ICP C4A318GKA100, C4A318GKD100, C4A324GKD100, C4A330GKA100, C4A330GKD100 Installation Guide

INSTALLATION INSTRUCTIONS

R- 410A Split System Air Conditioner

C4A3, H4A3, T4A3,
CXA6, HXA6, TXA6

These instructions must be read and understood completely before attempting installation.

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 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.

Recognize safety information. This is the safety- alert

!

!

symbol
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. W ARNING 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.

ELECTRICAL SHOCK HAZARD

Failure to follow this warning could result in personal
injury 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
warning label.

When you see this symbol on the unit and in

!

WARNING

!

WARNING

EXPLOSION HAZARD

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

Never use air or gases containing
oxygen for leak testing or
operating refrigerant compressors.
Pressurized mixtures of air or
gases containing oxygen can lead
to an explosion.

INSPECT NEW UNIT

After uncrating the unit, inspect it thoroughly for any
obvious or hidden damage. If damage is found, notify the
transportation company immediately and file a
concealed damage claim.

!

PROPERTY DAMAGE HAZARD

Failure to follow this caution mayresult in proper­ty damage

R- 410A systems operate at higher pressures than
R- 22 systems. When working with R- 410A sys­tems, use only service equipment and replace­ment components specifically rated or approved
for R- 410A service.

CUT HAZARD

Failure to follow this c aution 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.

CAUTION

!

CAUTION

LOCATION

Check local codes for regulations concerning zoning,
noise, platforms, and other issues.

Locate unit away from fresh air intakes, vents, or
bedroom windows. Noise may carry into the openings
and disturb people inside.

421 01 5103 05 9/22/17

INSTALLA TION INSTRUCTIONS R- 410A Split System Air Conditioner

Locate unit in a well drained area, or support unit high
enough so that water runoff will not enter the unit.

Locate unit away from areas where heat, lint, or exhaust
fumes will be discharged onto unit (as from dryer vents).

Locate unit away from recessed or confined areas where
recirculation of discharge air may occur (refer to
CLEARANCES section of this document).

Roof- top installation is acceptable providing the roof will
support the unit and provisions are made for water
drainage and noise/vibration dampening.

NOTE: Roof mounted units exposed to wind may require
wind baffles. Consult the manufacturer for additional
information.

CLEARANCES

When installing, allow sufficient space for airflow
clearance, wiring, refrigerant piping, and service. Allow
24 in. (610 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 or 18 in.
(457.2 mm) if no overhang within 12 ft. (3.66 m). Position
so water, snow, or ice from roof or eaves cannot fall
directly on unit.

Operating Ambient

The minimum outdoor operating ambient in cooling mode
without accessory is 55_F (12.78_C). The maximum outdoor
operating ambient in cooling mode is 125_F (51.7_C) for
non- 13 SEER models and 115_F (46.11_C) for 13 SEER
models.

UNIT SUPPORT

NOTE: Unit must be level + 2 degrees [a ⅜inch rise or fall

per foot of run (10 mm rise or fall per 305 mm of run)] or
compressor may not function properly.

or pad does not shift or settle and leave the unit partially
supported. Minimum pad dimensions are shown in
Figure 1.

If beams or an open platform are used for support, it is
recommended that the soil be treated or area be
graveled to reduce the growth of grasses and weeds.

To minimize vibration or noise transmission, it is
recommended that supports not be in contact with the
building structure. However, slabs on grade
constructions with an extended pad are normally
acceptable.

B. ROOF TOP INSTALLATION

This type of installation is not recommended on wood
frame structures where low noise levels are required.

Supporting structure or platform for the unit must be
level. If installation is on a flat roof, locate unit minimum 6
inches (152 mm) above roof level.

Place the unit over one or more load bearing walls. If
there are several units, mount them on platforms that are
self- supporting and span several load bearing walls.
These suggestions are to minimize noise and vibration
transmission through the structure. If the structure is a
home or apartment, avoid locating the unit over
bedrooms or study.

NOTE: When unit is to be installed on a bonded
guaranteed roof, a release must be obtained from the
building owner to free the installer from all liabilities.

C. FASTENING UNIT DOWN

If conditions or local codes require the unit be attached in
place, remove the knockouts in the base pan and install
tie down bolts through the holes (refer to Figure 1).

Contact local distributor for hurricane hold- down details
and the P .E. (Professional Engineer) certification, when
required.

!

CAUTION

A. GROUND LEVEL INSTALLATION

The unit must be level and supported above grade by
beams, platform, or a pad. Platform or pad can be of
open or solid construction but should be of permanent
materials such as concrete, bricks, blocks, steel, or
pressure- treated timbers approved for ground contact.
Soil conditions must be considered so that the platform

2 421 01 5103 05

PROPERTY DAMAGE HAZARD

Failure to follow this caution may result in
property damage.

Inadequate unit support may cause excessive vi­bration, noise, and/or stress on the refrigerant
lines, leading to refrigerant line failure.

INSTALLA TION INSTRUCTIONS R- 410A Split System Air Conditioner

Figure 1 Tie Down Knockouts

a” (10mm) dia. Tie Down Knockouts
In Base Pan (2 places)

A

Base Pan

Width x

Depth

23 x 23

(584 x 584)

25- 11/16 x

25- 11/16

(652 x 652)

31- 1/8 x

31- 1/8

(791 x 791)
34- 15/16 x

34- 15/16

(887 x 887)

Base Pan Width

Inches (mm)

Tie Down

Knockouts

A B C

7- 3/4

(197)

9- 1/16

(230)

9- 1/16

(230)

9- 1/16

(230)

4- 7/16

(113)18(457)

4- 7/16

(113)

6- 1/2

(165)

6- 1/2

(165)

21- 1/4

(540)

24- 5/8

(625)

28- 7/16

(722)

View From Top

Base

Pan

Depth

C

B

Minimum

Mounting Pad

Dimensions

23 x 23

(584 x 584)

26 x 26

(660 x 660)

31- 1/2 x

31- 1/2

(800 x 800)

35 x 35

(889 x 889)

REFRIGERATION SYSTEM

A. COMPONENT MATCHES

Check to see that the proper system components are in
place, especially the indoor coil.

R- 410A outdoor units can only be used with R- 410A
specific indoor coils. If there is a refrigerant mis- match,
consult the indoor coil manufacturer to determine if a
refrigerant conversion kit is available for the indoor coil.

This outdoor unit is designed for use only with indoor
coils that utilize a TXV refrigerant metering device or
Piston with Teflon ring metering device. If any other type
of metering device is installed on the indoor coil, consult
the indoor coil manufacturer to determine if a TXV
conversion kit is available.

Installing with TXV

When installing a TXV on an indoor coil, follow the
instructions provided with the new TXV.

A typical TXV installation is shown in Figure 2.

