ICP CCA924GKA100, CCA936GKA100, CCA948GKA100, CCA960GKA100, HCA924GKA100 Installation Guide

Theseinstructionsmustbereadand understoodcompletelybeforeattemptinginstallation.

IMPORTANT:Effective January 1,2015, all split system and packaged air conditioners must be installed pursuant to applicable

regional efficiency standards issued by the Department of Energy.

Safety Labeling and Signal Words

DANGER, WARNING, CAUTION, and
NOTE

The signal words DANGER, WARNING,
CAUTION, and NOTE are used to identify levels of

hazard seriousness. The signal word DANGER is
only used on product labels to signify an immediate

hazard. The signal words WARNING, CAUTION,
and NOTE will be used on product labels and
throughout this manual and other manuals that may

apply to the product.
DANGER - Immediate hazards which will result in

severe personal injury or death.
WARNING - Hazards or unsafe practices which

could result in severe personal injury or death.
CAUTION - Hazards or unsafe practices which

may result in minor personal injury or product or
property damage.

NOTE - Used to highlight suggestions which will
result in enhanced installation, reliability, or

operation.

Signal Words in Manuals

The signal word WARNING is used throughout this

manual in the following manner:

The signal word CAUTION is used throughout this

manual in the following manner:

Signal Words on Product Labeling
Signal words are used in combination with colors

and/or pictures on product labels.

TABLE OF CONTENTS

Safety Considerations ........................... 2

Installation Recommendations ................... 2

Installation ..................................... 2

Start-up Procedure ............................. 7

System Functions & Sequence of Operation ....... 7

Troubleshooting ................................ 8

Status Codes ................................. 11

R-410A Quick Reference Guides ................ 15

ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal

injury and/or death.
Before installing, modifying, or servicing system,

main electrical disconnect switch must be in the OFF
position. There may be more than 1 disconnect

switch. Lock out and tag switch with a suitable warn-

ing label.

CUT HAZARD

Failure to follow this caution may result in personal
injury

Sheet metal parts may have sharp edges or burrs. Use
care and wear appropriate protective clothing and
gloves when handling parts.

421 01 1702 04 03/16/15

SAFETY CONSIDERATIONS

Improper installation, adjustment, alteration, service,

maintenance, or use can cause explosion, fire, electrical shock,
or other conditions which may cause death, personal injury, or

property damage. Consult a qualified installer, service agency, or
your distributor or branch for information or assistance. The

qualified installer or agency must use factory-authorized kits or
accessories when modifying this product. Refer to the individual

instructions packaged with the kits or accessories when installing.
Follow all safety codes. Wear safety glasses, protective clothing,

and work gloves. Use quenching cloth for brazing operations.

Have fire extinguisher available. Read these instructions

thoroughly and follow all warnings or cautions included in

literature and attached to the unit. Consult local building codes

and current editions of the National Electrical Code ( NEC ) NFPA

70. In Canada, refer to current editions of the Canadian electrical
code CSA 22.1.

Figure 1 [ Connecting Tube Installation

NOTE: Avoid contact between tubing and structure

THROUGH THE WALL

SUSPENSION

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

these 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 hazards which could result in

personal injury or death. CAUTION is used to identify unsafe
practices which would 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.

INSTALLATION RECOMMENDATIONS

NOTE: In some cases noise in the living area has been traced to

gas pulsations from improper installation of equipment.

1. Locate unit away from windows, patios, decks, etc. where
unit operation sound may disturb customer.

2. Ensure that vapor and liquid tube diameters are
appropriate for unit capacity.

3. Run refrigerant tubes as directly as possible by avoiding

unnecessary turns and bends.

4. Leave some slack between structure and unit to absorb
vibration.

5.

When passing refrigerant tubes through the wall, seal

opening with RTV or other pliable silicon-based caulk.
(See Fig. 1.)

6.

Avoid direct tubing contact with water pipes, duct work,
floor joists, wall studs, floors, and walls.

7.

Do not suspend refrigerant tubing from joists and studs with

a rigid wire or strap which comes in direct contact with
tubing. (See Fig. 1.)

8.

Ensure that tubing insulation is pliable and completely

surrounds vapor tube.

9.

When necessary, use hanger straps which are 1 in. (25.4

mm) wide and conform to shape of tubing insulation. (See
Fig. 1.)

10.

Isolate hanger straps from insulation by using metal

sleeves bent to conform to shape of insulation.

Outdoor unit contains system refrigerant charge for operation with
AHRI rated indoor unit when connected by 15 ft. (4.57 m) of

field-supplied or factory accessory tubing. For proper unit
operation, check refrigerant charge using charging information
located on control box cover and/or in the Check Charge section

of this instruction.
IMPORTANT: Maximum liquid-line size is 3/8-in. OD for all

residential applications including long line.
IMPORTANT: Always install the factory-supplied liquid-line filter

drier. Obtain replacement filter driers from your distributor or
branch.

INSTALLATION

UNIT OPERATION AND SAFETY HAZARD

Failure to follow this warning could result in personal
injury or equipment damage.

R-410A refrigerant systems operate at higher pressures

than standard R-22 systems. Do not use R-22 service

equipment or components on R-410A refrigerant
equipment.

Specifications for this unit in residential new construction market
require the outdoor unit, indoor unit, refrigerant tubing sets,
metering device, and filter drier listed in presate literature. There

can be no deviation.

Check Equipment and Job Site
Unpack Unit

Move to final location. Remove carton taking care not to damage
unit.

Inspect Equipment

File claim with shipping company prior to installation if shipment is
damaged or incomplete. Locate unit rating plate on unit corner

panel. It contains information needed to properly install unit.
Check rating plate to be sure unit matches job specifications.

Install on a Solid, Level Mounting Pad

If conditions or local codes require the unit be attached to pad, tie
down bolts should be used and fastened through knockouts
provided in unit base pan. Refer to unit mounting pattern in Fig. 2

to determine base pan size and knockout hole location.

2 specificationssubjectto change without notice. 421 01 1702 04

For hurricane tie downs - contact your local distributor for details

and PE (Professional Certification), if required by local authorities.
On rooftop applications, mount on level platform or frame. Place

unit above a load-bearing wall and isolate unit and tubing set
from structure. Arrange supporting members to adequately

support unit and minimize transmission of vibration to building.
Consult local codes governing rooftop applications.

