dehum Control Type 0=No Control

SAT Supply Air Temperature

SA.PD SAT Cool Demand (+)

SA.ND SAT Cool Demand (--- )

SAT.U Minimum SAT Upper Level 35.0 to 65.0 °F 52 SATMIN_H

SAT.L Minimum SAT Lower Level 35.0 to 65.0 °F 40 SATMIN_L

SPT Space Temperature

CL.PD SPT Cool Demand (+)

CL.ND SPT Cool Demand (--- )

C.LAG Cool Thermal Lag Factor 0to5 1 COOL_LAG

SST Low Suction Control

SST.O Suction OK Temperature 10 to 50 °F 18 SSTOK

SST.1 Low Suction --- Level 1 10 to 50 °F 20 SSTLEV1

SST.2 Low Suction --- Level 2 5to50 °F 15 SSTLEV2

SST.3 Low Suction --- Level 3 0to50 °F 10 SSTLEV3

CK.DL Delay On Low SST Check 0 to 300 sec 0 SSTCKDLY

FLSU FanLowSuctionTemp 28 to 50 °F 32 FANLOSUC

Setpoint

Level

Level

Level

Level

2=ECM

1=REVERSE

0to80 °F 40 LAODF_ SP

1=Max Dehum
2=Max Comfort

0.5 to 10 ^F 1 SAT_POS

--- 1 0 t o --- 0 . 5 ^F --- 1 SAT_NEG

0.5 to 5 ^F 1 DEM_POS

--- 5 t o --- 0 . 5 ^F --- 1 DEM_NEG

1
2: Direct Drive Fan

No (Direct Drive Fan)

57 (05 & 06)

71 (05)
69 (06)

84 (05 & 06)

460
575

(T able 26 )

(T able 26 )

(T able 26 )

0 VFD1MDIR

0 DEHUMCTL

CCN TABLE/
S u b --- T A B L E

CCN

POINT

FAN_TYPE

SMARTFAN

SPEED1

SPEED2

SPEED3

VFD1NVLT

VFD1NAMP

VFD1NPWR

VFD1MAXA

ENTRY

48/50LC

81

MODE — CONFIGURATION (cont)

ITEM EXPANSION RANGE UNITS DEFAULT

HEAT Heating Configuration HEAT_CFG

HT.TY Type of Heat Installed 0=No Heat

N.HTR Number of Heat Stages 1to2 2 (all except below)

MRT.H Heat Minimum On Time 60 to 999 sec 120 HMIN_ON

MOT.H Heat Minimum Off Time 60 to 999 sec 120 HMIN_OFF

H.DEC Heat Stage Decrease Time 120 to 999 sec 300 HSTAGDEC

H.INC Heat Stage Increase Time 120 to 999 sec 450 HSTAGINC

FOD.E Fan--- off Delay, Elect Heat 10 to 600 sec 30 ELEC_FOD

FOD.G Fan--- off Delay, Gas Heat 45 to 600 sec 45 GAS_FOD

HT.LO Heating Lockout Temp 40 to 125 °F 75 OATL HEA T

SAT

SAT.H SAT Heat Mode Sensing Disable/Enable Disable SAT_HEAT

SAM.L Maximum SAT Lower Level 85 to 200 °F 140 SATMAX_L

SAM.U Maximum SAT Upper Level 85 to 200 °F 160 SATMAX_H

SPT Space Temperature

48/50LC

HT.PD SPT Heat Demand (+)

HT.ND SPT Heat Demand ( --- )