Figure 2

Typical TXV Installation

INDOOR

COIL

EQUALIZER
TUBE

SENSING
BULB

SUCTION
TUBE

LIQUID
TUBE

TXV

10 O’clock

3/4

2 O’clock

SENSING BULB

STRAP

SUCTION TUBE

IN. OD & SMALLER

Installing with Indoor Piston - cooling operation.

Check piston size shipped with indoor unit to see if it
matches required indoor piston size. If it does not
match, replace indoor piston with the correct piston size.

NOTE: Correct pistons are shipped with select outdoor
units in the accessory bag and are only for use in certain
qualified and approved fancoils, i.e. FEM4P. (See
Product Specifications for list of approved fancoils that
use accessory piston.)

The piston included with the FMA4P* and FM(C,U)4P*
fancoils are unique to those products and cannot be
replaced with the piston shipped with the outdoor unit.
Refer to the AHRI Directory to check if your combination
can use a piston or requires an accessory TXV.

SeeFigure3.

When changing indoor piston, use a back- up wrench.
Hand tighten hex nut, then tighten with wrench 1/2 turn.
Do not exceed 30 ft- lbs.The indoor piston contains a
Teflon ring (or seal) which is used to seat against the
inside of distributor body, and must be installed properly
to ensure proper seating in the direction for cooling
operation.

421 01 5103 05 3

Specifications subject to change without notice.

INSTALLA TION INSTRUCTIONS R- 410A Split System Air Conditioner

Figure 3 Indoor (cooling) Piston

BRASS

HEX NUT

B. REFRIGERANT LINE SETS

The refrigerant line set must be properly sized to assure
maximum efficiency and proper oil circulation.

Refer to Product Specifications and Long Line
Applications Guideline for line set sizing.

NOTE: Total line set length must not exceed 200 feet (61

m).

A crankcase heater must be used when the refrigerant
line length exceeds 80 feet (24.4 m).

If outdoor unit is more than 10 feet (3 m) higher than the
indoor coil, refer to the Long Line Applications Guideline
for instructions.

When the outdoor unit is higher than the indoor coil, the
vertical separation must not exceed 100 feet (30 m).

When the outdoor unit is lower than the indoor coil, the
vertical separation must not exceed 50 feet (15.2 m).

If it is necessary to add refrigerant line in the field, use
dehydrated or dry, sealed, deoxidized, copper
refrigeration tubing. Do not use copper water pipe.

Do not remove rubber plugs or caps from copper tubing
until connections are ready to be made.

TEFLON SEAL

PISTON
RETAINER

STRAINER

TEFLON RING

PISTON

FLOW IN
COOLING

DISTRIBUTOR

BRASS
HEX BODY

L10S017

Be extra careful when bending refrigeration tubing.
Tubing can “kink” easily, and if this occurs, the entire
length of tubing must be replaced.

!

PERSONAL INJURY HAZARD

Failure to relieve system pressure could result in
personal injury and/or death.

Relieve pressure and recover all refrigerant be­fore servicing existing equipment, and before fi­nal unit disposal. Use all service ports and open
all flow- control devices, including solenoid
valves.

C. ROUTING AND SUSPENDING REFRIGERANT

LINES

Run refrigerant lines as straight and direct as possible,
avoiding unnecessary bends and turns. Always insulate
the entire suction line. Both lines should be insulated
when routed through an attic or when routed through an
underground raceway.

When routing refrigerant lines through a foundation or wall,
do not allow refrigerant lines to come in direct contact with
the building structure. Make openings large enough so that
lines can be wrapped with extra insulation. Fill all gaps with
RTV caulk. This will prevent noise transmission between
the tubing and the foundation or wall.

Along floor or ceiling joists, suspend refrigerant lines so
that they do not contact the building structure, water
pipes, or ductwork. Use insulated or suspension type
hangers. Metal straps must be at least 1” (25 mm) wide to
avoid cutting into the tube insulation. Keep the liquid and
suction lines separate. Refer to Figure 4.

!

UNIT OPERATION HAZARD

Failure to follow this caution may result in im­proper product operation.

Do not leave system open to atmosphere any lon­ger than absolutely required for installation. Inter­nal system components - especially refrigerant
oils - are extremely susceptible to moisture con­tamination. Keep ends of tubing sealed during in­stallation until the last possible moment.

WARNING

CAUTION

4 421 01 5103 05

INSTALLA TION INSTRUCTIONS R- 410A Split System Air Conditioner

Figure 4 Routing and Suspending Refrigerant Lines

OUTDOOR WALL INDOOR WALL

!

CAULK

INSULATION

THROUGH THE WALL SUSPENSION

CAUTION

LIQUID TUBE

SUCTION TUBE

UNIT OPERATION HAZARD

Failure to follow this caution may result in im­proper product operation.

Do not bury more than 36” (1m) of line set under­ground. Refrigerant may migrate to cooler buried
section during extended periods of unit shut­down, causing refrigerant slugging and possible
compressor damage at start- up.
If ANY section of the line set is buried under­ground, provide a minimum 6” (152mm) vertical
rise at the service valve.

HANGER STRAP

(AROUND SUCTION

TUBE ONLY)

1” (25mm)

MIN

Figure 5

JOIST

INSULATION

SUCTION TUBE

LIQUID TUBE

Liquid Line Filter- Drier

Installed at Indoor Coil

D. OUTDOOR UNIT HIGHER THAN INDOOR UNIT

Proper oil return to the compressor should be maintained
with suction gas velocity. If velocities drop below 1500
fpm (feet per minute), oil return will be decreased. To
maintain suction gas velocity, do not upsize vertical
suction risers.

E. LIQUID LINE FILTER- DRIER

Outdoor units are shipped with an appropriate filter- drier
for installation in the liquid line. Leave the plugs in the
tube ends until the filter- drier is installed. The optimal
location for the filter- drier is close to the indoor coil.
Install the filter- drier with the arrow pointing towards the
indoor coil. Refer to Figure 5.

Filter- Drier
(arrow points towards indoor coil)

38- 11- 84

F. SERVICE VALVES

Service valves are closed and tube stubs are plugged
from the factory. Outdoor units are shipped with a
refrigerant charge sealed in the unit. Leave the service
valves closed until all other refrigerant system work is
complete or the charge will be lost. Leave the plugs in
place until line set tubing is ready to be inserted.

Service valve bodies are brass and tube stubs are
copper.

421 01 5103 05 5

Specifications subject to change without notice.

INSTALLA TION INSTRUCTIONS R- 410A Split System Air Conditioner

Figure 6 Service Valve

VALVE CORE

SERVICE VALVE

G. BRAZING CONNECTIONS
NOTE: Remove valve core from schrader port on both

Service Valves BEFORE brazing. This helps prevent
overheating and damage to valve seals (refer to Figure 6).
Replace valve core when brazing is completed.

!