Roof mounted units exposed to winds may require wind baffles.

Consult the Low-Ambient pressure switch installation instructions
for wind baffle construction.

NOTE: Unit must be level to within _+2° (+3/8 in./ft..) per

compressor manufacturer specifications.
Clearance Requirements

When installing, allow sufficient space for airflow clearance,
wiring, refrigerant piping, and service. Allow 30 in. (762 mm)
clearance to service end of unit and 48 in. (1219.2 mm) above

unit. For proper airflow, a 6 in. (152.4 mm) clearance on one side
of unit and 12 in. (304.8 mm) on all remaining sides must be

maintained. Maintain a distance of 24 in. (609.6 mm) between
units. Position so water, snow, or ice from roof or eaves cannot

fall directly on unit.

Figure 2 [

3/8--in. (9.53 ram) Dia.
Tiedown Knockouts in

Basepan(2) Places

Tie Down Knockouts

I

View From Top

UNIT BASE PAN TIEDOWN KNOCKOUT LOCATIONS in. (mm)

Dimension A B C

31-1/2 X 31-1/2

(800 X 800) 9-1/8 (231,8) 6-9/16 (166,7) 24-11/16 (627.1)

35 X 35

(889 X 889) 9-1/8 (231,8) 6-9/16 (166,7) 28-7/16 (722,3)

On rooftop applications, locate unit at least 6 in. (152.4 mm)
above roof surface.

Operating Ambient
The minimum outdoor operating ambient in cooling mode is 55°F

(12.78 °C), and the maximum outdoor operating ambient in

cooling mode is 125°F (51.67°C).

17 SEER product is approved for low ambient cooling operation

down to an ambient as low as 0°F (-17.78°C) with low ambient
accessory kits.

19 SEER product is not approved for low ambient cooling

applications.

This unit is not approved for low ambient cooling
applications.

Make Piping Connections

PERSONAL INJURY AND ENVIRONMENTAL
HAZARD

Failure to follow this warning could result in personal
injury or death.

Relieve pressure and recover all refrigerant before system
repair or final unit disposal.

Use all service ports and open all flow-control devices,
including solenoid valves.

UNIT DAMAGE HAZARD

Failure to follow this caution may result in equipment
damage or improper operation.

Do not leave system open to atmosphere any longer than
minimum required for installation. POE oil in compressor is

extremely susceptible to moisture absorption. Always keep
ends of tubing sealed during installation.

If ANY refrigerant tubing is buried, provide a 6 in. (152.4
mm) vertical rise at service valve. Refrigerant tubing
lengths up to 36 in. (914.4 mm) may be buried without

further special consideration. Do not bury lines more than

36 in. (914.4 mm).

Outdoor units may be connected to indoor section using
accessory tubing package or field-supplied refrigerant grade

tubing of correct size and condition. For tubing requirements
beyond 80 ft/24.38 m, substantial capacity and performance

losses can occur. Following the recommendations in the Long
Line Applications Guideline for Split-System Air Conditioners and

Heat Pumps will reduce these losses. Refer to Table 1 for
accessory requirements. Refer to Table 2 for field tubing

diameters.
There are no buried-line applications greater than 36 in. (914.4

mm).
If refrigerant tubes or indoor coil are exposed to atmosphere, they

must be evacuated to 500 microns to eliminate contamination and
moisture in the system.

Outdoor Unit Connected to Factory Approved Indoor
Unit

Outdoor unit contains correct system refrigerant charge for
operation with factory approved AHRI rated indoor unit when

connected by 15 ft. (4.57 m) of field-supplied or
factory-accessory tubing, and factory supplied filter drier. Check

refrigerant charge for maximum efficiency.

421 01 1702 04 specificationssubjectto change without notice. 3

Table1- AccessoryUsage

REQUIREDFORLOWAMBIENT

COOLINGAPPLICATIONS

(17SEERProductOnly) REQUIREDFORLONGLINE Requiredfor Sea CoastApplica-

Accessory (Below55°F / 12,8°C) APPLICATIONS*(Over80 ft. / 24,38 m) tion (within2 miles/3,22 km)

Crankcase Heater Yes Standardon some units Yes,standard on some units No

Compressor StartAssist Ca-
pacitorand Relay

LiquidLineSolenoid Valve No See Long LineApplications Guideline No

Support Feet Recommended No Recommended

HardShutoff TXV
Evaporator Freeze Thermostat Yes No No

Low-Ambient Pressure Switch Yes No No

Winter Start Control Yes No No

For tubing line sets between 80 and 200 ft, (24.38 and 60,96 m) and/or 20 ff, (6.09 m) vertical differential, refer to Long Line Applications Guideline.

Table 2 - Refrigerant Connections and Recommended Liquid and Vapor Tube Diameters (In.)

UNIT SIZE Diameter Diameter Diameter

"0A724 3/8 3/4 3/4
"0A924 3/8 7/8 7/8

"0A736, "0A936 3/8 7/8 7/8

"0A748, "0A948 3/8 7/8 1-1/8
"0A760, "0A960 3/8 7/8 1-1/8

Units are rated with 25 ft. (7.6 m) of lineset. See Specification sheet for performance data when using different size and length linesets.

Notes:

1. Do not apply capillary tube or fixed orifice indoor coils to these units.

2. For Tubing Set lengths between 80 and 200 ft. (24.38 and 60.96 m) horizontal or 35 ft. (10.7 m) vertical differential 250 ft. (76.2 m) Total Equivalent Length), refer to the Long
Line Applications Guideline.

Install Liquid Line Filter Drier Indoor Refrigerant Tubing Connection Outdoor

UNIT DAMAGE HAZARD

Failure to follow this caution may result in equipment
damage or improper operation.

Installation of filter drier in liquid line is required.
Filter drier must be wrapped in a heat-sinking material
such as a wet cloth while brazing.