H.LAG Heat Thermal Lag Factor 0to5 1 HEAT_LAG

ECON Economizer Configuration ECON_CFG

EC.EN Economizer Installed No/Yes No: no FIOP

E.CTL Economizer Control Type 1=Dig/Position

MP.25 Econ Min at 25% Fanspeed 0 to 100 % 0 MINP_25

MP.50 Econ Min at 50% Fanspeed 0 to 100 % 0 MINP_50

MP.75 Econ Min at 75% Fanspeed 0 to 100 % 0 MINP_75

MP.MX Econ Min at Max Fanspeed 0 to 100 % 30 MINP_MAX

MP.LO Econ Min at Low Fanspeed 0 to 100 % 40 MINP_LOW

MP.VT Econ Min at Vent Fanspeed 0 to 100 % 50 MINPVENT

EC.MX Econo Cool Max Position 0 to 100 % 100 ECONO-

M.ANG Min Actuator Ctrl Angle 75 to 90 88 MINANGLE

EH.LO Econo Cool Hi Temp Limit 40 to 100 °F 65 OATLECL H

EL.LO Econo Cool Lo Temp Limit --- 30 to 50 °F 0 OATLE CL L

DF.DB Diff Dry Bulb Control 0=Disable

UEFC Unoccupied Free Cooling 0=Disabled

FC.TM Free Cool PreOcc Time 1 to 9999 mins 120 UEFCTIME

FC.LO Free Cool Low Temp Limit --- 30 t o 70 °F 50 OATLUEFC

PE.EN Power Exhaust Installed No/Yes No PE _ENABL

PE.1 PE Stage1 Econo Position 0 to 100 % 40 PE1_POS

PE.2 PE Stage2 Econo Position 0 to 100 % 75 PE2_POS

PE1C Power Exhaust Stage1

PE2C Power Exhaust Stage2

IDF.C Indoor Fan Max Speed

EN.SW Enthalpy Switch 0=No Switch

E.TRV Economizer Travel Time 5 to 300 secs 150 ECONOTRV

E.MXB Bottom Stage Max Econo 0 to 100 % 50 ECONMAXB

LOG .F Log Title 24 Faults No/Yes T24LOGFL

EC.MD T24 Econ Move Detect 1to10 T24E CM DB

EC.ST T24 Econ Move SAT T est 10 to 20 T24ECSTS

S.CHG T24 Econ Move SAT Change 0to5 T24SATMD

E.SOD T 24 E c on R AT --- O AT D if f 5to20 T24RATDF

E.CHD T24 Heat/Cool End Delay 0to60 T24CHDLY

ET.MN T24 T est Mininmum Pos. 0to50 T24TSTMN

ET.MX T24 Test Ma ximum Pos. 50 to 100 T24TSTMX

Level

Level

CFM

CFM

CFM

1=Gas
2=Electric

0.5 to 5 ^F 1 HDEM_POS

--- 5 t o --- 0 . 5 ^F --- 1 HDEM_NEG

2=Dig/Command
3=Analog Ctrl

1=RAT --- 0° F
2=RAT --- 2° F
3=RAT --- 4° F
4=RAT --- 6° F

1=Unoccpied
2=PreOccupancy

0 to 15000 CFM 800 PE1_CFM

0 to 15000 CFM 0 PE2_CFM

500 to 15000 CFM 1200 (04)

1=Normal Open
2=Normal Closed

0 (50 series with no electric heat)
1(48series)
2 (50 series with electric heat)

1 (48 series Low Nox or singl e

phase unit)

1 (50 series with low or medium

heat)

1 (50 series 04--- 05 with high heat)

Yes : FI OP

1 ECON_CTL

0=Disable DIFFBULB

2 UEFC_CFG

1600 (05)
2000 (06)

0: no FIOP
1: FIOP

CCN TABLE/
S u b --- T A B L E

CCN

POINT

HEATT YPE

NUM_HEAT

ECONO

MAX

IDF_CFM

ENTHLCFG

ENTRY

82

MODE — CONFIGURATION (cont)

ITEM EXPANSION RANGE UNITS DEFAULT

AIR.Q Air Quality Config. IAQ_CFG

IA.CF IAQ Analog Input Config 0=No IAQ

IA.FN IAQ Analog Fan Co nfig 0=Never

II.CF IAQ Switch Input Config 0=No IAQ

II.FN IAQ Switch Fan Config 0=Never

AQ.MN Econo Min IAQ Position 0 to 100 % 10 IAQMINP
OVR.P IAQ Override Position 0 t o 100 % 100 IAQOVPOS

OA.CF OAQ Analog Input Config 0=No OAQ

OAQ.L OAQ Lockout Limit 0 to 5000 600 OAQLOCK

AQD.L AQ Differential Low 0 to 5000 100 DAQ_L OW
AQD.H AQ Differential High 0 to 5000 700 DAQ_HIGH

DF.ON FanOnAQDifferential 0 to 5000 600 DAQFNON
DF.OF Fan Off AQ Differential 0 to 5000 200 DAQFNOFF

I.4M IAQ Sensor Value at 4mA 0 to 5000 0 IA Q_4MA
I.20M IAQ Sensor Value at 20mA 0 to 5000 2000 IAQ_20MA

O.4M OAQ Sensor Value at 4mA 0 to 5000 0 OAQ_4M A
O.20M OAQ Sensor Value at 20mA 0 to 5000 2000 OAQ_20MA

H.4M RH Sensor Value at 4mA 0to50 % 0 RH_4MA
H.20M RH Sensor Value at 20mA 60 t o 100 % 100 RH_20MA

