Carrier 24APA Installation Instructions Manual - User Manual

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Installation Instructions

24APA

Performance

Series Air Conditioner

with Puron

Refrigerant

1---1/2 to 5 Nominal Tons (Size 18 To 60)

the environmentally sound refrigerant

Fig. 1

---

24APA

NOTE

: Read the entire instruction manual before starting the

installation.

TABLE OF CONTENTS

PAGE

SAFETY CONSIDERATIONS

. . . . . . . . . . . . . . . . . . . . . .

INSTALLATION RECOMMENDATIONS

. . . . . . . . . . . .

INSTALLATION

3 -- 9, 14

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Step 1 -- Check Equipment & Jobsite

. . . . . . . . . . . . . . . .

Step 2 -- Install on Solid Pad

. . . . . . . . . . . . . . . . . . . . . .

Step 3 -- Clearance Requirements

. . . . . . . . . . . . . . . . . . .

Step 4 -- Operating Ambient

. . . . . . . . . . . . . . . . . . . . . . .

Step 5 -- Install TXV

3 -- 4

. . . . . . . . . . . . . . . . . . . . . . . . .

Step 6 -- Make Piping Connections

5 -- 7

. . . . . . . . . . . . . .

Step 7 -- Make Electrical Connections

7 -- 8

. . . . . . . . . . . .

Step 8 -- Compressor Crankcase Heater

. . . . . . . . . . . . . .

Step 9 -- Install Electrical Accessories

. . . . . . . . . . . . . .

Step 10-- Check OCT and OAT Thermistor Attachment

. .

Step 11 -- Start--Up

8 -- 9

. . . . . . . . . . . . . . . . . . . . . . . . . . .

Step 12 -- Check Charge

9, 14

. . . . . . . . . . . . . . . . . . . . . . .

GENERAL SEQUENCE OF OPERATION

. . . . . . . . . . . .

CONTROL FUNCTIONS

AND SEQUENCE OF OPERATION

10 -- 11

. . . . . . . . . . . . .

TROUBLESHOOTING

11 -- 12

. . . . . . . . . . . . . . . . . . . . . . . .

FINAL CHECKS

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CARE AND MAINTENANCE

. . . . . . . . . . . . . . . . . . . . . .

SUBCOOLING TABLE

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

24 VOLT CONNECTION DIAGRAMS

15 -- 16

. . . . . . . . . . .

PURON

REFRIGERANT QUICK REF. GUIDE

. . . . .

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 National Electrical Code (NEC) for special requirements.

Recognize safety information. This is the safety--alert symbol

When you see this symbol on the unit and in instructions or

manuals, be alert to the potential for personal injury. Understand
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.

WARNING

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.

WARNING

UNIT OPERATION AND SAFETY HAZARD

Failure to follow this warning could result in personal injury

or equipment damage.
Puron

refrigerant systems operate at higher pressures than

standard R--22 systems.

Do not use R--22 service

equipment or components on Puron refrigerant equipment.

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. 2.)

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. 2.)

8. Ensure that tubing insulation is pliable and completely

surrounds vapor tube.

9. When necessary, use hanger straps which are 1 in. wide

and conform to shape of tubing insulation. (See Fig. 2.)

10. Isolate hanger straps from insulation by using metal

sleeves bent to conform to shape of insulation.

INSULATION

VAPOR TUBE

LIQUID TUBE

OUTDOOR WALL

INDOOR WALL

LIQUID TUBE

VAPOR TUBE

INSULATION

CAULK

Avoid contact between tubing and structure

NOTE:

THROUGH THE WALL

HANGER STRAP
(AROUND VAPOR

TUBE ONLY)

JOIST

1” MIN.

SUSPENSION

A94026

Fig. 2

---

Connecting Tube Installation

Outdoor unit contains system refrigerant charge for operation

with ARI rated indoor unit when connected by 15 ft. 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.