Refer to Fig. 3 and install filter drier as follows:

1. Braze 5 in. (127 mm) liquid tube to the indoor coil.

2. Wrap filter drier with damp cloth.

3. Braze filter drier to above 5 in. (127 mm) liquid tube. Flow
arrow must point towards indoor coil.

4. Connect and braze liquid refrigerant tube to the filter drier.

Figure 3 J Liquid Line Filter Drier

Yes(Standardwith factory approved Yes (Standardwithfactory approved in- Yes (Standardwith factoryap-

No No No

indoorunit) door unit) provedindoor unit)

RATEDVAPOR

LIQUID up to 80ft, (24,38 m)*

Connectionand Tube Connection RatedTube

Connect vapor and liquid tubes to fittings on vapor and liquid

service valves (seeTable 2.) Userefrigerant grade tubing.
Sweat Connection

UNIT DAMAGE HAZARD

Failure to follow this caution may result in equipment
damage or improper operation.

Service valves must be wrapped in a heat-sinking
material such as a wet cloth.

Service valves are closed from factory and ready for brazing.
After wrapping service valve with a wet cloth, braze sweat
connections using industry accepted methods and materials.

Consult local code requirements. Refrigerant tubing and indoor
coil are now ready for leak testing. This check should include all

field and factory joints.

Evacuate Refrigerant Tubing and Indoor Coil

UNIT DAMAGE HAZARD

Failure to follow this caution may result in equipment
damage or improper operation.

Never use the system compressor as a vacuum pump.

4 specificationssubjectto change without notice. 421 01 1702 04

Refrigeranttubesandindoorcoilshouldbeevacuatedusingthe
recommendeddeepvacuummethodof 500microns.Ifdeep

vacuum equipmentis notavailable,thealternatetriple
evacuationmethodmaybeusedbyfollowingthespecified

procedure.Ifvacuummustbeinterruptedduringtheevacuation
procedure,alwaysbreakvacuumwithdrynitrogen.

Deep Vacuum Method

The deep vacuum method requires a vacuum pump capable of
pulling a vacuum of 500 microns and a vacuum gage capable of

accurately measuring this vacuum depth. The deep vacuum
method is the most positive way of assuring a system is free of air

and liquid water. (See Fig. 4)

Figure 5 _ Triple Evacuation Sequence

EVACUATE

BREAK VACUUM WITH DRY NITROGEN

WAIT

EVACUATE

BREAK VACUUM WITH DRY NITROGEN

Figure 4 [ Deep Vacuum Graph

IN

SYSTEM

VACUUM TIGHT
TOO WET

TIGHT
DRY SYSTEM

0 1 2 3 4 5 6 7

MINUTES

Triple Evacuation Method
The triple evacuation method should only be used when system

does not contain any water in liquid form and vacuum pump is
only capable of pulling down to 28 inches of mercury (711mm

Hg). Refer to Fig.5 and proceed is as follows:

1. Pull system down to 28 inches of mercury (711mm Hg) and
allow pump to continue operating for an additional 15

minutes.

2. Close manifold valves or valve at vacuum pump and shut
off vacuum pump.

3. Connect a nitrogen cylinder and regulator to system and fill

with nitrogen until system pressure is 2 psig.

4. Close nitrogen valve and allow system to stand for 1 hour.
During this time, dry nitrogen will diffuse throughout the

system absorbing moisture.

5. Repeat this procedure as indicated in Figure 5.

6. After the final evacuate sequence, confirm there are no
leaks in the system. If a leak is found, repeat the entire

process after repair is made.

WAIT

EVACUATE

CHECK FOR TIGHT, DRY SYSTEM I

(IF IT HOLDS DEEP VACUUM

CHARGE SYSTEM

Final Tubing Check
IMPORTANT: Check to be certain factory tubing on both indoor

and outdoor unit has not shifted during shipment. Ensure tubes
are not rubbing against each other or any sheet metal. Pay close

attention to feeder tubes, making sure wire ties on feeder tubes
are secure and tight.

Make Electrical Connections

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal
injury or death.

Do not supply power to unit with compressor terminal box
cover removed.

Be sure field wiring complies with local and national fire, safety,
and electrical codes, and voltage to system is within limits shown

on unit rating plate. Contact local power company for correction of
improper voltage. See unit rating plate for recommended circuit

protection device.
NOTE: Operation of unit on improper line voltage constitutes

abuse and could affect unit reliability. See unit rating plate. Do not
install unit in system where voltage may fluctuate above or below
permissible limits.

NOTE: Use copper wire only between disconnect switch and unit.
NOTE: Install branch circuit disconnect of adequate size per NEC

to handle unit starting current. Locate disconnect within sight from
and readily accessible from unit, per Section 440-14 of NEC.

Route Ground and Power Wires
Remove access panel to gain access to unit wiring. Extend wires

from disconnect through power wiring hole provided and into unit
control box.

I

421 01 1702 04 Specifications subject to change without notice. 5

ELECTRICALSHOCKHAZARD

Failure to follow this warning could result in personal
injury or death.

The unit cabinet must have an uninterrupted or
unbroken ground to minimize personal injury if an
electrical fault should occur. The ground may consist

of electrical wire or metal conduit when installed in
accordance with existing electrical codes.

Connect Ground and Power Wires

Connect ground wire to ground connection in control box for
safety. Connect power wiring to contactor as shown in Fig.6.

Figure 6 J

DISCONNECT
PER N. E. C. AND/OR
LOCAL CODES

Line Power Connections

CONTACTOR

FIELD POWER I

WIRING

@°@

Install Electrical Accessories

Refer to the individual instructions packaged with kits or
accessories when installing.

Check OAT Thermistor and OCT Thermistor
Attachments

Outdoor Air Temperature (OAT) Thermistor is factory installed by
inserting the nibs on either sides of the thermistor body through a

keyhole in the bottom shelf of the control box and locking it in
place by turning it 90 degrees, such that the spherical end of a nib
faces the front of the control box.

Check to make sure the OAT is locked in place. See Fig. 7.

I

Figure 7 J Outdoor Air Thermistor (OAT) Attachment

OATThermistormust be locked
in place with spherical nib end facing

towardsthe front of the control box.

FIELD GROUND

®

WIRING I

Connect Control Wiring
This unit is capable of communication with an Observer Wall

Control, or will operate using standard 24v 2-stage thermostat.