ALM.O Alarm Relay Config. ALM_CFG

A.SPC SPT/SPRH Sensor Failure No/Yes Yes SPACE_AL

A.SRT SAT/RAT Sensor Failure No/Yes Ye s SATRATAL
A.OAT OAT Thermistor Failure No/Yes Ye s OAT_AL

A.CS Current Sensor Failure No/Y es No CS_AL
A.CMP Compressor Failure No/Yes Ye s COMP_AL

A.CKT Refrig Circuit Failure No/Yes Ye s CKT_AL
A.SSP SSP Transducer Failure No /Y es Ye s SSP_AL

A.SCT SCT Thermistor Failure No /Y es Ye s SCT_AL
A.FAN Indoor Fan Failure No/Yes Ye s FAN_ AL

A.FIL Dirty Filter No/Yes Ye s FILT_AL
A.TST Thermostat Failure No/Yes Yes TSTAT_AL

A.ECO Economizer Failure No /Y es Ye s ECON_AL

PID PID Configurations PID_CFG

EC.P Economizer PID --- kP 0.00 t o 99.90 2.5 ECONO_P
EC.I Economizer PID --- kI 0.00 to 99.90 0.12 ECONO_I

EC.D Economizer PID --- kD 0.00 to 99.90 1 ECONO_D
EC.DT Economizer PID --- rate 10.00 to 180.00 secs 15 ECONO_DT

EC.DB Economizer PID Deadband 0to25 % 3 ECONBAND
LK.P Linkage Staging PID --- kP 0.00 to 99.90 10 LINK_P

LK.I Linkage Staging PID --- kI 0.00 to 99.90 5 LINK_I
LK.D Linkage Staging PID --- kD 0.00 to 99.90 5 LINK_D

LK.DT Linkage Staging PID - -- rate 10.00 to 180.00 secs 30 LINK_DT

(GENERIC = CCN only) GENERICS

POINT 01 Definition Point_01
POINT 02 Definition Point_02

POINT 03 Definition Point_03
POINT 04 Definition Point_04

POINT 05 Definition Point_05
POINT 06 Definition Point_06

POINT 07 Definition Point_07
POINT 08 Definition Point_08

POINT 09 Definition Point_09
POINT 10 Definition Point_10

POINT 11 Definition Point_11
POINT 12 Definition Point_12

POINT 13 Definition Point_13
POINT 14 Definition Point_14

POINT 15 Definition Point_15
POINT 16 Definition Point_16

POINT 17 Definition Point_17
POINT 18 Definition Point_18

POINT 19 Definition Point_19
POINT 20 Definition Point_20

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

1=DCV
2=Lockout OAQ

0: no FIOP
1: FIOP

0 IAQANFAN

0 IAQINCFG

0 IAQINFAN

0 OAQANCFG

CCN TABLE/

S u b --- T A B L E

CCN

POINT

IAQANCFG

ENTRY

48/50LC

83

MODE — CONFIGURATION (cont)

ITEM EXPANSION RANGE UNITS DEFAULT

TRIM Sensor Calibration (CCN TRIM - -- see

SPT.C Space Temp Calibration ---30 to 130 °F

SPT.T Space Temp Trim --- 30 to 30 ^F 0

SAT.C Supply Air Temp Calib. --- 30 to 130 °F

SAT.T Supply Air Temp Trim --- 30 to 30 ^F 0

RAT.C Return Air Temp Calib. --- 30 to 130 °F

RAT.T Return Air Temp Trim ---30 to 30 ^F 0

CCN CCN Configuration CCN CONFIGURA-

CCN.A CCN Element Number 1 to 239 1 48_50_LC CCNADD

CCN.B CCN Bus Number 0 to 239 0 CCNBUS

BAUD CCN Baud Rate 1=2400

BROD CCN Broadcast Config. BRODEFS

B.TIM CCN Time/Date Broadcast No/Yes No CCNBC

B.OAT CCN OAT Broadcast No/Yes No OATBC

B.GS Global Schedule Broadcst No/Yes No GSBC

B.ACK CCN Broadcast Ack’er No/Yes No CCNBCACK

48/50LC

SCH.O CCN Schedule Overrides SCHEDOVR

SCH.N Schedule Number 0 = Always Occupied

HOL.G Accept Global Holidays No/Yes No HOLIDAYT

OV.TL Override Time Limit 0to4 hours 4 OTL

OV.EX Timed Override Hours 0to4 hours --- OVR_EXT

OV.SP SPT Override Enabled No/Yes Ye s TIMEOVER

LDSH CCN LOADSHED CONFIG. LOADSHED

S.GRP Loadshed Group Number 0to16 0 SHED_ NUM

R.MXC Redline Max Cool Stages 0to3 2 MAXCREDL

S.MXC Loadshed Max Cool Stages 0to3 2 MAXCSHED

R.MXH Redline Max Heat Stages 0to2 2 MAXHREDL

S.MXH Loadshed Max Heat

Stages

2=4800
3=9600
4=19200
5=38400

1 --- 6 4 = Loc a l S che d ­ule
65--- 99 = Global
Schedule

0to2 2 MAXHSHED

3 CCNBAUDD

0 SCHED-

CCN TABLE/

S u b --- T A B L E

Maintenance Display)

