Carrier 38CMC User Manual

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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 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 the signal words DANGER, WARNING, and CAUTION. These words are used with the safety-alert symbol. DANGER identifies the most serious hazards which willresultinsevere 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.

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. Electrical shock can cause personal injury or death.

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.

2. Ensure that vapor and liquid tube diameters are appropriate to capacity of unit. (See Model Specific Instructions for proper tube sizing.)

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, ductwork, floor joists, wall studs, floors, and walls.

38CKC(Q), 38CMC, 38BRC

Split-System Air Conditioner

A97005

Fig. 1—Split-System Air Conditioner

7. Do not suspend refrigerant tubing from joists and studs with a rigid wire or strap which comes in direct contact with the 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.

When outdoor unit is connected to factory-approved indoor unit, outdoor unit contains system refrigerant charge for operation with factory-approved indoor unit of the same size when connected by 15 ft of field-supplied tubing. For proper unit operation, check refrigerant charge using charging information located on control box cover.

INSTALLATION

Step 1—Check Equipment and Jobsite

INSPECT EQUIPMENT — If shipment is damaged or incomplete, file claim with shipping company prior to installation. Locate unit rating plate on unit service 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, use tiedown bolts to fasten through knockouts provided in unit base pan. Refer to Fig. 3 for pad dimensions and dimensions needed to mount unit to pad.

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

Book 1 4 Tab 3a 2a

PC 101 Catalog No. 533-840 Printed in U.S.A. Form 38BRC-1SI Pg 1 2-97 Replaces: New

Avoid contact between tubing and structureNOTE:

OUTDOOR WALL INDOOR WALL

CAULK

INSULATION

THROUGH THE WALL

HANGER STRAP

(AROUND VAPOR

TUBE ONLY)

1″ MIN.

SUSPENSION

LIQUID TUBE

VAPOR TUBE

JOIST

INSULATION

VAPOR TUBE

LIQUID TUBE

A94028

Fig. 2—Connecting Tubing Installation

Step 3—Clearance Requirements

When installing, allow sufficient space for airflow clearance, wiring, refrigerant piping, and service. Common clearances are 6 in. on 1 side, 12 in. on 2 sides, and 30 in. on service side of unit. Allow 24 in. between units. Discharge air must be unobstructed and must not recirculate.

Position so water, snow, or ice from roof or eaves cannot fall directly on unit.

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

Step 4—Operating Ambients

The minimum outdoor operating ambient in cooling mode is 55°F, and the maximum outdoor operating ambient in cooling mode is 125°F.

Step 5—Metering Device

If unit is being installed withpiston,check indoor coil piston to see if it matches the required piston shown on outdoor unit rating plate. If it does not match, replace indoor coil piston with piston shipped with outdoor unit. The piston shipped with outdoor unit is correct for any approved indoor coil combination.

⁄8″D. (9.53) TIEDOWN 

KNOCKOUTS (2) PLACES 

TIEDOWN KNOCKOUT

UNIT SIZE

38CKC(Q)018, 024 18 X 18 3 15 10-3/16

38CKC(Q)030-042

38CMC018-030 38BRC024-060

38CKC(Q)048, 060

38CMC036-060

MIN PAD DIM (IN.)

22-1/2 X 22-1/2 3-11/16 18-1/8 14-3/8

30 X 30 6-1/2 23-1/2 20

LOCATIONS

(In.)

Fig. 3—Mount Unit to Pad

Step 6—Make Tubing Connections

Relieve pressure and recover all refrigerant before system repair or final unit disposal to avoid personal injury or death. Use all service ports and open all flow-control devices, including solenoid valves.

To prevent compressor damage DO NOT bury more than 36 in. of refrigerant tubing. If ANY tubing is buried, provide 6 in. vertical rise at service valve.

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.

Connect outdoor unit to indoor sections using accessory tubing package or field-supplied tubing of refrigerant grade, correct size, and condition. Refer to Fig. 4 for refrigerant tube dimensions and connections. For tubing requirements beyond 50 ft, consult your local distributor or the Long-Line Application Guideline.