Route 24v control wires through control wiring grommet and

connect leads to control board. When an Observer Wall Control is
available, connect DX+ and DX- connections only. If additional

grounding is needed connect to C terminal. If a 2-stage
thermostat is used, connect to the C, Y1, and Y2 connections.

Refer to the wiring label for further clarification.
Use No. 18 AWG color-coded, insulated (35°C minimum) wire. If

thermostat is located more than 100 ft. (30.48 m) from unit, as
measured along the control voltage wires, use No. 16 AWG
color-coded, insulated wire to avoid excessive voltage drop.

All wiring must be NEC Class 1 and must be separated from

incoming power leads.
Use furnace transformer, fan coil transformer, or accessory

transformer for control power, 24-v/40-va minimum.

NOTE: Use of available 24-v accessories may exceed the

minimum 40-va power requirement. Determine total transformer

load and increase the transformer capacity or split the load with

an accessory transformer as required.

Final Wiring Check

IMPORTANT: Check factory wiring and field wire connections to
ensure terminations are secured properly. Check wire routing to
ensure wires are not in contact with tubing, sheet metal, etc.

Compressor Crankcase Heater

When equipped with a crankcase heater, furnish power to heater
a minimum of 24 hr before starting unit if ambient is less than

65°F (18°C). To furnish power to heater only, set thermostat to
OFF and close electrical disconnect to outdoor unit.

A crankcase heater is required if refrigerant tubing is longer than
80 ft. (24.38 m). Refer to the Long Line Applications Guidelines.

GROUND
LUG

Specifications subject to change without notice. 421 01 1702 04

The Outdoor Coil Temperature (OCT) Thermistor is factory
installed on the liquid tube between the coil assembly and the

liquid service valve. See Fig. 8.
Check to make sure the thermistor is securely attached on the

liquid tube with the clip as shown in Fig. 8.

Figure 8 J Outdoor Coil Thermistor (OCT) Attachment

OCT Thermistor must be
secured tight on the liquid tube.

Airflow Setup with Observer Communicating Furnace
or Fan Coil

When using an Observer Communicating Wall Control and
communicating indoor equipment, airflow is automatically

selected based on equipment size. See Observer Wall Control
Installation Instructions and indoor specification sheet for

available adjustments.
Airflow Setup with Non-Communicating Furnace or

Fan Coil
Two-stage compressor operation requires two different indoor

airflow settings for proper operation. This outdoor unit is designed
for use only with an indoor blower that can be configured for

separate low-stage and high-stage airflow (CFM) levels. Refer to

Product Specifications Sheets for recommended low-stage and
high-stage indoor airflow values.

Refer to indoor unit Installation Instructions to set the indoor

blower for the proper low-stage and high-stage airflow values.

NOTE: Optimal comfort, efficiency, and reliability will only be

achieved when the indoor airflow is properly set for both

low-stage and high-stage operation.

START-UP

UNIT OPERATION AND SAFETY HAZARD
Failure to follow this caution may result in minor personal

injury, equipment damage or improper operation.
To prevent compressor damage or personal injury,

observe the following:

• Do not overcharge system with refrigerant.

• Do not operate unit in a vacuum or at negative
pressure.

• Do not disable low pressure switch in scroll compressor
applications.

• Dome temperatures may be hot.

PERSONAL INJURY HAZARD
Failure to follow this caution may result in personal injury.

Wear safety glasses, protective clothing, and gloves
when handling refrigerant and observe the following:

• Front seating service valves are equipped with
Schrader valves.

ENVIRONMENTAL HAZARD

Failure to follow this caution may result in environmental
damage.

Federal regulations require that you do not vent refrigerant
to the atmosphere. Recover during system repair or final
unit disposal.

Follow these steps to properly start up the system:

1. After system is evacuated, fully open liquid and vapor
service valves.

2. Unit is shipped with valve stem(s) front seated (closed) and
caps installed.

Replace stem caps after system is opened to refrigerant

flow. Replace caps finger-tight and tighten with wrench an
additional 1/12 turn

3. Close electrical disconnects to energize system.

4. Set room thermostat at desired temperature. Be sure set
point is below indoor ambient temperature.

5. Set room thermostat to COOL and fan control to ON or

AUTO mode, as desired. Operate unit for 15 minutes.

Check system refrigerant charge.

Check Charge
Two-stage equipment must be charged in high stage compressor

operation only.

Factory charge amount and desired subcooling are shown on unit
rating plate. Charging method is shown on information plate

inside unit. To properly check or adjust charge, conditions must

421 01 1702 04

Specifications subject to change without notice. 7

be favorable for subcooling charging. Favorable conditions exist
when the outdoor temperature is between 70°F and 100°F

(21.11 °C and 37.78°C), and the indoor temperature is between
70°F and 80°F (21.11°C and 26.67°C). Follow the procedure

below:
Unit is factory charged for 15ft (4.57 m) of lineset. Adjust charge

by adding or removing 0.6 oz/ft of 3/8 liquid line above or below
15ft (4.57 m) respectively.

For standard refrigerant line lengths (80 ft/24.38 m or less), allow
system to operate in cooling mode at least 15 minutes. When

operating with the Observer Wall Control in communicating mode,
make sure that indoor airflow is set to the final operating selection

(Eft 325, Elf 350, Comfort, Maximum) during charging. If
conditions are favorable, check system charge by subcooling
method. If any adjustment is necessary, adjust charge slowly and

allow system to operate for 15 minutes to stabilize before
declaring a properly charged system.

If the indoor temperature is above 80°F (26.67°C), and the
outdoor temperature is in the favorable range, adjust system

charge by weight based on line length and allow the indoor
temperature to drop to 80°F (26.67°C) before attempting to check

system charge by subcooling method as described above.
If the indoor temperature is below 70°F (21.11 °C), or the outdoor

temperature is not in the favorable range, adjust charge for line
set length above or below 15ft (4.57 m) only. Charge level should
then be appropriate for the system to achieve rated capacity. The

charge level could then be checked at another time when the
both indoor and outdoor temperatures are in a more favorable

range.
NOTE: The Observer Wall Control has a staging timer, to override

the staging timer for charging in high-stage create at least a 5
degree difference between room and set point temperatures and

hold the "Cool To" button for 10 seconds on the thermostat home
screen.