24AP

INSTALLATION

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 presale literature. There

can be no deviation. Consult the Application Guideline and
Service Manual – Air Conditioners and Heat Pumps Using

Puron

Refrigerant to obtain required unit changes for specific

applications and for R--22 retrofit.

STEP 1

—

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.

STEP 2

—

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.
3 to determine base pan size and knockout hole location.
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 Application Guideline and Service Manual --
Residential Split System Air Conditioners and Heat Pumps Using

Puron

Refrigerant for wind baffle construction.

NOTE

: Unit must be level to within

(

3/8 in./ft..) per

compressor manufacturer specifications.

STEP 3

—

Clearance Requirements

When installing, allow sufficient space for airflow clearance,

wiring, refrigerant piping, and service. Allow 30--in. clearance to
service end of unit and 48 in. above unit. For proper airflow, a

6--in. clearance on 1 side of unit and 12 in. on all remaining sides
must be maintained. Maintain a distance of 24 in. between units.

Position so water, snow, or ice from roof or eaves cannot fall

directly on unit.

VIEW

FROM

TOP

3/8--IN.

DIA.

TIEDOWN

KNOCKOUTS IN BASEPAN

(2) PLACES

UNIT BASE PAN

DIMENSIONS

TIEDOWN KNOCKOUT LOCATIONS

29---1/2 X 33

10–1/16

5–5/8

23–3/4

36–1/2 X 40

9–5/8

6–13/16

28–3/4

A05177

Fig. 3

---

Tiedown Knockout Locations

On rooftop applications, locate unit at least 6 in. above roof
surface.

STEP 4

—

Operating Ambient

The minimum outdoor operating ambient in cooling mode is
55

F, and the maximum outdoor operating ambient in cooling

mode is 125

STEP 5

—

Install TXV

NOTE

: Applies to rated non--TXV and R--22 TXV indoor units

only. If installing a rated and approved indoor coil without a
factory installed Puron

TXV, remove and replace the fixed

orifice or R--22 TXV expansion device with a hard shutoff Puron
TXV.
The thermostatic expansion valve is specifically designed to
operate with Puron refrigerant. Do not use an R--22 TXV. An

existing R--22 TXV must be replaced with a factory--approved

TXV specifically designed for Puron refrigerant. Refer to
Product Data Sheet for the appropriate TXV kit number.

CAUTION

UNIT OPERATION HAZARD

Failure to follow this caution may result in equipment

damage or improper operation.
Al indoor coil units must be installed with a hard shut

off Puron

TXV metering device.

IMPORTANT

: The TXV should be mounted as close to the

indoor coil as possible and in a vertical, upright position. Avoid
mounting the inlet tube vertically down. Valve is more
susceptible to malfunction due to debris if inlet tube is facing
down. A factory--approved filter drier must be installed in the
liquid line.

24AP

Installing TXV in Place of Piston in a Rated Indoor Coil
(pre--2006)

1. Pump system down to 2 psig and recover refrigerant.
2. Remove hex nut from piston body. Use backup wrench on

fan coils.

3. Remove and discard factory--installed piston. Be sure

Teflon seal is in place.

4. Reinstall hex nut. Finger tighten nut plus 1/2 turn.

NOTE

: If the piston is not removed from the body, TXV will

not function properly.

CAUTION

EQUIPMENT DAMAGE HAZARD

Failure to follow this caution may result in equipment

damage or improper operation.
Use a brazing shield and wrap TXV with wet cloth or

use heat sink material

5. Install TXV on indoor coil liquid line. Sweat swivel

adapter to inlet of indoor coil and attach to TXV outlet.
Use backup wrench to avoid damage to tubing or valve.
Sweat inlet of TXV, marked “IN” to liquid line. Avoid

excessive heat which could damage valve.

6. Install vapor elbow with equalizer adapter to suction tube

of line set and suction connection to indoor coil. Adapter
has a 1/4--in. male connector for attaching equalizer tube.

7. Connect equalizer tube of TXV to 1/4--in. equalizer fitting

on vapor line adapter.