WARNING

FIRE HAZARD

Failure to remove refrigerant and oil charge be­fore brazing could result in personal injury, death,
and/or property damage.

Refrigerant and oil mixture could ignite and burn
as it escapes and contacts brazing torch. Make
sure the refrigerant charge is properly removed
from both the high and low sides ofthe system be­fore brazing any component or lines.

Clean line set tube ends with emery cloth or steel brush.
Remove any grit or debris.

Insert line set tube ends into service valve tube stubs.
Apply heat absorbing paste or heat sink product between

service valve and joint. Wrap service valves with a heat
sinking material such as a wet cloth.

Braze joints using a Sil- Fos or Phos- copper alloy.

!

CAUTION

!

CAUTION

PRODUCT DAMAGE HAZARD

Failure to follow this caution may result in product dam­age.

Never use the outdoor unit compressor as a vacu­um pump. Doing so may damage the compressor .

Line set and indoor coil should be evacuated using the
recommended deep vacuum method of 500 microns. If
deep vacuum equipment is not available, the alternate
triple evacuation method may be used by following the
specified procedure.

If vacuum must be interrupted during the evacuation
procedure, always break vacuum with dry nitrogen.

Deep Vacuum Method

The deep vacuum method requires a vacuum pump
capable of pulling a vacuum to 500 microns and a
vacuum gauge capable of accurately measuring this
vacuum level. The deep vacuum method is the most
positive way of assuring a system is free of air and water.

Watch the vacuum gauge as the system is pulling down.
The response of the gauge is an indicator of the condition
of the syst em (refer to Figure 7).

With no leaks in the system, allow the vacuum pump to
run for 30 minutes minimum at the deep vacuum level.

Figure 7

5000

4500

4000

3500

3000

2500

2000

MICRONS

1500

1000

500

Deep Vacuum Gauge Response

and System Conditions

LEAK IN
SYSTEM

VACUUM TIGHT
TOO WET

TIGHT
DRY SYSTEM

PRODUCT DAMAGE HAZARD

Failure to follow this caution may result in product dam­age.

Braze with Sil- Fos or Phos - copper alloy on cop­per- to- copper joints and wrap a wet cloth around
rear of fitting to prevent damage to TXV.

H. EVACUATING LINE SET AND INDOOR COIL

The unit is shipped with a factory refrigerant charge. The
liquid line and suction line service valves have been closed
after final testing at the factory. Do not disturb these valves
until the line set and indoor coil have been evacuated and
leak checked, or the charge in the unit may be lost.

NOTE: Do not use any portion of the factory charge for
purging or leak testing. The factory charge is for filling the
system only after a complete evacuation and leak check
has been performed.

01

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 (71 1mm Hg). Refer to Figure 8 and proceed 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.

375

246

MINUTES

6 421 01 5103 05

INSTALLA TION INSTRUCTIONS R- 410A Split System Air Conditioner

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 8.

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.

Figure 8

BREAK VACUUM WITH DRY NITROGEN

BREAK VACUUM WITH DRY NITROGEN

CHECK FOR TIGHT, DRY SYSTEM

(IF IT HOLDS DEEP VACUUM)

I. OPENING SERVICE VALVES

Outdoor units are shipped with a refrigerant charge
sealed in the unit. Opening the service valves releases
this charge into the system.

NOTE: Open the Suction service valve first. If the Liquid
service valve is opened first, oil from the compressor
may be drawn into the indoor coil TXV, restricting
refrigerant flow and affecting operation of the system.

Remove Suction service valve cap and insert a hex
wrench into the valve stem. Hold the valve body steady
with an end- wrench and back out the stem by turning the
hex wrench counterclockwise. Turn the stem until it just
contacts the rolled lip of the valve body.

After the refrigerant charge has bled into the system,
open the Liquid service valve.

NOTE: These are not back- seating valves. It is not
necessary to force the stem tightly against the rolled lip.

The service valve cap is a primary seal for the valve and
must be properly tightened to prevent leaks. Make sure
cap is clean and apply refrigerant oil to threads and
sealing surface on inside of cap.

Tighten cap finger tight and then tighten additional 6 of a
turn (1 wrench flat) to properly seat the sealing surfaces.

421 01 5103 05 7

Triple Evacuation Sequence

EVACUATE

WAIT

EVACUATE

WAIT

EVACUATE

CHARGE SYSTEM

Specifications subject to change without notice.

J. GAUGE PORTS

Check for leaks at the schrader ports and tighten valve
cores if necessary. Install plastic caps finger tight.

ELECTRICAL WIRING
(*XA6 all sizes; *4A3 sizes 18, 36- 60
only)

NOTE: *4A3 sizes 24 and 30 on page 14.

!

ELECTRICAL SHOCK HAZARD

Failure to turn off the main (remote) electrical dis­connect device could result in personal injury or
death.

Before installing, modifying or servicing system,
turn OFF the main (remote) electrical disconnect
device. There may be more than one disconnect
device.

The supply voltage must be 208/230 volts (197 volt
minimum to 253 volts maximum) 60 Hz single phase.

Outdoor units are approved for use with copper
conductors only. Do not use aluminum wire.

Refer to unit rating plate for minimum circuit ampacity
and circuit protection requirements.

Grounding

Permanently ground unit in accordance with the National
Electrical Code and local codes or ordinances. Use a
copper conductor of the correct size from the grounding
lug in control box to a grounded connection in the service
panel or a properly driven and electrically grounded
ground rod.

Wiring Connections

Make all outdoor electrical supply (Line Voltage)
connections with raintight conduit and fittings. Most
codes require a disconnect switch outdoors within sight
of the unit. Consult local codes for special requirements.

Route electrical supply (Line Voltage) wiring through
knockout hole in bottom of Control Box. Connect wires to
Contactor and Ground Lug according to Wiring Diagram
on unit. Refer to Figure 9.

Route thermostat wiring through rubber grommet in
bottom of Control Box. Low voltage lead wires are
provided in the control box for connection to thermostat
wires (use wire nuts). Refer to Wiring Diagram on unit
and Figure 10 for low voltage wiring examples.

NOTE: Use No. 18 AWG (American Wire Gage)
color- coded, insulated (35 ° C minimum) wire. If
thermostat is located more than 100 feet (31 m) from unit
as measured along the control voltage wires, use No. 16
AWG color- coded wires to avoid excessive voltage
drop.

NOTE: Some models are factory equipped with Comfort
Alertt Diagnostics device. If Comfort Alert is used as a
field installed option, then a hot bundle must be run for
proper connection.