NOTE: If line length is beyond 80 ft (24.38 m) or greater than 20
ft (6.10 m) vertical separation, See Long Line Applications Guideline

for special charging requirements.
SYSTEM FUNCTIONS AND SEQUENCE OF

OPERATION
The *CA9 and *CA7 models utilize either an Observer

Communicating Wall Control or a 2-stage cooling thermostat. With
a call for first stage cooling, the outdoor fan and low-stage

compressor are energized. If low-stage cannot satisfy cooling
demand, high-stage is energized by the second stage of the

indoor thermostat. After second stage is satisfied, the unit returns
to low-stage operation until first stage is satisfied or until second

stage is required again. When both first stage and second stage
cooling are satisfied, the compressor will shut off. When a 2-stage

unit is operating at low-stage, system vapor (suction) pressure will
be higher than a standard single-stage system or high-stage
operation. When the outdoor ambient is more than 100°F

(37.8°C), the outdoor fan will continue to run for one minute after
compressor shuts off, this reduces pressure differential for easier

starting in the next cycle.
Communication and Status Function Lights

Green communications (COMM) Light (Only with
Observer Communicating Wall Control)

A green LED (COMM light) on the outdoor board indicates
successful communication with the other system products. The

green LED will remain OFF until communications is established.
Once a valid command is received, the green LED will turn ON

continuously. If no communication is received within 2 minutes,
the LED will be turned OFF until the next valid communication.

Amber Status Light (STATUS)

An amber colored STATUS light is used to display the operation
mode and fault codes as specified in the troubleshooting section.

See Table 6 for codes and definitions.

NOTE: Only one code will be displayed on the outdoor unit control

board (the most recent, with the highest priority).

Utility Interface with Non-Communicating Thermostat

The utility curtailment relay should be wired in the Y2 thermostat

lead. This allows a power utility device to interrupt high stage

compressor operation during peak load periods. If the utility

requires control of low stage compressor operation a second

utility curtailment relay should be wired in the Y1 lead.

NOTE: Utility curtailment is not available when operating in
communicating mode. To apply utility curtailment with the Observer
Wall Control you must use a daughter board kit to convert the control
signals to standard thermostat signals.

Compressor Operation
The basic scroll design has been modified with the addition of an

internal unloading mechanism that opens a by-pass port in the
first compression pocket, effectively reducing the displacement of

the scroll. The opening and closing of the by-pass port is
controlled by an internal electrically operated solenoid. The

modulated scroll uses a single step of unloading to go from full
capacity to approximately 67% capacity. A single speed, high

efficiency motor continues to run while the scroll modulates
between the two capacity steps. Modulation is achieved by

venting a portion of the gas in the first suction pocket back to the

low side of the compressor, thereby reducing the effective
displacement of the compressor. Full capacity is achieved by

blocking these vents, thus increasing the displacement to 100%.
A DC solenoid in the compressor controlled by a rectified 24 volt

AC signal in the external solenoid plug moves the slider ring that
covers and uncovers these vents. The vent covers are arranged

in such a manner that the compressor operates at approximately
67% capacity when the solenoid is not energized and 100%

capacity when the solenoid is energized. The loading and
unloading of the two step scroll is done "on the fly" without
shutting off the motor between steps.

NOTE: 67% compressor capacity translates to approximately 75%
cooling capacity at the indoor coil. The compressor will always start
unloaded and stay unloaded for five seconds even when the
thermostat is calling for high-stage capacity.

Crankcase Heater Operation
The crankcase heater is de-energized when the compressor is

running. The crankcase heater is energized when the
compressor is off and the ambient is less than 42 ° F. When the

ambient temperature is between 65° F and 42 ° F the crankcase

heater is energized 30 minutes after the compressor is turned off.
When the ambient is above 65 ° F the crankcase heater remains

de-energized after the compressor is turned off.

Outdoor Fan Motor Operation

The outdoor unit control energizes the outdoor fan any time the
compressor is operating. The outdoor fan remains energized if a

pressure switch or compressor overload should open. Outdoor
fan motor will continue to operate for one minute after the

compressor shuts off when the outdoor ambient is greater than or
equal to 100°F (37.8°C) to allow for easier starting during next

cooling cycle.

On *CA7 models - The outdoor fan motor is a PSC type. A fan
relay on the control board turns the fan off and on by opening and

closing a high voltage circuit to the motor. It does not change
speeds between low and high stage operation.

On *CA9 models - The outdoor fan is an ECM type. The motor
control is continuously powered with high voltage. The motor

speed is determined by electrical pulses provided by the PWM
outputs on the control board. The ECM motor RPM adjusts to

outdoor conditions as described in Table 3. The PWM output can
be measured between the PWM1 and PWM2 terminals on the

circuit board with a volt meter set to DC volts.

Table 3 - Outdoor Fan Motor PWM

Outdoor Temp (DC volts, Tolerance +/- 2%)

Model Low-Stage High Stage Low & High Stage

Size OAT _104OF/40oc OAT_ 104OF/40oc OAT> 104OF/40oc

*CA924 9.57 10.88 11.90
*CA936 9.06 10.23 11.90
*CA948 9.91 11.04 11.90
*CA960 10.83 11.70 11.90

Time Delays
The unit time delays include:

• Five minute time delay to start cooling operation when
there is a call from the thermostat or user interface. To

bypass this feature hold the "Cool To" or "Heat To" button
on the Observer Wall Control for 10 seconds.

• Five minute compressor re-cycle delay on return from a

brown-out condition.

• Two minute time delay to return to standby operation from

last valid communication (Observer Communicating Wall
Control only).

• One minute time delay of outdoor fan at termination of

cooling mode when outdoor ambient is greater than or
equal to 100°F (37.8°C).

• There is no delay between staging from low to high and
from high to low capacity. The compressor will change from

low to high and from high to low capacity "on the fly" to meet

the demand.

TROUBLESHOOTING
If the compressor fails to operate with a cooling call, Table 4 can

be used to verify if there is any damage to the compressor
windings causing system malfunction.

Table 4 - Winding Resistance

Winding Resistance At 70°F +/- 20°F

(21.11°C +/- 11.11°C)

Winding 24 36 48 60

Start

(S-C) 1.64 1.52 1.86 1.63

Run

(R-C) 1.30 0.88 0.52 0.39

Systems Communication Failure

If communication with the Observer Communicating Wall Control
will flash the appropriate fault code. (See Table 6) Check the

wiring to the wall control, indoor and outdoor units.