8. Attach TXV bulb to horizontal section of suction line

using clamps provided. Insulate bulb with field--supplied
insulation tape. See Fig. 4 for correct positioning of

sensing bulb.

9. Proceed with remainder of unit installation.

2 O’CLOCK

10 O’CLOCK

SENSING BULB

STRAP

SUCTION TUBE

8 O’CLOCK

4 O’CLOCK

IN. OD & SMALLER

LARGER THAN 7/8 IN. OD

7/8

A81032

Fig. 4

---

Position of Sensing Bulb

Replacing TXV on a Rated R--22 Indoor Coil (pre--2006)

1. Pump system down to 2 psig and recover refrigerant.
2. Remove coil access panel and fitting panel from front of

cabinet.

3. Remove TXV support clamp using a 5/16--in. nut driver.

Save the clamp.

4. Remove R--22 TXV using a backup wrench on flare

connections to prevent damage to tubing.

5. Using wire cutters, cut equalizer tube off flush with vapor

tube inside cabinet.

6. Remove bulb from vapor tube inside cabinet.
7. Braze equalizer stub--tube closed. Use protective barrier as

necessary to prevent damage to drain pan.

IMPORTANT

: Route the equalizer tube of Puron TXV through

suction line connection opening in fitting panel prior to replacing
fitting panel around tubing.

8. Install TXV with 3/8--in. copper tubing through small hole

in service panel. Use wrench and backup wrench, to avoid

damage to tubing or valve, to attach TXV to distributor.

9. Reinstall TXV support clamp (removed in item 3).

10. Attach TXV bulb to vapor tube inside cabinet, in same

location as original was when removed, using supplied
bulb clamps (nylon or copper). See Fig. 4 for correct

positioning of sensing bulb.

11. Route equalizer tube through suction connection opening

(large hole) in fitting panel and install fitting panel in
place.

12. Sweat inlet of TXV, marked “IN” to liquid line. Avoid

excessive heat which could damage valve.

13. Install vapor elbow with equalizer adapter to vapor line of

line set and vapor connection to indoor coil. Adapter has
a 1/4--in. male connector for attaching equalizer tube.

14. Connect equalizer tube of TXV to 1/4--in. equalizer fitting

on vapor line adapter. Use backup wrench to prevent
damage to equalizer fitting.

15. Proceed with remainder of unit installation.

24AP

STEP 6

—

Make Piping Connections

WARNING

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.

CAUTION

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.

CAUTION

UNIT DAMAGE HAZARD

Failure to follow this caution may result in equipment

damage or improper operation.
If ANY refrigerant tubing is buried, provide a 6 in. vertical

rise at service valve. Refrigerant tubing lengths up to 36 in.

may be buried without further special consideration. Do

not bury lines longer than 36 in.

CAUTION

UNIT DAMAGE HAZARD

Failure to follow this caution may result in equipment

damage or improper operation.
To prevent damage to unit or service valves observe the

following:

Use a brazing shield.

Wrap service valves with wet cloth or use a heat sink

material.

Outdoor units may be connected to indoor section using

accessory tubing package or field--supplied refrigerant grade

tubing of correct size and condition. Rated tubing diameters
shown in Table 1 recommended up to 80 ft. See Product Data

for acceptable alternates vapor diameters and associated capacity
losses. For tubing requirements beyond 80 ft., substantial

capacity and performance losses can occur. Following the

recommendations in the Longline Guideline -- Residential
Split--System Air Conditioners and Heat Pumps Using Puron

Refrigerant will reduce these losses. Refer to Table 1 for field
tubing diameters. Refer to Table 2 for accessory requirements.
There are no buried--line applications greater than 36 in.
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 ARI rated indoor unit when
connected by 15 ft. of field--supplied or factory--accessory tubing,

and factory supplied filter drier. Check refrigerant charge for
maximum efficiency.