SWEAT CONNECTION

1. Consult local code requirements.

2. Connect tubing to fittings on outdoor unit vapor and liquid service valves.

3. Service valves are closed from factory and ready for brazing.

A94199

(In.)

AIR DISCHARGE

FIELD POWER  SUPPLY CONN

⁄8″ DIA HOLE WITH  1 1⁄8″ DIA KNOCKOUT AND

1 3⁄8″ DIA

KNOCKOUT

FIELD CONTROL  SUPPLY CONN

SUCTION LINE CONN

LIQUID LINE CONN

UNIT SIZE

018, 024 3/8 3/8 5/8 5/8 030, 036 3/8 3/8 3/4 3/4 042, 048 3/8 3/8 7/8 7/8

060 3/8 3/8 7/8 1-1/8

NOTE: Tube diameters are for lengths up to 50 ft. For tubing lengths greater than 50 ft, consult your local distributor.

LIQUID TUBE VAPOR TUBE

Conn Dia Tube Dia Conn Dia Tube Dia

⁄8″ DIA HOLE 

A97009

If refrigerant tubing or indoor coil is exposed to atmosphere, it must be evacuated to a minimum of 500 microns to eliminate contamination and moisture in the system.

Fig. 4—Refrigerant Tube Dimensions/Connections

If undersized, damaged, or elliptically shaped tubing is used when making connection, leaks could result.

3. Slide lock nut and ferrule onto each tube. (See Fig. 6.)

FERRULE LOCK NUT

TUBING

A92121

Fig. 6—Lock Nut/Ferrule Positioning (38CKQ)

4. Apply a few drops of refrigerant oil to ferrule and valve threads to reduce assembly torque and assist sealing.

5. Insert tube end into service valve until it bottoms.

6. Push ferrule into place and hand tighten nut until an increase in torque is felt.

7. Mark nut and tube and tighten 1-1/2 turns from mark. (See Fig. 7.) Keep tube bottomed in valve while tightening nut.

NOTE: A backup wrench on the hex part of the suction valve is required while tightening.

4. After wrapping service valve with a wet cloth, tubing set can be brazed to service valve using either silver bearing or non-silver bearing brazing material.

5. Refrigerant tubing and indoor coil are now read for leak testing. This check should include all field and factory joints.

MECHANICAL CONNECTION (38CKQ MODELS)

1. Cut tubing to correct length, deburr, and size as necessary, making sure tube ends are square. If a large burr is evident, ID and OD must be deburred to allow tube to bottom in valve.

2. Remove lock nuts and ferrules from plastic bags taped to service panel. (See Fig. 5.)

VALVE FITTING

FERRULE

LOCK NUT

A92120

Fig. 5—Mechanical Fitting Assembly (38CKQ)

The tube end must stay bottomed in the service valve during final assembly to ensure proper seating, sealing, and rigidity.

MECHANICAL FITTING REPAIR To replace damaged ferrule or tubing proceed as follows.

1. Attach gages to service valves.

2. Close liquid service valve and operate unit to pump refrigerant charge into condenser coil.

3. When suction pressure reaches 5 psig, shut unit off. Do not operate unit in a vacuum.

4. Close suction service valve and recover refrigerant in tubing.

5. Back-off locknut and ferrule onto tube.

6. Remove damaged part of tubing using tubing cutter. Repeat installation procedure previously outlined using new ferrule.

7. Evacuate tubing set and indoor coil. Check for leaks.

8. Open service valves or recharge unit. Check refrigerant charge.

Step 7—Install Solenoid Valve In Liquid Tube (If Required)

Not all applications require use of a liquid tube solenoid valve. If your unit has been shipped with a liquid tube solenoid valve in the unit, it must be installed for performance enhancement. The liquid tube solenoid valve must be energized during evacuation for complete removal of refrigerant.

Before making liquid tube connections, install factory-supplied solenoid valve on indoor liquid fitting. (See Fig. 8.) Be sure to use flare adapter supplied with the indoor coil when making connections.

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