WARNING

INSTALLA TION INSTRUCTIONS R- 410A Split System Air Conditioner

Figure 9 Electrical Supply (Line Voltage) Connections

DISCONNECT

PER NEC AND/OR

LOCAL CODES

CONTACTO R

L1

11

FIELD POWER

WIRING

L2

23 or 13

FIELD GROUND

WIRING

GROUND

LUG

Figure 10 Typical Thermostat Connections

THERMOSTAT FURNACE

24 VAC HOT

24 VAC COM

COOL STAGE 1

INDOOR FAN

THERMOSTAT FAN COIL

24 VAC HOT

24 VAC COM

COOL STAGE 1

INDOOR FAN

R

C

W/W1

Y/Y2

G

R

C

W/W1

Y/Y2

G

R

C

WHEAT STAGE 1

Y

G

R

C

W2HEAT STAGE 1

Y

G

AIR CONDITIONER

C

AIR CONDITIONER

C

THERMOSTAT FAN COIL

24 VAC HOT

24 VAC COM

HEAT STAGE 1

COOL STAGE 1

INDOOR FAN

R

C

W/W1

Y/Y2

G

R

C

W2

Y

G

AC with Comfort Alert

C

Y

8 421 01 5103 05

INSTALLA TION INSTRUCTIONS R- 410A Split System Air Conditioner

START- UP PROCEDURE

1. Set indoor thermostat selector switch to OFF.

2. Turn ON all electrical disconnect devices.

3. If unit has a crankcase heater, energize the heater
and wait 24 hours before proceeding.

4. Set indoor thermostat at desired temperature. Be
sure setpoint is below indoor ambient temperature
or thermostat will not call for cooling.

5. Set indoor thermostat selector switch to COOL.
Operate unit for minimum 15 minutes, then check
the system refrigerant charge.

REFRIGERANT CHARGE

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

For TXV, use subcooling method.
For Piston, use superheat method.
To properly check or adjust charge, conditions must be

favorable for subcooling or superheat charging.
Favorable conditions exist when the outdoor
temperature is between 70_F and 100_F(21_C and
38_C), and the indoor temperature is between 70_F and
80_F(21_C and 27_C). Follow the procedure below.

Unit is factory charged for 15 feet (4.6 m) of lineset.
Adjust charge by adding or removing 0.6 oz/ft (17 g/mm)
of 3/8 liquid line above or below 15 feet (4.6 m)
respectively.

For standard refrigerant line lengths 80 feet (24.4 m) or
less, allow system to operate in cooling mode at least 15
minutes. If conditions are favorable, check system
charge by super heat method for fixed metering device
and subcooling method for TXV. 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(27_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(27_C) before
attempting to check system charge by subcooling
method as described above.

If the indoor temperature is below 70_F(21_C), or the
outdoor temperature is not in the favorable range, adjust
charge for line set length above or below 15 feet (4.6 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: If line length is beyond 80 feet (24.4 m) or greater
than 35 feet (10.7 m) vertical separation, See Long Line
Guideline for special charging requirements.

A. UNITS WITH COOLING MODE TXV

Units installed with cooling mode TXV require charging
by the subcooling method.

1. Operate unit a minimum of 15 minutes before
checking charge.

NOTE: If outdoor unit has a 2- speed fan motor,
motor will operate in low speed when outdoor
ambient temperature is below 82_F. Pull one of
the yellow low voltage wires off the fan control and
the unit will default to high speed fan for servicing.
Reconnect wire after servicing.

2. Measure liquid service valve pressure by
attaching an accurate gage to service port.

3. Measure liquid line temperature by attaching an
accurate thermistor type or electronic
thermometer to liquid line near outdoor coil.

4. Refer to unit rating plate for required subcooling
temperature.

5. Refer to Figure 13. Find the point where required
subcooling temperature intersects measured
liquid service valve pressure.

6. To obtain required subcooling temperature at a
specific liquid line pressure, add refrigerant if
liquid line temperature is higher than indicated or
reclaim refrigerant if temperature is lower. Allow a
tolerance of 

B. UNITS WITH INDOOR PISTON

Units installed with indoor pistons require charging by the
superheat method.

The following procedure is valid when indoor airflow is
within 21 percent of its rated CFM.

1. Operate unit a minimum of 15 minutes before
checking charge.

2. Measure suction pressure by attaching an
accurate gage to suction valve service port.

3. Measure suction temperature by attaching an
accurate thermistor type or electronic
thermometer to suction line at service valve.

4. Measure outdoor air dry- bulb temperature with
thermometer.

5. Measure indoor air (entering indoor coil) wet- bulb
temperature with a sling psychrometer.

6. Find outdoor temperature and evaporator
entering air wet- bulb temperature. At this
intersection, note superheat. Where a dash (- - )
appears on the table, do not attempt to charge
system under these conditions or refrigerant
slugging may occur. Charge must be weighted in,
adding or removing 0.6 oz/ft of 3/8 liquid line
above or below 15 feet (4.6 m) respectively .

7. Find superheat temperature (from #6 above) and
suction pressure. At this intersection, note suction
line temperature.

8. If unit has a higher suction line temperature than
charted temperature, add refrigerant until charted
temperature is reached.

9. If unit has a lower suction line temperature than
charted temperature, reclaim refrigerant until
charted temperature is reached.

10. When adding refrigerant, charge in liquid form into
suction service port using a flow- restricting
device.

1 1. If outdoor air temperature or pressure at suction

valve changes, charge to new suction line
temperature indicated on chart.

3_F(1.7_C).

421 01 5103 05 9

Specifications subject to change without notice.

INSTALLA TION INSTRUCTIONS R- 410A Split System Air Conditioner

12. Optimum performance will be achieved when
the operating charge produces 10_F suction
superheat at suction service valve with 95_F
(35_C) outdoor ambient and 80_F(27_C) dry
bulb (67_F/19_C) wet bulb) indoor
temperature (DOE “A” test conditions) at
rated airflow.

SUPERHEAT CHARGING TABLE

Figure 11

Outdoor

Temp

˚F 50 52 54 56 58 60 62 64 66 68 70 72 74 76 ˚C 10 11 12 13 14 16 17 18 19 20 21 22 23 24
55 9 12 14 17 20 23 26 29 32 35 37 40 42 45 13 5 7 8 9 11 13 14 16 18 19 21 22 23 25
60 7 10 12 15 18 21 24 27 30 33 35 38 40 43 16 4 6 7 8 10 12 13 15 17 18 19 21 22 24
65 - 6 10 13 16 19 21 24 27 30 33 36 38 41 18 - 3 6 7 9 11 12 13 15 17 18 20 21 23
70 - - 7 10 13 16 19 21 24 27 30 33 36 39 21 - - 4 6 7 9 11 12 13 15 17 18 20 22
75 - - - 6 9 12 15 18 21 24 28 31 34 37 24 - - - 3 5 7 8 10 12 13 16 17 19 21
80 - - - - 5 8 12 15 18 21 25 28 31 35 27 - - - - 3 4 7 8 10 12 14 16 17 19
85 - - - - - - 8 11 15 19 22 26 30 33 29 - - - - - - 4 6 8 11 12 14 17 18
90 - - - - - - 5 9 13 16 20 24 27 31 32 - - - - - - 3 5 7 9 11 13 15 17
95 - - - - - - - 6 10 14 18 22 25 29 35 - - - - - - - 3 6 8 10 12 14 16