Table 1—Refrigerant Connections and Recommended Liquid and Vapor Tube Diameters (In.)

UNIT SIZE

LIQUID

VAPOR

(up to 80 ft. *)

Connection

Diameter

Tube

Diameter

Connection

Diameter

Rated Tube

Diameter

018, 024

3/8

5/8

030, 036

3/8

3/4

042, 048

3/8

7/8

060

3/8

7/8

1--1/8

Notes:

1. Tube diameters are for total equivalent lengths up to 80 ft..

2. Do not apply capillary tube or fixed orifice indoor coils to these units.
* For Tubing Set lengths between 80 and 200 ft. horizontal or 20 ft. vertical differential (250 ft. Total Equivalent Length), refer to the Longline Guideline--- Air

Conditioners and Heat Pumps using Puron refrigerant.

Table 2—Accessory Usage

Accessory

REQUIRED FOR LOW---AMBIENT

APPLICATIONS

F To 55

)

REQUIRED FOR LONG LINE

APPLICATIONS* (Over 80 ft.)

Crankcase Heater

Yes

Evaporator Freeze Thermostat

Yes

(For non---Infinity systems only)

Winter Start Control

Yes

(For non---Infinity systems only)

Thermal Expansion Valve (TXV)

Hard Shutoff

Yes

Compressor Start Assist Capacitor and Relay

Yes

Low---ambient Pressure Switch

Yes

(For non---Infinity system only)

Support Feet

Recommended

Liquid Line Solenoid Valve

See Long---Line Application Guideline

* For Tubing Set lengths between 80 and 200 ft. horizontal or 20 ft. vertical differential (250 ft. Total Equivalent Length), refer to the Longline

Guideline --- Air Conditioners and Heat Pumps using Puron



refrigerant.

24AP

Install Liquid Line Filter Drier Indoor

CAUTION

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.

CAUTION

UNIT DAMAGE HAZARD

Failure to follow this caution may result in equipment

damage or improper operation.
Filter drier must be wrapped in a heat---sinking material

such as a wet cloth while brazing.

Refer to Fig. 5 and install filter drier as follows:

1. Braze 5--in. liquid tube to the indoor coil.
2. Wrap filter drier with damp cloth.
3. Braze filter drier to above 5” liquid tube. Flow arrow

must point towards indoor coil.

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

A05178

Fig. 5

---

Liquid Line Filter Drier

Refrigerant Tubing Connection Outdoor

Connect vapor tube to fitting on outdoor unit vapor service
valves (see Table 1.) Connect and braze the 3/8” coupling

(provided with the filter drier) to the liquid service valve and
connect and braze the liquid tubing to the other end of this

coupling. Use refrigerant grade tubing.

Sweat Connection

CAUTION

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

CAUTION

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.

Refrigerant tubes and indoor coil should be evacuated using the
recommended deep vacuum method of 500 microns. An alternate

triple evacuation method may be used if the deep vacuum

procedure is not followed.

IMPORTANT

: Always break a vacuum with dry nitrogen.

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. 6)

500

MINUTES

1000

1500

LEAK IN

SYSTEM

VACUUM TIGHT

TOO WET
TIGHT

DRY SYSTEM

2000

2500

3000

3500

4000

4500

5000

A95424

Fig. 6

---

Deep Vacuum Graph

24AP

Triple Evacuation Method

The triple evacuation method should be used when vacuum

pump is only capable of pumping down to 28 in. of mercury
vacuum and system does not contain any liquid water. Refer to

Fig. 7 and proceed as follows:

1. Pump system down to 28 in. of mercury and allow pump

to continue operating for an additional 15 minutes.

2. Close service valves and shut off vacuum pump.
3. Connect a nitrogen cylinder and regulator to system and

open until system pressure is 2 psig.

4. Close service valve and allow system to stand for 1 hr.

During this time, dry nitrogen will be able to diffuse

throughout the system absorbing moisture.

5. Repeat this procedure as indicated in Fig. 7. System will

then be free of any contaminants and water vapor.