Model Plug

Each control board contains a model plug. The correct model
plug must be installed for or the system to operate properly (see

Table 5).

8 Specifications subject to change without notice. 421 01 1702 04

Table 5 - Model Plug

Pin Resistance

Model

Number

*CA724
*CA736

*CA748
*CA760

*CA924
*CA936

*CA948
*CA960

Model Plug

Number

HK70EZ040
HK70EZ042

HK70EZ044
HK70EZ046

HK70EZ009
HK70EZ011

HK70EZ013
HK70EZ015

The model plug is used to identify the type and size of unit to the
control.

On new units, the model and serial numbers are input into the

board's memory at the factory. Ifa model plug is lost or missing at
initial installation, the unit wilt operate according to the information

input at the factory and the appropriate error code wilt flash

temporarily.
A FAST® Parts replacement board contains no model and serial

information. If the factory control board fails, the model plug must
be transferred from the original board to the replacement board

for the unit to operate.

NOTE: The model plug takes priority over factory model information
input at the factory. If the model plug is removed after initial power
up, the unit will operate according to the last valid model plug
installed, and flash the appropriate fault code temporarily.

Pressure Switch Protection

The outdoor unit is equipped with high and low pressure
switches.

If the control senses the opening of a high or low pressure switch,
it will respond as follows:

1. De-energize the appropriate compressor contactor.

2. Keep the outdoor fan operating for 15 minutes.

3. Display the appropriate fault code (see Table 6).

4. After a 15 minute delay, if there is still a call for cooling and
the LPS or HPS is reset, the appropriate compressor

contactor is energized.

5. If LPS or HPS has not closed after a 15 minute delay, the
outdoor fan is turned off. If the open switch closes anytime

after the 15 minute delay, then resume operation with a call
for cooling.

6. If LPS or HPS trips 3 consecutive cycles, the unit operation
is locked out for 4 hours.

7. In the event of a high pressure switch trip or high pressure
lockout, check the refrigerant charge outdoor fan operation

and outdoor coil for airflow restrictions.

8. In the event of a low pressure switch trip or low pressure
lockout, check the refrigerant charge and indoor airflow.

Control Fault

If the outdoor unit control board has failed, the control will flash

the appropriate fault code. (See Table 6) The control board
should be replaced.

Brown Out Protection
If the line voltage is less than 187v for at least 4 seconds, the

appropriate compressor contactor and fan relay are de-energized.
Compressor and fan operation are not allowed until voltage is a

minimum of 190v. The control will flash the appropriate fault code

(see Table 6)
230 V Brown Out Protection Defeated:

The brownout feature can be defeated if needed for severe noisy

power conditions. This defeat should always be a last resort to

solving the problem. Defeat can be initiated through the forced

421 01 1702 04

(kOhms)

Pin 1-4 Pin 2-3

18 75
18 120

18 180
18 270

5.1 91

5.1 150

5.1 220

5.1 360

Specifications subject to change without notice. 9

defrost pins as follows:
The brownout toggle is accomplished by shorting the defrost pins

from power up with the OAT and OCT sensor connector removed.
After 3 seconds, the status of the force defrost short and the

OAT/OCT as open will be checked. If correct, then the brownout
wilt be toggled.

• Status code 6 shows the brownout is disabled.

• Status code 5 shows the brownout is active.

After the brownout defeat is set, power down and reinstall the
OAT/OCT sensor and remove the short from the forced defrost

pins. As long as the short on the forced defrost remains, the OAT
and OCT faults will not be cleared. The code will continue to be

flashed.
The control is shipped with the brownout active. The change in

status is remembered until toggled to a new status. A power
down/power up sequence will not reset the status. It may be

necessary to do the toggle twice to cycle to the desired state of
the defeat.

230V Line (Power Disconnect) Detection

If there is no 230v at the compressor contactor(s) when the indoor
unit is powered and cooling demand exists, the appropriate error

code is displayed (see Table 6). Verify that the disconnect is
closed and 230v wiring is connected to the unit.

Compressor Voltage Sensing

The control board input terminals labeled VS and L2 (see Fig. 10)
are used to detect compressor voltage status, and alert the user
of potential problems. The control continuously monitors the high

voltage on the run capacitor of the compressor motor. Voltage
should be present any time the compressor contactor is

energized, and voltage should not be present when the contactor
is de-energized.

Contactor Shorted Detection

If there is compressor voltage sensed when there is no demand
for compressor operation, the contactor may be stuck closed or

there is a wiring error. The control will flash the appropriate fault
code.

Compressor Thermal Cutout

If the control senses the compressor voltage after start-up, and is
then absent for 10 consecutive seconds while cooling demand

exists, the thermal protector is open. The control de-energizes
the compressor contactor for 15 minutes, but continues to operate

the outdoor fan.
The control Status LED will flash the appropriate code shown in

Table 6. After 15 minutes, with a call for low or high stage cooling,
the compressor contactor is energized. If the thermal protector

has not reset, the outdoor fan is turned off. If the call for cooling
continues, the control will energize the compressor contactor

every 15 minutes. If the thermal protector closes, (at the next 15
minute interval check), the unit will resume operation. If the

thermal cutout trips for three consecutive cycles, then unit
operation is locked out for 4 hours and the appropriate fault code

is displayed.

No 230V at Compressor

If the compressor voltage is not sensed when the compressor
should be starting, the appropriate contactor may be stuck open

or there is a wiring error. The control will flash the appropriate fault
code. Check the contactor and control box wiring.

Troubleshooting units for proper switching
between low & high stages

Check the suction pressures at the service valves. Suction
pressure should be reduced by 3-10% when switching from low

to high capacity.

NOTE: The liquid pressures are very similar between low and high
stage operation so liquid pressure should not be used for
troubleshooting.

Compressor current should increase 20-45% when switching
from low to high stage. The compressor solenoid, when

energized in high stage, should measure 24vac across pin

numbers PL5-2 HI and PL5-5 C. When the compressor is
operating in low stage the 24v DC compressor solenoid coil is

de-energized. When the compressor is operating in high stage,
the 24v DC solenoid coil is energized. The solenoid plug harness

that is connected to the compressor has an internal rectifier that
converts the 24v AC signal to 24v DC.