100 - - - - - - - - 8 12 15 20 23 27 38 - - - - - - - - 4 7 8 11 13 15
105 - - - - - - - - 5 9 13 17 22 26 41 - - - - - - - - 3 5 7 9 12 14
110 - - - - - - - - - 6 11 15 20 25 43 - - - - - - - - - 3 6 8 11 14
115 - - - - - - - - - - 8 14 18 23 46 - - - - - - - - - - 4 8 10 13

*Optimum perfor ma nce point, 95° F (35° C) outdoor ambient and (80° F / 27° C dry bul b), (67° F / 19° C wet bulb) indoor conditions. (D OE A Test C onditions)
Where a dash ( - - ) appears do not attempt to charge system under these conditions or refrigerant slugging may occur. Charge must be weighed in.

Note: Superheat ° F is at low - side service port, Allow a tolerance of ± 3° F (± 1.7°C)
Note: Indoor dry bulb between 70° F and 80° F (21° C and 27° C)

Figure 12 SUCTION PRESSURE AT SERVICE PORT PSIG SUCTION PRESSURE AT SERVICE PORT kPA

SUPER-

HEAT

TEMP F

0 35 37 39 41 43 45 47 49 51 0 2 3 4 5 6 7 8 9 11
2 37 39 41 43 45 47 49 51 53 1 3 4 5 6 7 8 9 11 12
4 39 41 43 45 47 49 51 53 55 2 4 5 6 7 8 9 11 12 13
6 41 43 45 47 49 51 53 55 57 3 5 6 7 8 9 11 12 13 14

8 43 45 47 49 51 53 55 57 59 4 6 7 8 9 11 12 13 14 15
10 45 47 49 51 53 55 57 59 61 6 7 8 9 11 12 13 14 15 16
12 47 49 51 53 55 57 59 61 63 7 8 9 11 12 13 14 15 16 17
14 49 51 53 55 57 59 61 63 65 8 9 11 12 13 14 15 16 17 18
16 51 53 55 57 59 61 63 65 67 9 11 12 13 14 15 16 17 18 19
18 53 55 57 59 61 63 65 67 69 10 12 13 14 15 16 17 18 19 21
20 55 57 59 61 63 65 67 69 71 11 13 14 15 16 17 18 19 21 22
22 57 59 61 63 65 67 69 71 73 12 14 15 16 17 18 19 21 22 23
24 59 61 63 65 67 69 71 73 75 13 15 16 17 18 19 21 22 23 24
26 61 63 65 67 69 71 73 75 77 14 16 17 18 19 21 22 23 24 25
28 63 65 67 69 71 73 75 77 79 16 17 18 19 21 22 23 24 25 26
30 65 67 69 71 73 75 77 79 81 17 18 19 21 22 23 24 25 26 27

(SUPERHEAT ˚F AT LOW-SIDE SERVICE PORT)

EVAPORATOR ENTEREING AIR ˚F AT WB Outdoor

˚F = Fahrenheit ˚C = Celsius

108 112 11 7 121 126 131 139 141 146 SUPER-

REQUIRED SUCTION TUBE TEMPERATURE ˚F

(MEASURED AT LOW- SIDE SERVICE PORT)

Temp

HEAT

TEMP C

SUPERHEAT CHARGING TABLE

(SUPERHEAT ˚C AT LOW-SIDE SERVICE PORT)

EVAPORATOR ENTEREING AIR ˚C AT WB

743 774 805 836 869 902 957 971 1005

REQUIRED SUCTION TUBE TEMPERATURE ˚C

(MEASURED AT LOW- SIDE SERVICE PORT)

10 421 01 5103 05

INSTALLA TION INSTRUCTIONS R- 410A Split System Air Conditioner

Figure 13 Rating Plate (required) Subcooling Temperature ° F(° C)

° F (° C) ° F (° C) ° F (° C) ° F (° C) F (° C) F (° C)

Measured Liquid

6 3 8 4 10 6 12 7 14 8 16 9

Pressure (psig)

R- 410A Required Liquid Line Temperature ° F(° C)

251 78 26 76 24 74 23 72 22 70 21 68 20
259 80 27 78 26 76 24 74 23 72 22 70 21
266 82 28 80 27 78 26 76 24 74 23 72 22
274 84 29 82 28 80 27 78 26 76 24 74 23
283 86 30 84 29 82 28 80 27 78 26 76 24
291 88 31 86 30 84 29 82 28 80 27 78 26
299 90 32 88 31 86 30 84 29 82 28 80 27
308 92 33 90 32 88 31 86 30 84 29 82 28
317 94 34 92 33 90 32 88 31 86 30 84 29
326 96 36 94 34 92 33 90 32 88 31 86 30
335 98 37 96 36 94 34 92 33 90 32 88 31
345 100 38 98 37 96 36 94 34 92 33 90 32
364 104 40 102 39 100 38 98 37 96 36 94 34
374 106 41 104 40 102 39 100 38 98 37 96 36
384 108 42 106 41 104 40 102 39 100 38 98 37
395 110 43 108 42 106 41 104 40 102 39 100 38
406 112 44 110 43 108 42 106 41 104 40 102 39
416 114 46 112 44 110 43 108 42 106 41 104 40
427 116 47 114 46 112 44 110 43 108 42 106 41
439 118 48 116 47 114 46 112 44 110 43 108 42
450 120 49 118 48 116 47 114 46 112 44 110 43
462 122 50 120 49 118 48 116 47 114 46 112 44
474 124 51 122 50 120 49 118 48 116 47 114 46

421 01 5103 05 11

Specifications subject to change without notice.

INSTALLA TION INSTRUCTIONS R- 410A Split System Air Conditioner

SEQUENCE OF OPERATION

With power supplied to indoor and outdoor units,
transformer is energized.

On a call for cooling, the thermostat makes circuits R- Y
and R- G. Circuit R- Y energizes contactor, starting
outdoor fan motor and compressor. Circuit R- G
energizes indoor unit blower relay , starting indoor blower
motor.

When thermostat is satisfied, its contacts open,
de- energizing contactor and blower relay. Compressor
and motors stop.

NOTE: If indoor unit is equipped with a time- delay relay
circuit, the blower runs an additional length of time to
increase system efficiency.

TROUBLESHOOTING

Some models are factory equipped with the Comfort
Alertt Diagnostics device in the control box (refer to
Figure 14). Comfort Alert provides around- the- clock
monitoring for common electrical problems, compressor
defects, and broad system faults. If trouble is detected,
an alert code is displayed with a flashing LED indicator.
Alert codes are listed in Figure 15.