CHECK FOR TIGHT, DRY SYSTEM

(IF IT HOLDS DEEP VACUUM)

EVACUATE

BREAK VACUUM WITH DRY NITROGEN

WAIT

EVACUATE

CHARGE SYSTEM

BREAK VACUUM WITH DRY NITROGEN

EVACUATE

WAIT

A95425

Fig. 7

---

Triple Evacuation Method

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.

STEP 7

—

Make Electrical Connections

WARNING

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.

WARNING

ELECTRICAL SHOCK HAZARD

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. 8.

DISCONNECT

PER N. E. C. AND/OR

LOCAL CODES

CONTACTOR

GROUND

LUG

FIELD GROUND

WIRING

FIELD POWER

WIRING

A91056

Fig. 8

---

Line Power Connections

24AP

Connect Control Wiring

Route 24--v control wires through control wiring grommet and

connect leads to control wiring. (See Fig. 13 & Fig. 14)
Use No. 18 AWG color--coded, insulated (35

C minimum) wire.

If thermostat is located more than 100 ft. 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.

STEP 8

—

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. Refer to the Longline

Guideline Section -- Residential Split--System Air Conditioners

and Heat Pumps Using Puron

Refrigerant.

STEP 9

—

Install Electrical Accessories

Refer to the individual instructions packaged with kits or

accessories when installing.

STEP 10

—

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. 9.

OAT Thermistor must be locked in place

with spherical nib end facing towards the front

of the control box

A06313

Fig. 9

---

Outdoor Air Thermistor (OAT) Attachment

The Outdoor Coil Temperature (OCT) Thermistor is factory

installed on the liquid tube between the coil assembly and the
liquid service valve. See Fig. 10.

Check to make sure the thermistor is securely attached on the
liquid tube with the clip as shown in Fig. 10.

OCT Thermistor must be

secured tight on the liquid tube.

A05409

Fig. 10

---

Outdoor Coil Thermistor (OCT) Attachment

STEP 11

—

Start--Up

CAUTION

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.

CAUTION

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.

CAUTION

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.

24AP

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. . Open fully by turning the stem

counter clockwise as far as it will go, and tighten lightly.
This opens the valve to refrigerant flow, and closes the

gage port. To leave gage port open, fully open the valve,
and then turn the stem clockwise a few turns. This will
allow pressure to be sensed without restricting refrigerant

flow.
Replace stem caps after system is opened to refrigerant

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

NOTE

: The gage port does not contain a Schrader core.

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.

STEP 12

—

Check Charge

Unit Charge

Factory charge and charging methods are shown on unit
information plate. Charge Puron refrigerant units with cylinder in

upright position and a commercial--type metering device in

manifold hose. Charge refrigerant into suction line.

NOTE

: If subcooling charging conditions are not favorable,

charge must be weighed in accordance with unit rating plate,

0.6

oz/ft. of 3/8--in. liquid line above or below 15 ft., respectively.
Favorable conditions fall within the ranges given on the charging
chart on the outdoor unit plate.

NOTE

: In longline applications, see Application Guideline for

special charging requirements.
EXAMPLE:
To calculate additional charge required for a 25 ft. line set:

25 ft. -- 15 ft. = 10 ft. X 0.6 oz/ft. = 6 oz. of additional charge.

Cooling Only Procedure

This system requires charging by the subcooling method.

1. Operate unit a minimum of 10 minutes before checking

charge.

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 Table 4. 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

Major Components
Control Board

The AC control board controls the following functions:

Compressor contactor operation

Outdoor fan motor operation

Compressor external protection

Pressure switch monitoring

Time Delays

Field Connections

When used with a standard 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. 15).
When only 2 thermostat control wires are available, units
beginning with serial numbers 3006E and newer will function,

but some control features are lost. (See Fig. 16). With only 2
wires connected, the circuit board will be powered down

whenever there is no call for cooling, and the following will

result:

Compressor time delay is reduced from 5 minutes to 10
seconds

When the thermostat is not calling for cooling, the amber
status light will be off, and no diagnostics codes will be

available

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

When using Infinity Communicating control, 4 wires are required

to be connected to the ABCD terminal (see Fig. 14)

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.