TION

NUM

CCN

POINT

ENTRY

84

48/50LC

85

48/50LC

Copyright 2014 Carrier Corp. S 7310 W. Morris St. S Indianapolis, IN 46231 Edition Date: 05/14

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

86

C a t a l o g N o : 4 8 --- 5 0 L C --- 4 --- 6 --- C 0 1 T

R e pl a c e s: 4 8 --- 5 0L C --- C 0 1T

UNIT START-UP CHECKLIST

MODEL NO.:

DATE:

SERIAL NO:

TECHNICIAN:

I. PRE-START-UP:

j VERIFY THAT ALL PACKAGING MATERIALS HAVE BEEN REMOVED FROM UNIT
j VERIFY INSTALLATION OF OUTDOOR AIR HOOD
j VERIFY INSTALLATION OF FLUE EXHAUST AND INLET HOOD (48LC ONLY)
j VERIFY THAT CONDENSATE CONNECTION IS INSTALLED PER INSTALLATION INSTRUCTIONS
j VERIFY THAT ALL ELECTRICAL CONNECTIONS AND TERMINALS ARE TIGHT
j VERIFY GAS PRESSURE TO UNIT GAS VALVE IS WITHIN SPECIFIED RANGE (48LC ONLY)
j CHECK GAS PIPING FOR LEAKS (48LC ONLY)
j CHECK THAT INDOOR--AIR FILTERS ARE CLEAN AND IN PLACE
j CHECK THAT OUTDOOR AIR INLET SCREENS ARE IN PLACE
j VERIFY THAT UNIT IS LEVEL
j CHECK FAN WHEELS AND PROPELLER FOR LOCATION IN HOUSING/ORIFICE AND VERIFY SETSCREW IS TIGHT
j VERIFY THAT FAN SHEAVES ARE ALIGNED AND BELTS ARE PROPERLY TENSIONED
j VERIFY THAT SCROLL COMPRESSORS ARE ROTATING IN THE CORRECT DIRECTION
j VERIFY INSTALLATION OF THERMOSTAT/SPACE SENSOR
j VERIFY CONFIGURATION VALUES FOR ELECTRONIC CONTROLS (REFER TO CONTROL SET UP CHECKLIST)
j VERIFY THAT CRANKCASE HEATERS HAVE BEEN ENERGIZED FOR AT LEAST 24 HOURS

II. START-UP

ELECTRICAL

48/50LC

SUPPLY VOLTAGE L1-L2 L2-L3 L3-L1

COMPRESSOR AMPS — UNLOADED L1 L2 L3

—WITHLOADER L1

ELECTRIC HEAT AMPS (IF EQUIPPED) L1 L2 L3

SUPPLY FAN AMPS AT MAX SPEED L1 L2 L3

L2 L3

TEMPERATURES

OUTDOOR-AIR TEMPERATURE F DB (Dry Bulb) F WB (Wet Bulb)

RETURN-AIR TEMPERATURE

COOLING SUPPLY AIR

GAS HEAT SUPPLY AIR (48LC )

ELECTRIC HEA T SUPPLY AIR (50LC)

FDB FWB

FDB FWB

F F

F F

PRESSURES

GAS INLET PRESSURE IN. WG

GAS MANIFOLD PRESSURE STAGE NO. 1

REFRIGERANT SUCTION CIRCUIT A

REFRIGERANT DISCHARGE CIRCUIT A

j VERIFY REFRIGERANT CHARGE USING CHARGING CHARTS

IN.WG STAGENO.2 IN.WG

PSIG CIRCUIT A Superheat degF

PSIG CIRCUIT A Subcooling degF

GENERAL

j ECONOMIZER MINIMUM VENT AND CHANGEOVER SETTINGS TO JOB REQUIREMENTS

87

48/50LC

Copyright 2014 Carrier Corp. S 7310 W. Morris St. S Indianapolis, IN 46231 Edition Date: 05/14

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

88

C a t a l o g N o : 4 8 --- 5 0 L C --- 4 --- 6 --- C 0 1 T

R e pl a c e s: 4 8 --- 5 0L C --- C 0 1T