The device is factory wired and requires no
modification.Low voltage lead wires are provided in the

control box for connection to thermostat wires (use wire
nuts).

The Comfort Alert device operates by monitoring the
compressor power leads and the thermostat demand
signal (Y terminal).

MAINTENANCE

Condensate Drain

During the cooling season, check monthly for free flow of
drainage and clean if necessary.

Cleanliness

These tips will help keep the air conditioner looking better
and working more efficiently:

1. Free flow of air is essential. Keep fences, shrubs,
trash cans, and other obstructions at least 18
inches (457 mm) from all coil inlets.

2. Keep the coil free of grass clippings, leaves,
weeds, and other debris.
NOTE: Coil may occasionally require cleaning
with a liquid solution. The coil must be cold when
cleaning. Use an alkaline based cleaner only .
Cleaning a hot coil or using an acid based cleaner
will remove the paint from the fins and may clog
the coil.

3. Never use a weather cover over the outdoor unit
unless it is a ventilated type or made of breathable
fabric that will allow moisture to evaporate rapidly .
A cover that holds moisture in the unit will cause
more rust build- up and damage than normal
exposure to weather.

Figure 14

See Figure 19 for the 24 and 30 sizes for the *4A3 series.

Comfort Alertt Diagnostics

(some models)

Compressor Wires
Pass Through Holes (3)

24 VAC Common

Thermostat Demand

12 421 01 5103 05

INSTALLA TION INSTRUCTIONS R- 410A Split System Air Conditioner

Figure 15 Comfort Alertt Diagnostics (*XA6 all sizes - *4A3 sizes 18, 36- 60 only)

Status LED Status LED Description Status LED Troubleshooting Information
Green “POWER” Module has power Supply voltage is present at module terminals
Red “TRIP” Thermostat demand signal

Y1 is present, but the
compressor is not running

1. Compressor protector is open

2. Outdoor unit power disconnect is open

3. Compressor circuit breaker or fuse(s) is open

4. Broken wire or connector is not making contact

5. Low pressure switch open if present in system

6. Compressor contactor has failed open

Yellow “ALERT”
Flash Code 1

Long Run Time

Compressor is running
extremely long run cycles

1. Low refrigerant charge

2. Evaporator blower is not running

3. Evaporator coil is frozen

4. Faulty metering device

5. Condenser coil is dirty

6. Liquid line restriction (filter drier blocked if present in system)

7. Thermostat is malfunctioning

Yellow “ALERT”
Flash Code 2

Yellow “ALERT”
Flash Code 3

System Pressure Trip

Discharge or suction
pressure out of limits or
compressor overloaded

Short Cycling

Compressor is running
only briefly

1. High head pressure

2. Condenser coil poor air circulation (dirty, blocked, damaged)

3. Condenser fan is not running

4. Return air duct has substantial leakage

1. If high pressure switch open, go to Flash Code 2 information

2. If low pressure switch open, go to Flash Code 1 information

3. Thermostat demand signal is intermittent

4. Loose wiring at contactor coil

Yellow “ALERT”
Flash Code 4

Locked Rotor

1. Run capacitor has failed

2. Low line voltage (contact utility if voltage at disconnect is low)

3. Excessive liquid refrigerant in compressor

4. Compressor bearings are seized

Yellow “ALERT”
Flash Code 5

Open Circuit

1. Outdoor unit power disconnect is open

2. Compressor circuit breaker or fuse(s) is open

3. Compressor contactor has failed open

4. High pressure switch is open and requires manual reset

5. Open circuit in compressor supply wiring or connections

6. Unusually long compressor protector reset time due to
extreme ambient temperature

7. Compressor windings are damaged

Yellow “ALERT”
Flash Code 6

Open Start Circuit

Current only in run circuit

1. Run capacitor has failed

2. Open circuit in compressor start wiring or connections

3. Compressor start winding is damaged

Yellow “ALERT”
Flash Code 7
Yellow “ALERT”
Flash Code 9

Open Run Circuit

Current only in start circuit

Low Voltage

Control circuit < 17VAC

1. Open circuit in compressor run wiring or connections

2. Compressor run winding is damaged

1. Control circuit transformer is overloaded

2. Low line voltage (contact utility if voltage at disconnect is low)

S Flash Code number corresponds to a number of LED flashes, followed by a pause and then repeated.
S TRIP and ALERT LEDs flashing at same time means control circuit voltage is too low for operation.

421 01 5103 05 13

Specifications subject to change without notice.

INSTALLA TION INSTRUCTIONS R- 410A Split System Air Conditioner

ELECTRICAL WIRING
(for *4A3, sizes 24 and 30 only)

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. To furnish
power to heater only, set thermostat to OFF and close
electrical disconnect to outdoor unit.

A crankcase heater is required for low - ambient cooling or if
refrigerant tubing is longer than 80 ft. (24.38 m). Refer to the
Long Line Applications Guideline - Residential Split- System
Air Conditioners and Heat Pumps Using R - 410A Refrigerant.

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. 16.

Figure 17

Outdoor Coil Thermistor (OCT) Attachment

OCT Thermistor must be

secured tight on the liquid tube.

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:

S Do not overcharge system with refrigerant.
S Do not operate unit in a vacuum or at negative

pressure.

S Do not disable low pressure switch in scroll compressor

applications.

S Dome temperatures may be hot.

CAUTION

Figure 16

OAT Thermistor must be locked in place

with spherical nib end facing towards

the front of the control box

The Outdoor Coil Temperature (OCT) Thermistor is factory
installed on the liquid tube between the coil assembly and the
liquid service valve. See Fig. 17.

Check to make sure the thermistor is securely attached on
the liquid tube with the clip as shown in Fig. 17.

Outdoor Air Thermistor (OAT) Attachment

DX+ DX- C R

!

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:

S 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.

CAUTION

CAUTION

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.

14 421 01 5103 05

INSTALLA TION INSTRUCTIONS R- 410A Split System Air Conditioner

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

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 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
“efficiency” 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
temperaturetodropto80_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: 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.

Major Components

Control Board

The AC control board controls the following functions:

S Compressor contactor operation
S Outdoor fan motor operation
S Compressor external protection
S Pressure switch monitoring
S Time Delays

Field Connections

When using communicating control, 4 field wires are required
to be connected to the factory wires already wired to the
DX+DX- C R terminal (see Fig. 20). Unit as provided by
manufacturer is set up for communicating control.

When used with a standard non- communicating thermostat,
it is recommended to use 3 thermostat control wires to be
connected to R, Y and C. When using 3 wires, all diagnostic
and time delay features are enabled (See Fig. 21).

Disconnect factory provided wires from DX+, DX- , C & R
terminals. Using factory provided wires, connect to R, C, and
Y on the control board for 3 wire thermostat control. Connect
field 24V wires to factory provided wires now connected to R,
C, and Y and cap both sides or remove unused factory
provided wires.