24AP

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
Infinity communication User Interface. 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 degrees F.

Communication and Status Function Lights
Green Communications (COMM) Light (Infinity 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 communication 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 3 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 degrees F.

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 degrees F.

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 (there

is no bypass of this feature in a non--communicating
system, in a communicating system push the UI fan and

up buttons simultaneously

for approximately 10

seconds)

When operating the unit with 2 wires, this delay is
shortened to 10 seconds.

Five minute compressor recycle delay on return from a
brown out condition

Two minute time delay to return to standby operation
from last valid communications (with Infinity only)

One minute time delay of outdoor fan at termination of
cooling mode when outdoor ambient is greater than or

equal to 100 deg F

Utility Interface
With Infinity Control

The input labeled UTIL is active only when a communicating

Infinity Control is used. This input allows a power utility device
to interrupt compressor operation during peak load periods. See

figure below for wiring connections. When the utility sends a

signal to shut the system down, the User Interface will display
”CURTAILMENT ACTIVE”.

INFINITY BOARD

UTILITY RELAY

UTILITY SIGNAL

OPEN RELAY

SUPPLIED BY UTILITY PROVIDER

UTIL

A05410

Fig. 11

---

Utility Interface

With Non--Communicating Thermostats

W h e n t h e u t i l i t y c u r t a i l m e n t i n t e r f a c e i s u s e d w i t h a
non--communicating thermostat, the utility relay should be wired

in series with the Y input.

Low Ambient Cooling

When this unit is required to operate below 55

F to a minimum

of 0

F outdoor temperature, provisions must be made for low

ambient operation.

Low ambient cooling operation can be accomplished two ways
depending on the control system:

Complete Infinity System

Standard non--communicating thermostat

Infinity Controlled low ambient cooling:

This unit is capable of low ambient cooling without a kit ONLY
when using a complete Infinity system. A low ambient kit is not

required, and the outdoor fan motor does not need to be replaced

for Infinity controlled low ambient operation. The Infinity
Control provides an automatic evaporator coil freeze protection

algorithm that eliminates the the need for an evaporator freeze
thermostat. Low ambient cooling must be enabled in the User

Interface set up. Fan may not begin to cycle until about 40

OAT. Fan will cycle based on coil and outdoor air temperature.
A crankcase heater

must

be installed. See Product Data for

accessory part numbers on appropriate unit size and series.
Infinity controlled low ambient mode operates as follows:

Fan is OFF when outdoor coil temp is < (outdoor air
temperature + 3

F) or outdoor fan has been ON for 30

minutes. (Fan is turned off to allow refrigerant system to

stabilize.)

Fan is ON when outdoor coil temp > (outdoor air
temperature + 25

F) or outdoor coil temp > 80

F or if

outdoor fan has been OFF for 30 minutes. (Fan is turned
on to allow refrigerant system to stabilize.)

Low pressure switch is ignored for first 3 minutes during
low ambient start up. After 3 minutes, if LPS trips, then
outdoor fan motor is turned off for 10 minutes, with the

compressor running. If LPS closes within 10 minutes
then cooling continues with the outdoor fan cycling per

the coil temperature routine listed above for the remainder
of the cooling cycle. If the LPS does not close within 10

minutes, then the normal LPS trip response (shut down
cooling operation and generate LPS trip error) will occur.

Standard Thermostat low ambient cooling mode:

The following optional accessories must be installed for low

ambient operation in standard thermostat mode:

Low Ambient Pressure Switch Kit

Evaporator Freeze Thermostat

Winter Start Control

Crankcase Heater

The fan motor is a ball bearing type and does not need to be
changed. A crankcase heater

must

be installed. See Product Data

for accessory part numbers on appropriate unit size and series
units.