NOTE: DO NOT INSTALL A PLUG WITHOUT AN
INTERNAL RECTIFIER,

Unloader Test Procedure

The unloader is the compressor internal mechanism, controlled
by the DC solenoid, that modulates between high and low stage.

If it is suspected that the unloader is not working, the following
methods may be used to verify operation.

1. Operate the system and measure compressor amperage.
Cycle the unloader on and off at 30 second plus intervals at

the Wall Control (from low to high stage and back to low
stage). Wait 5 seconds after staging to high before taking a

reading. The compressor amperage should go up or down

at least 20 percent.

2. If step one does not give the expected results, remove the
solenoid plug from the compressor and, with the unit

running and the Wall Control (or Thermostat) calling for
high stage, test the voltage output at the plug with a DC

voltmeter. The reading should be 24 volts DC.

3. If the correct DC voltage is at the control circuit molded

plug, measure the compressor unloader coil resistance.

The resistance should be approximately 330 or 1640 ohms

depending on unloader coil supplier. If the coil resistance is
infinite or is grounded, the compressor must be replaced.

MAJOR COMPONENTS

2-Stage Control

The 2-stage control board controls the following functions:

-- Compressor high and low stage operation

-- Outdoor fan motor operation

-- Compressor external protection

-- Pressure switch monitoring

-- Time delays

Field Connections

On models with non-communicating (Thermostat other than
Observer Wall Control) system, the 2-stage control receives

24vac low-voltage control system inputs through the Y1, and Y2

connections located at the bottom of the control board (see Fig.

10). The OD units can be controlled using a standard 2-stage
thermostat or Observer Wall Control.

2-Stage Compressor

The 2-stage compressor contains motor windings that provide
2-pole (3500 RPM) operation. Refer to Table 4 for correct winding
resistance.

Compressor Internal Relief

The compressor is protected by an internal pressure relief (IPR)
which relieves discharge gas into compressor shell when

differential between suction and discharge pressures exceeds
550 - 625 psig The compressor is also protected by an internal

overload attached to motor windings.

Compressor Control Contactor

The contactor has a 24 volt coil. The electronic control board
controls the operation of the appropriate contactor.

TEMPERATURE THERMISTORS

Thermistors are electronic devices which sense temperature. As
the temperature increases, the resistance decreases. Thermistors

are used to sense outdoor ambient (OAT) and coil temperature
(OCT). Refer to Fig. 9 for resistance values versus temperature. If
the outdoor ambient or coil thermistor should fail, the control will

flash the appropriate fault code (see Table 6.)

IMPORTANT: Outdoor air thermistor and coil thermistor are

factory mounted in the final locations. Check to insure thermistors
are mounted properly per Fig.7 and Fig.8.

Thermistor Sensor Comparison

The control continuously monitors and compares the outdoor air
temperature sensor and outdoor coil temperature sensor to

ensure proper operating conditions. The comparison is:

-- If the outdoor air sensor indicates 10°F (5.56°C) warmer than
the coil sensor (or) the outdoor air sensor indicates 20°F (11.1 °C)
cooler than the coil sensor, the sensors are out of range.

-- If the sensors are out of range, the control will flash the
appropriate fault code as shown in Table 6.

-- The thermistor comparison is not performed during low
ambient cooling or defrost operation.

Failed Thermistor Default Operation

Factory defaults have been provided in the event of failure of
outdoor air thermistor and/or coil thermistor. If the OAT sensor

should fail, low ambient cooling will not be allowed and the one
minute outdoor fan-off delay will not occur. If the OCT sensor

should fail, low ambient cooling will not be allowed.

OAT Thermistor must be locked in place with
spherical nib end facing towards the front of the

control box.

10 Specificationssubjectto change without notice. 421 01 1702 04

Table 6 - Status Codes

OPERATION FAULT Possible Cause and Action

Standby- no call for unit operation None On solid, no flash Normal operation
Low Stage Cool/Heat Operation None 1, pause Normal operation
High Stage Cool/Heat Operation None 2, Pause Normal operation

Brown out protection is Disabled None 5, pause User mode selection, see instructions for more detail
Brown out protection is Active None 6, Pause User mode selection, see instructions for more detail

System Communications 16 Communication with Observer Wall Control lost. Check wiring to

Failure Observer Wall Control, indoor and outdoor units

Invalid Model Plug 25

High Pressure 31" High pressure switch trip. Check refrigerant charge, outdoor fan

Switch Open operation and coils for airflow restrictions.

Low Pressure

Switch or Discharge Temp 32* refrigerant charge and indoor air flow

Switch Open

Control Fault 45 replaced.

Brown Out 46 Line Voltage <187v for at least 4 seconds. Compressor and fan

(230 v) operation not allowed until voltage > 190v. Verify line voltage.

No 230v at Unit 47 cooling/heating demand exists. Verify the disconnect is closed and

Outdoor Air Temp Sensor 53 Outdoor air sensor not reading or out of range. Ohm out sensor and

Outdoor Coil Sensor Fault 55 Coil sensor not reading or out of range. Ohm out sensor and check

*Sequence: Compressor contactor is de-energized and outdoor fan is energized for up to 15 minutes. If demand still exists, control will energize compressor.

Fault check wiring

Thermistors out 56 Improper relationship between coil sensor and outdoor air sensor.

of range Ohm out sensors and check wiring.

Low Stage Compressor operation detected then disappears while low stage

Thermal Cutout 71" demand exists. Possible causes are internal compressor overload trip

High Stage Compressor operation detected then disappears while high stage

Thermal Cutout 72* demand exists. Possible causes are internal compressor overload trip

Contactor Shorted 73 operation exists. Contactor may be stuck closed or there is a wiring

No 230V at Compressor voltage not sensed when compressor should be starting.

Compressor wiring error.

Low Stage Thermal 82 Thermal cutout occurs in three consecutive low/high cycles. Low stage

Lockout locked at for 4 hours or until 24v power recycled.

High Stage Thermal 82 Thermal cutout occurs in three consecutive low/high cycles. High

Lockout stage locked out for 4 hours or until 24v power recycled.

