Carrier Air Conditioner 38CKB User Manual

38CKB—50 Hz

Air Conditioning Unit

Installation and Start-Up Instructions

NOTE: Read the entire instruction manual before starting the

installation.

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 thor-

oughly and follow all warnings or cautions included in literature

and attached to the unit. Consult local building codes and national

electric codes for special requirements.

A94356

Fig. 1—Model 38CKB

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.

For proper airflow, a 6-in. (152mm) clearance on 1 side of unit and

12 in. (305mm) on all remaining sides must be maintained.

Maintain a distance of 24 in. (610mm) between air conditioners.

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

directly on unit.

Understand the signal word DANGER, WARNING, or CAU-

TION. These words are used with the safety-alert symbol. DAN-

GER 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.

On rooftop applications, locate unit 6 in. (152mm) above roof

surface. Where possible, place unit above a load-bearing wall.

Arrange supporting members to adequately support unit and

minimize transmission of vibration to building. Consult local

codes governing rooftop applications.

Before installing, modifying, or servicing system, main elec-

trical 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. Electrical shock can

cause personal injury or death.

Step 3—Replace Indoor AccuRater® Piston, if Required

Check indoor coil piston to see if it matches the required piston

shown on unit rating label. If it does not match, replace indoor coil

piston with piston shipped with this unit. The piston shipped with

outdoor unit is correct for any approved indoor coil combination.

INSTALLATION

Step 1—Check Equipment and Jobsite

UNPACK UNIT — Move to final location. Remove carton taking

care not to damage unit.

Remove indoor coil piston if unit is to be installed on system

with a TXV metering device.

INSPECT EQUIPMENT — File claim with shipping company

prior to installation if shipment is damaged or incomplete. Locate

unit rating label on unit service panel. (See Fig. 2.) It contains

information needed to properly install unit. Check rating label to

be sure unit matches job specifications.

Step 4—Make Piping Connections

Outdoor units may be connected to indoor sections using accessory

tubing package or field-supplied refrigerant grade tubing of correct

size and condition. For tubing requirements beyond 50 ft (15.24m),

consult Long-Line Application Guideline which is available at

your local distributor.

Step 2—Install on a Solid, Level Mounting Pad

If conditions or local codes require the unit be attached to pad,

tiedown bolts should be used and fastened through knockouts

provided in unit base pan. Refer to unit mounting pattern in Fig. 2

to determine base pan size and knockout hole location.

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

gas pulsations from improper installation of equipment.

INSTALLATION RECOMMENDATIONS

1. Locate the unit away from windows.

When installing, allow sufficient space for airflow clearance,

wiring, refrigerant piping, and service. Allow 30-in. (762mm)

clearance to service end of unit and 48 in. (1219mm) above unit.

2. Ensure that vapor and liquid tube diameters are appropriate to

the capacity of the unit. (See Table 1.)

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

Book

Tab 3a 2a

PC 101

Catalog No. 013-862

Printed in U.S.A.

Form 38CKB-C1SI

Pg 1

12-94

Replaces: New

Table 1—Refrigerant Connections and Recommended Liquid and Vapor Tube Diameters

LIQUID

VAPOR

UNIT SIZE

Connection Dia.

In. mm

Tube Dia.

Connection Dia.

Tube Dia.

In.

3/8

In.

5/8

018, 024

036

3/8

9.53

5/8

3/4

7/8

15.88

19.05

22.23

15.88

19.05

22.23

28.58

3/4

048

7/8

060

1-1/8

1. Tube diameters are for lengths up to 50 ft (15.24m). For tube sets over 50 ft (15.24m), consult Long-Line Application Guideline.

2. Do not apply capillary tube indoor coils to these units.

NOTE: Operation of unit on improper line voltage constitutes

abuse and could affect unit reliability. See unit rating label. Do not

install unit in system where voltage or phase imbalance may

fluctuate above or below permissible limits.

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.

NOTE: Use copper wire only between disconnect switch and

unit.

NOTE: Install branch circuit disconnect per local codes of

adequate size to handle unit starting current. Locate disconnect

within sight from and readily accessible from unit per local codes.

SWEAT CONNECTION — Use refrigerant grade tubing. Service

valves are closed from factory and ready for brazing. After

wrapping the service valve with a wet cloth, the tubing set can be

brazed to the service valve using either silver bearing or non-silver

bearing brazing material. Consult local code requirements. Refrig-

erant tubing and indoor coil are now ready for leak testing. This

check should include all field and factory joints.

To avoid personal injury or death, do not supply power to unit

with compressor terminal box cover removed.

NOTE: Avoid contact between tubing and structure.

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. Failure to follow this warning can result in an

electric shock, fire, or death.