TROUBLESHOOTING

SYSTEMS COMMUNICATION FAILURE

If communication between outdoor unit, control board, and
indoor user interface control has failed, the control will flash the

appropriate fault code. (See table 3) Check the wiring to the UI,

indoor and outdoor units.

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 de--energize the compressor

contactor, keep the outdoor fan operating for 15 minutes and
display the appropriate fault code. (See table 3)
After a 15 minute delay, if there is still a call for cooling, and the

LPS or HPS is reset, the compressor contactor is energized. If the

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 the unit will resume operation with a call
for cooling.
If the LPS or HPS trips for five consecutive cycles, then unit

operation is locked out for 4 hours and the appropriate fault code

(See table 3) is displayed.
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.
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 3) The control board should
be replaced.

24V BROWN OUT PROTECTION

If the control voltage is less than 15.5volts for at least 4 seconds,
the compressor contactor and fan relay are de--energized.

Compressor and fan operation are not allowed until control
voltage is a minimum of 17.5volts. The control will flash the

appropriate fault code. (See table 3) Verify the control voltage is

in the allowable range of 18--30volts.

COMPRESSOR VOLTAGE SENSING

The input terminals labeled VR and VS on the control board (see

Fig. 13) 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.

COMPRESSOR THERMAL CUTOUT OR LOSS OF 230V
POWER

If the control senses the compressor voltage after start--up, and is

then absent for 10 consecutive seconds while cooling demand

exists, it will de--energize the compressor contactor, keep the
outdoor fan operating for 15 minutes (if 230v power present) and

display the appropriate fault code. (See table 3) Possible causes
are compressor internal overload trip or loss of high voltage

(230V) to compressor without loss of control voltage.
After a 15 minute delay, if there is still a call for cooling, the

compressor contactor is energized. If the thermal protector has
not re--set, 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
(See Table 3) 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 3)

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

≥

F warmer than the coil sensor (or) the

outdoor air sensor indicates

≥

F 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. (See Table 3)
The thermistor comparison is not performed during low ambient
cooling.

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.
Thermistor Curve: The resistance vs. temperature chart shown in
Figure 12 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

60ºF, the resistance reading across the outdoor air thermistor
should be around 16,000 Ohms.

163A

/165A
24AP

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 3 gives possible causes and actions

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

Table 3— Status Codes

OPERATION

FAULT

AMBER LED

FLASH CODE

Possible Cause and Action

Standby – no

call for unit

operation

None

On solid, no flash

Normal operation --- 3 thermostat wires or 4 wire Infinity Control

Standby – no

call for unit

operation

None

Off

Normal operation --- No call for cooling with 2---wire connection or indoor

unit not powered.

Cooling

Operation

None

1, pause

Normal operation

System Communica-

tions Failure

Communication with user interface lost. Check wiring to UI, indoor and

outdoor units

High Pressure

Switch Open

High pressure switch trip. Check refrigerant charge, outdoor fan opera-

tion and coils for airflow restrictions.

Low Pressure

Switch Open

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

Control Fault

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

replaced.

Brown Out

(24 v)

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.

Outdoor Air Temp

Sensor Fault

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

check wiring

Outdoor Coil Sensor

Fault

Coil sensor not reading or out of range. Ohm out sensor and check wiring

Thermistors out

of range

Improper relationship between coil sensor and outdoor air sensor. Ohm

out sensors and check wiring.

Thermal Cutout

Compressor voltage sensed after start---up, then absent for 10 consecu-

tive 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.

Contactor Shorted

Compressor voltage sensed when no demand for compressor operation

exists. Contactor may be stuck closed or there is a wiring error.

No 230V at

Compressor

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 Lockout

Thermal cutout occurs in three consecutive cycles. Unit operation locked

out for 4 hours or until 24v power recycled.