Low Pressure Lockout 83

High Pressure 84 High pressure switch trip has occurred during 3 consecutive cycles.

Lockout Unit operation locked out for 4 hours or until 24v power recycled.

AMBER LED

FLASH CODE

Control does not detect a model plug or detects and invalid model

plug. Unit will not operate without correct model plug.

Low pressure switch or discharge temperature switch trip. Check

Outdoor unit control board has failed. Control board needs to be

There is not 230v at the contactor when indoor unit is powered and

230v wiring is connected to the unit.

wiring

or start relay and capacitor held in circuit too long (if installed)

or start relay and capacitor held in circuit too long (if installed)

Compressor voltage sensed when no demand for compressor

error.

74 Disconnect may be open or contactor may be stuck open or there is a

Low pressure switch trip has occurred during 3 consecutive cycles.

Unit operation locked out for 4 hours or until 24v power recycled.

421 01 1702 04 specificationssubjectto change without notice. 11

Figure 9 J

Resistance vs Temperature Chart

THERMISTOR CURVE

90
804

(-17.77) (-6.67) (4.44) (15.56) (26.67) (37.78) (48.89)

4 t I t I

O 20 40 60 80 100 120

Figure 10 J Two-Stage Control Board

] T F F

TEMPERATURE °F (°C)

0,250

0._0

0,0&2 +1- .0075

__J

ALL DIMENSIONS ARE IN INCHES

12 specificationssubjectto change without notice. 421 01 17'02 04

Figure 11

ObserverCommunicatingWallControlFour-WireConnectionWiringDiagrams

(See Thermostat Installation Instructions for specific unit combinations)

Wall Control Furnace/Fan Coil Outdoor

Green

Yellow

White

Red

Room Sensor Humidifier

-- Connection

.Optional Remote .._

Variable Speed

_ Green _

Yellow_,q

HUM

COM

-- 24V FACTORY WIRING

..... 24V FIELD WIRING

FIELD SPLICE CONNECTION

Variable Speed Furnace with

Figure 12 Two-Stage Air Conditioning

Indoor Control Fan Coil

Heat Stage 2
Heat Stage 11_'

Cool Stage 1 f'_"

Cool Stage 2 I--_-_.

Fan

24 VAC Hot

J FVM Fan Coil Wiring With

Two-Stage Air Conditioner

I

Remove J2 Jumper
For Heat Staging

I Y/Y2 II

BDD

BDD

-J-_l
.4--_1

Figure 13 Two-Stage Air Conditioner

ICP Thermostat

LEGEND

Variable Speed

Furnace

. __1-"_

__1--_-" _ __

--E3

--12D

Two-Stage
Heat Pump

Dehumidify fD"_'_.

24 VAC Comm

Humidify

RVS Heatingr__

Outdoor t( _

BDD

BDD

__ Humidifier

__ Outdoor

,-I, H i i

/ (24VAC) /

/ Sensor I J

D HUM

OUTDOOR

SENSOR

421 01 1702 04 specificationssubjectto change without notice. 13

Figure 14 Observer Communicating Wall Control

Non-Communicating Indoor Unit with

Wall

Control

NAXA00101DB

Green

Red ,_

White "C_

Yellow ,_

Communicating

Outdoor

"C_'

----A--

I- q GD

____A__r-

Non-Communicating

Indoor

Note: This installation requires the daugh-
ter board accessory, NAXA00101DB. _o

Note: This installation does not allow for OAT
communicating feature functionality.

Final Checks

IMPORTANT: Before leaving job, be sure to do the following:

1. Ensure that all wiring is routed away from tubing and sheet
metal edges to prevent rub-- through or wire pinching.

2. Ensure that all wiring and tubing is secure in unit before
adding panels and covers. Securely fasten all panels and

covers.

3. Tighten service valve stem caps to 1/12--turn past finger
tight.

4. Leave Owner's Manual with owner. Explain system

operation and periodic maintenance requirements outlined
in manual.

L'O

OAT

Sensor

CARE AND MAINTENANCE

For continuing high performance and to maintain warranty
coverage, periodic maintenance must be performed on this

equipment. Frequency of maintenance may vary depending
upon geographic areas, such as coastal applications. See

Owner's Manual for information.

14 specificationssubjectto change without notice. 421 01 1702 04

R-410A QUICK REFERENCE GUIDE

• R-410A refrigerant operates at 50% - 70% higher pressures than R-22. Be sure that servicing equipment and
replacement components are designed to operate with R-410A.

• R-410A refrigerant cylinders are rose colored.

• Recovery cylinder service pressure rating must be 400 psig, DOT 4BA400 or DOT BW400.

• R-410A systems should be charged with liquid refrigerant. Use a commercial type metering device in the
manifold hose when charging into suction line with compressor operating.

° Manifold sets should be 750 psig high-side and 200 psig low-side with 520 psig low-side retard.

° Use hoses with 750 psig service pressure rating.

° Leak detectors should be designed to detect HFC refrigerant.

° R-410A, as with other HFC refrigerants, is only compatible with POE oils.

° Vacuum pumps will not remove moisture from oil.

° Do not use liquid line filter-driers with rated working pressures less than 600 psig.

° Do not install a suction line filter-drier in liquid line.

° POE oils absorb moisture rapidly. Do not expose oil to atmosphere.

° POE oils may cause damage to certain plastics and roofing materials.

° Wrap all filter-driers and service valves with wet cloth when brazing.

° A liquid line filter-drier is required on every unit.

° Do not use with an R-22 TXV.

° If indoor unit is equipped with an R-22 TXV, it must be changed to an R-410A TXV.

° Never open system to atmosphere while it is under a vacuum.

° When system must be opened for service, break vacuum with dry nitrogen and replace all filter-driers. Evacuate
to 500 microns before recharging.

° Do not vent R-410A into the atmosphere.

° Do not use capillary tube indoor coils.

° Observe all WARNINGS, CAUTIONS, NOTES, and bold text.

421 01 1702 04 Specificationssubjectto change without notice. 15

16

Specifications subject to change without notice.
Copyright 2015 International Comfort Products

Lewisburg, TN 37091 USA

421 01 1702 04