Carrier 48HJD005-007 specifications MoistureMiser Dehumidification Subcooler Service Analysis

Models: 48HJD005-007

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Table 35 — MoistureMiser Dehumidification Subcooler Service Analysis

PROBLEM

CAUSE

 

REMEDY

Subcooler will not energize.

No power to control transformer from

Check power source and evaporator-fan relay. Ensure

 

evaporator-fan motor.

all wire connections are tight.

 

No power from control transformer to liquid line

1.

Fuse open; check fuse. Ensure continuity of wiring.

 

solenoid valve

2.

Low-pressure switch open. Cycle unit off and allow

 

 

 

low-pressure switch to reset. Replace switch if it will

 

 

 

not close.

 

 

3. Transformer bad; check transformer.

 

Liquid line solenoid valve will not operate.

1.

Solenoid coil defective; replace.

 

 

2.

Solenoid valve stuck open; replace.

Subcooler will not deenergize.

Liquid line solenoid valve will not open.

Valve is stuck closed; replace valve.

Low system capacity.

Low refrigerant charge or frosted evaporator

1.

Check charge amount. Charge per Fig. 47-51.

 

coil.

2.

Evaporator coil frosted; check and replace low-

 

 

 

pressure switch if necessary.

Loss of compressor superheat

Thermostatic expansion valve (TXV).

1.

Check TXV bulb mounting, and secure tightly to

conditions with subcooler

 

 

suction line.

energized.

 

2.

Replace TXV if stuck open or closed.

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Carrier 48HJD005-007 specifications MoistureMiser Dehumidification Subcooler Service Analysis