When only 2 thermostat control wires are available, units will
function, but some control features are lost. (See Fig. 22).
With only 2 wires connected, the circuit board will be
powered down whenever there is no call for cooling, and the
following will result:

S Compressor time delay is reduced from 5 minutes to 10

seconds

S When the thermostat is not calling for cooling, the amber

status light will be off, and no diagnostics codes will be
available

S All system counters will be reset on each new call for

cooling

Disconnect factory provided wires from DX+, DX- , C and R
terminals. Using factory provided wires, connect to C and Y
on the control board for 2 wire thermostat control. A field
installed jumper wire is also required between R and Y (See
Fig. 22). Connect field 24V wires to factory provided wires
now connected to C and Y and cap both sides or remove
unused factory provided wires.

Compressor Internal Relief

The compressor is protected by an Internal Pressure Relief
(IPR) which relieves discharge gas into the compressor shell
when differential between suction and discharge pressure
exceeds 550- 625 psi. The compressor is also protected by
an internal overload attached to motor windings.

GENERAL SEQUENCE OF OPERATION

STANDARD THERMOSTAT

Turn on power to indoor and outdoor units. Transformer is
energized.

On a call for cooling, thermostat makes circuits R- Y and
R- G. Circuit R- Y energizes contactor, starting outdoor fan
motor and compressor circuit. R - G energizes indoor unit
blower relay, starting indoor blower motor on high speed.

NOTE: To achieve the rated system performance, the indoor
unit or the thermostat must be equipped with a time delay
relay circuit.

When thermostat is satisfied, its contacts open,
de- energizing contactor and blower relay. Compressor and
motors stop. If indoor unit is equipped with a time- delay relay
circuit, the indoor blower will run an additional 90 sec to
increase system efficiency.

CONTROL FUNCTIONS

AND SEQUENCE OF OPERATION

The outdoor unit control system has special functions. The
following is an overview of the control functions.

SEQUENCE OF OPERATION

Cooling Operation

This product utilizes either a standard indoor thermostat or
Observer t Communicating Wall Control. With a call for
cooling, the outdoor fan and compressor are energized.
When the cooling demand is satisfied, the compressor and
fan will shut off.

NOTE: The outdoor fan motor will continue to operate for one
minute after compressor shuts off, when the outdoor ambient
is greater than or equal to 100_F (37.78_C).

421 01 5103 05 15

Specifications subject to change without notice.

INSTALLA TION INSTRUCTIONS R- 410A Split System Air Conditioner

Communication and Status Function Lights

Green Communications (COMM) Light (Communicating
Control only):

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 c ommunication is
received within 2 minutes, the LED will be turned OFF until
the next valid communication.

Amber Status Light

An amber colored STATUS light is used to display the
operation mode and fault codes as specified in the
troubleshooting section. See Table 1 for codes and
definitions.

NOTE: Only one fault code will be displayed on the outdoor
unit control board (the most recent, with the highest priority).

Crankcase Heater Operation

The crankcase heater (when applicable) is energized during
the off cycle below 65_F (37.78_C)

Outdoor Fan motor Operation

The outdoor unit control energizes outdoor fan any time the
compressor is operating. The outdoor fan remains energized
for 15 minutes if a pressure switch or compressor thermal
protector 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
(37.78_C).

Time Delays

The unit time delays include:

S Five minute time delay to start cooling operation when

there is a call from the thermostat or communicating wall
control.

S When operating the unit with 2 wires, this delay is

shortened to 10 seconds.

S Five minute compressor recycle delay on return from a

brown out condition

S Two minute time delay to return to standby operation from

last valid communications (with communicating only)

S One minute time delay of outdoor fan at termination of

cooling mode when outdoor ambient is greater than or
equal to 100_F (37.78_C).

Utility Interface

With Non- Communicating Thermostats

Utility curtailment will only work when the unit is operating
with a non- communicating thermostat.

When the utility curtailment interface is applied with a
non- communicating thermostat, the utility relay should be
wired in series with the Y input.

Low Ambient Cooling

With Non- Communicating Thermostats

When this unit is required to operate below 55_F (12.78_C) to
a m inimum of 0 _ F (- 17.78 _C) outdoor temperature,
provisions must be made for low ambient operation.

Low ambient applications re quire the ins tallation of
accessory kits:

S Low Ambient Pressure Switch Kit
S Evaporator Freeze Thermostat
S Winter Start Control
S Hard Start kit
S Crankcase Heater

Support feet are recommended for low ambient cooling. See
Product Specification sheet for kit part numbers on
appropriate unit size and series unit.

For low ambient cooling with the Observer
Communicating Wall Control the cooling lockout must be
set to “Off” in the Wall Control setup.

Liquid Line Solenoid

When operating in communicating mode the standard
thermostat terminals will not function. A terminal on the
non- communicating thermostat bus labeled “LS” on the AC
control board is provided for wiring liquid line solenoids when
in communicating mode. For operation in communicating
mode wire solenoid valve kit NASA401LS across LS and C
terminals . For operation in non- communicating mode wire
solenoid valve kit NASA401LS across C and Y terminals.

If the thermal cutout trips for three consecutive cycles, then
unit operation is locked out for 4 hours and the appropriate
fault code (See Table 1) is displayed.

CONTACTOR SHORTED DETECTION

If there is compressor voltage sensed when there is no
demand for compressor operation, the contactor may be
stuck closed. The control will flash the appropriate fault
code. Check the contactor and control box wiring.

NO 230V AT COMPRESSOR

If the compressor voltage is not sensed when the
compressor should be starting, the contactor may be stuck
open or the unit disconnect or circuit breaker may be open.
The control will flash the appropriate fault code. Check the
contactor, unit disconnect or circuit breaker and control box
wiring.

TEMPERATURE THERMISTORS

Thermistors are electronic devices which sense temperature.
As the temperature increases, the resistance decreases.
Thermistors are used to sense outdoor air (OAT) and coil
temperature (OCT).

If the outdoor air or coil thermistor should fail, the control will
flash the appropriate fault code. (See table 1).

IMPORTANT: The outdoor air thermistor and coil thermistor
are factory mounted in the correct locations. Do not re- locate
thermistor sensors.

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( - 12.22_C) warmer
than the coil sensor (or) the outdoor air sensor indicates
20_F( -6.67_C) cooler than the coil sensor, the sensors
are out of range.

If the sensors are out of range, the c ontrol will flash the
appropriate fault code. (See Table 1).

FAILED THERMISTOR DEFAULT OPERATION

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

Thermistor Curve: The resistance vs. temperature chart
shown in Figure 18 enables the technician to check the
outdoor air and outdoor coil thermistors for proper resistance.
Unplug the thermistor assembly from the circuit board and
measure resistance across each thermistor. For example, if
the outdoor temperature is 60_F (15.56_C), the resistance
reading across the outdoor air thermistor should be around
16,000 Ohms.