Low Pressure Lockout

Low pressure switch trip has occurred during 5 consecutive cycles. Unit

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

High Pressure

Lockout

High pressure switch trip has occurred during 5 consecutive cycles. Unit

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

24AP

100

120

TEMPERATURE (DEG. F)

RESISTANCE (KOHMS)

THERMISTOR CURVE

A91431

Fig. 12

---

Resistance vs Temperature Chart

Outdoor Coil Temp (OCT)

}

Outdoor Air Temp (OAT)

}

COMM STATUS

A06314

Fig. 13

---

Single--Stage Control Board

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.

5. Fill out

Dealer Installation Checklist and place in

customer file.

CARE AND MAINTENANCE

For continuing high performance and to minimize possible

equipment failure, 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.

24AP

Table 4—Required Liquid---Line Temperature (

LIQUID

PRESSURE

AT SER-

VICE VALVE

(PSIG)

REQUIRED SUBCOOLING TEMPERATURE (

189

195

202

208

215

222

229

236

243

251

259

266

274

283

291

299

308

317

326

335

345

354

100

364

102

100

374

104

102

100

384

106

104

102

100

395

108

106

104

102

100

406

110

108

106

104

102

100

416

112

110

108

106

104

102

427

114

112

110

108

106

104

439

116

114

112

110

108

106

450

118

116

114

112

110

108

462

120

118

116

114

112

110

474

122

120

118

116

114

112

486

124

122

120

118

116

114

499

126

124

122

120

118

116

511

128

126

124

122

120

118

24AP

Single Stage AC

A06087

Fig. 14

---

Infinity Control Four--Wire Connection Wiring Diagrams

(See Thermostat Installation Instructions for specific unit combinations)

A06305

LEGEND

24--V FACTORY WIRING

24--V FIELD WIRING

FIELD SPLICE CONNECTION

A97368

Fig. 15

---

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

(See Thermostat Installation Instructions for Specific Unit combinations)

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.

CAUTION

24AP

W/W1

Y/Y2

24VAC HOT

24VAC COM

INDOOR FAN

A/C THERMOSTAT

TYPICAL FURNACE

FAN COIL

AIR CONDITIONER

A/C THERMOSTAT

AIR CONDITIONER

COOL STAGE 1

HEAT STAGE 1

FIELD INSTALLED

JUMPER WIRE

A06304

Fig. 16

---

Non--Communicating Standard Thermostat

2--Wire 24V Circuit Connections

(Applicable to units beginning with serial nuumber 3006E and newer)

NOTE

: Wiring must conform to NEC or local codes.

PURON

(R--410A) REFRIGERANT QUICK REFERENCE GUIDE

Puron refrigerant operates at 50--70 percent higher pressures than R--22. Be sure that servicing equipment and replacement

components are designed to operate with Puron refrigerant.

Puron refrigerant cylinders are rose colored.

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

Puron refrigerant 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 700 psig high side and 180 psig low side with 550 psig low--side retard.

Use hoses with 700 psig service pressure rating.

Leak detectors should be designed to detect HFC refrigerant.

Puron refrigerant, as with other HFCs, 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 leave Puron refrigerant suction line filter driers in line longer than 72 hours.

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 factory approved liquid--line filter drier is required on every unit.

Do NOT use an R--22 TXV.

If indoor unit is equipped with an R--22 TXV or piston metering device, it must be changed to a hard shutoff Puron TXV.

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

When system must be opened for service, recover refrigerant, evacuate then break vacuum with dry nitrogen and replace filter driers.

Evacuate to 500 microns prior to recharging.

Do not vent Puron refrigerant into the atmosphere.

Do not use capillary tube coils.

Observe all

warnings

cautions

, and

bold

text.

All indoor coils must be installed with a hard shutoff Puron TXV metering device.

24AP

7310 W. Morris St.

Indianapolis, IN 46231

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

Catalog No: 24APA--3SI

Replaces: 24APA--2SI

Printed in U.S.A.

Edition Date: 06/ 06

24AP