OUTDOOR WALL

CAULK

INDOOR WALL

LIQUID TUBE

ROUTE GROUND AND POWER WIRES — Remove access

panel and control box cover to gain access to unit wiring. Extend

wires from disconnect through power wiring hole provided and

into unit control box. (See Fig. 2.) Size wires per local codes, but

not smaller than minimum wire size shown on unit rating label.

VAPOR TUBE

JOIST

INSULATION

THROUGH THE WALL

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. 4.

HANGER STRAP

(AROUND VAPOR

TUBE ONLY)

INSULATION

VAPOR TUBE

DISCONNECT

PER N.E.C. AND/OR

LOCAL CODES

CONTACTOR

FIELD POWER

WIRING

1″ MIN

(25 mm)

LIQUID TUBE

BLUE

3 PHASE ONLY

SUSPENSION

FIELD GROUND

WIRING

A94330

Fig. 3—Piping Installation

GROUND

LUG

A94025

Fig. 4—Line Power Connections

Step 5—Make Electrical Connections

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 label. Contact local power company for correction of

improper voltage. See unit rating label for recommended circuit

protection device.

NOTE: Use No. 18 AWG (American Wire Gage) color-coded,

insulated (35° C minimum) wire. If thermostat is located more than

100 ft (30.5m) from unit as measured along the control voltage

wires, use No. 16 AWG color-coded wires to avoid excessive

voltage drop.

CONNECT CONTROL WIRING — Route 24-v control wires

through control wiring grommet and connect to brown and blue

pigtails supplied in unit splice box. (See Fig. 5.)

Do not vent refrigerant to atmosphere. Recover during system

repair or final unit disposal.

Use furnace transformer, fan-coil transformer, or accessory trans-

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

1. Fully back seat (open) liquid and vapor tube service valves.

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

mum 40-va power requirement. Determine total transformer load-

ing and increase the transformer capacity or split the load with an

accessory transformer as required.

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

installed. Replace stem caps after system is opened to refrig-

erant flow (back seated). Replace caps finger-tight and tighten

additional 1/6 turn with wrench.

Step 6—Compressor Crankcase Heat

3. Close electrical disconnects to energize system.

When equipped with a crankcase heater, energize heater a mini-

mum of 24 hrs before starting unit. To energize heater only, set

thermostat to OFF position and close electrical disconnect to

outdoor unit.

A crankcase heater is required if the refrigerant tubing is longer

than 50 ft (15.24m).

4. Set room thermostat at desired temperature. Be sure set point

is below indoor ambient temperature.

5. Set room thermostat at COOL and fan switch at FAN or

AUTO, as desired. Operate unit for 15 minutes. Check system

refrigerant charge.

Step 7—Install Electrical Accessories, If Any

6. Factory charge is shown on unit rating label. Adjust charge by

following procedure shown on charging tables located on unit.

Refer to the individual instructions packaged with the kit or

accessory when installing.

Step 9—Leave User’s Manual with Owner

Step 8—Start-Up and Check Charge

For continued high performance and to minimize possible equip-

ment failure, periodic maintenance MUST be performed on this

equipment.

Leave User’s Manual with owner. Explain system operation and

periodic maintenance requirements outlined in manual. Frequency

of maintenance may vary depending on geographic areas, such as

coastal applications which require more frequent maintenance.

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.

• In 3 phase application, incorrect phasing will cause reverse

rotation, resulting in elevated noise levels, equalized pres-

sures and reduced current draw. Correct by reversing power

connection L1 and L2 on contactor.

To prevent personal injury wear safety glasses, protective

clothing, and gloves when handling refrigerant and observe

the following:

• Back seating service valves are not equipped with Schrader

valves. Fully back seat (counter clockwise) valve stem before

removing gage port cap.

• Front seating service valves are equipped with Schrader

valves.

THERMOSTAT

FURNACE

MOTOR

POWER

SUPPLY

IFR

TRANS

COOLING ONLY

FAN COIL

ONE STAGE COOLING / GAS HEATING

THERMOSTAT

INDOOR UNIT

LLS

ONE STAGE COOLING / ELECTRIC HEAT

ONE STAGE COOLING / HEATING

ACCESSORY LIQUID LINE SOLENOID

NOTES:

1. Wiring must conform to local codes.

2. LLS required on some units. See specific unit instructions.

3. Transformer required is 24-v, 40-va minimum. A 60-va or external power source may

be necessary when installing accessories.

4. When installing electronic thermostat, connect transformer common to thermostat C.

LEGEND:

– COMPRESSOR CONTACTOR

– INDOOR FAN MOTOR

LLS – LIQUID LINE SOLENOID

TRANS – TRANSFORMER

IFR – INDOOR FAN RELAY

A94331

Fig. 5—24-v Control Circuit Connections

38ckbc1s