16 421 01 5103 05

INSTALLA TION INSTRUCTIONS R- 410A Split System Air Conditioner

STATUS CODES

Table 3 shows the status codes flashed by the amber status
light. Most system problems can be diagnosed by reading
the status code as flashed by the amber status light on the
control board.

The codes are flashed by a series of short and long flashes
of the status light. The short flashes indicate the first digit in
the status code, followed by long flashes indicating the
second digit of the error code. The short flash is 0.25 second

ON and the long flash is 1.0 second ON. Time between
flashes is 0.25 second. Time between short flash and first
long flash is 1.0 second. Time between code repeating is 2.5
seconds with LED OFF.

Count the number of short and long flashes to determine the
appropriate flash code. Table 1 gives possible causes and
actions related to each error.

Example: 3 short flashes followed by 2 long flashes indicates
a 32 code. Table 1 shows this to be low pressure switch
open.

Table 1 - Status Codes

OPERATION FAUL T

Standby – no call
for unit operation

Standby – no call
for unit operation

Cooling Operation None 1, pause Normal operation

Outdoor Air Temp Sensor

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

None On solid, no flash Normal operation - with communicating Control

None Off

System Communications

Failure

High Pressure

Switch Open

Low Pressure

Switch Open

Control Fault 45

Brown Out

(24 v)

Fault

Thermistors out

of range

Thermal Cutout 72

Contactor Shorted 73

No 230V at

Compressor

Thermal Lockout 82

Low Pressure Lockout 83

High Pressure

Lockout

AMBER LED

FLASH CODE

Normal operation - No call for cooling with 2 - wire connection or indoor unit not pow-

ered.

16

31

32 Low pressure switch trip. Check refrigerant charge and indoor air flow

46

53 Outdoor air sensor not reading or out of range. Ohm out sensor and check wiring

56

74

84

Communication with wall control lost. Check wiring to wall control, indoor and outdoor

units

High pressure switch trip. Check refrigerant charge, outdoor fan operation and coils

for airflow restrictions.

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

The control voltage is less than 15.5v for at least 4 seconds. Compressor and fan
operation not allowed until control voltage is a minimum of 17.5v. Verify control volt­age.

Improper relationship between coil sensor and outdoor air sensor. Ohm out sensors
and check wiring.

Compressor voltage sensed after start- up, then absent for 10 consecutive seconds
while cooling demand exists. Possible causes are internal compressor overload trip or
loss of high voltage to compressor without loss of control voltage. The control will
continue fan operation and wait 15 minutes to attempt a restart. Fault will clear when
restart is successful, or low voltage power is cycled.

Compressor voltage sensed when no demand for compressor operation exists. Con­tactor may be stuck closed or there is a wiring error.

Compressor voltage not sensed when compressor should be starting. Disconnect may
be open or contactor may be stuck open or there is a wiring error.

Thermal cutout occurs in three consecutive cycles. Unit operation locked out for 4
hours or until 24v power recycled.

Low pressure switch trip has occurred during 3 consecutive cycles. Unit operation
locked out for 4 hours or until 24v power recycled.

High pressure switch trip has occurred during 3 consecutive cycles. Unit operation
locked out for 4 hours or until 24v power recycled.

Possible Cause and Action

421 01 5103 05 17

Specifications subject to change without notice.

INSTALLA TION INSTRUCTIONS R- 410A Split System Air Conditioner

Figure 18 Resistance vs Temperature Chart

THERMISTOR CURVE

90

80

70

60

50

40

30

20

RESISTANCE (KOHMS)

10

0

0

(-17.77)20(-6.67)40(4.44)60(15.56)80(26.67)

TEMPERATURE °F (°C)

Figure 19 Single Stage Control Board (*4A3 only, sizes 24 & 30)

100

(37.78)

120

(48.89)

A08054

18 421 01 5103 05

INSTALLA TION INSTRUCTIONS R- 410A Split System Air Conditioner

Figure 20

Wall Control

DX+

DX-

C

R

S1

S2

Figure 21

Optional Remote

Room Sensor

Observer Communicating Wall Control Four- Wire Connection Wiring Diagrams

(See Thermostat Installation Instructions for specific unit combinations)

Variable Speed

Green

Y ellow

White

Red

Humidifier

Connection

Furnace/Fan Coil

DX+

DX-

C

R

HUM

COM

Green

Y ellow

White

Red

Outdoor

DX+

DX-

C

R

LEGEND

24V FACTORY WIRING

24V FIELD WIRING

FIELD SPLICE CONNECTION

Non- Communicating Standard Thermostat 3 - Wire 24V Circuit Connections

(See Thermostat Installation Instructions for

Specific Unit combinations)

LEGEND

24- V FACTORY WIRING

24- V FIELD WIRING

FIELD SPLICE CONNECTION

!

CAUTION

ELECTRICAL OPERATION HAZARD

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

A minimum of three wire thermostat wiring is
required for the system to operate.

421 01 5103 05 19

Specifications subject to change without notice.

INSTALLA TION INSTRUCTIONS R- 410A Split System Air Conditioner

Figure 22

A/C THERMOSTAT

24VAC HOT

24VAC COM

HEAT STAGE 1

HEAT STAGE 2

INDOOR FAN

R

C

W/W1

Y/Y2

G

Non- Communicating Standard Thermostat

NOTE: Wiring must conform to NEC or local codes.

2- Wire 24V Circuit Connections

TPPICAL FURNACE

OR

FAN C OIL

R

C

W

Y

G

LEGEND

24V FACTORY WIRING

24V FIELD WIRING

FIELD SPLICE CONNECTION

AIR CONDITIONER

R

C

Y

FIELD INSTALLED JUMPER WIRE

Figure 23

Non- Communicating Indoor with Observer Communicating Wall Control

Wall

Control

DX+

R

C

DX-

C

R

W2

Y/Y2

G

Non-Communicating

Indoor

NOTE: This installation requires the daughter board
accessory, NAXA00101DB.
NOTE: This installation does not allow for communicating
feature functionality.

Green

Red

White

Yellow

NAXA00101DB

DX+

R

C

DX-

C

R

W2

Y

G

O





OAT

Communicating

Outdoor

C

R

Y

OAT

Sensor

20 421 01 5103 05

INSTALLA TION INSTRUCTIONS R- 410A Split System Air Conditioner

R- 410A QUICK REFERENCE GUIDE

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

 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.

 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.

 DonotusewithanR-22TXV.

 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.

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

 Do not use capillary tube indoor coils.

421 01 5103 05 21

Specifications subject to change without notice.

Copyright 2017 International Comfort Products

Lewisburg, TN 37091 USA