Table 1 – Cooling Service Analysis

PROBLEM

CAUSE

REMEDY

 

Power failure.

Call power company.

 

 

 

 

Fuse blown or circuit breaker tripped.

Replace fuse or reset circuit breaker.

 

 

 

Compressor and Condenser

Defective thermostat, contactor, transformer,

Replace component.

or control relay.

Fan Will Not Start.

 

 

 

Insufficient line voltage.

Determine cause and correct.

 

 

 

 

 

Incorrect or faulty wiring.

Check wiring diagram and rewire correctly.

 

 

 

 

Thermostat setting too high.

Lower thermostat setting below room temperature.

 

Faulty wiring or loose connections in

Check wiring and repair or replace.

 

compressor circuit.

 

 

 

 

 

 

Compressor motor burned out, seized, or

Determine cause. Replace compressor.

Compressor Will Not Start But

internal overload open.

 

Condenser Fan Runs.

 

 

Defective run/start capacitor, overload, start

Determine cause and replace.

 

relay.

 

 

 

 

 

 

One leg of three---phase power dead.

Replace fuse or reset circuit breaker. Determine

 

cause.

 

 

 

 

 

 

Refrigerant overcharge or undercharge.

Recover refrigerant, evacuate system, and recharge

 

to nameplate.

 

 

 

 

 

 

Defective compressor.

Replace and determine cause.

 

 

 

Compressor Cycles (other

Insufficient line voltage.

Determine cause and correct.

 

 

Blocked condenser.

Determine cause and correct.

than normally satisfying ther-

 

 

Defective run/start capacitor, overload, or start

 

mostat).

Determine cause and replace.

relay.

 

 

 

 

 

 

Defective thermostat.

Replace thermostat.

 

 

 

 

Faulty condenser---fan motor or capacitor.

Replace.

 

 

 

 

Restriction in refrigerant system.

Locate restriction and remove.

 

Dirty air filter.

Replace filter.

 

 

 

 

Unit undersized for load.

Decrease load or increase unit size.

 

 

 

Compressor Operates

Thermostat set too low.

Reset thermostat.

 

 

Low refrigerant charge.

Locate leak; repair and recharge.

Continuously.

 

 

Leaking valves in compressor.

Replace compressor.

 

 

Air in system.

Recover refrigerant, evacuate system, and recharge.

 

 

 

 

Condenser coil dirty or restricted.

Clean coil or remove restriction.

 

 

 

 

Dirty air filter.

Replace filter.

 

Dirty condenser coil.

Clean coil.

Excessive Head Pressure.

 

 

Refrigerant overcharged.

Recover excess refrigerant.

 

 

 

 

Air in system.

Recover refrigerant, evacuate system, and recharge.

 

Condenser air restricted or air short---cycling.

Determine cause and correct.

 

 

 

 

Low refrigerant charge.

Check for leaks; repair and recharge.

Head Pressure Too Low.

 

 

Compressor valves leaking.

Replace compressor.

 

 

 

 

Restriction in liquid tube.

Remove restriction.

 

 

 

 

High head load.

Check for source and eliminate.

Excessive Suction Pressure.

 

 

Compressor valves leaking.

Replace compressor.

 

 

 

 

Refrigerant overcharged.

Recover excess refrigerant.

 

 

 

 

Dirty air filter.

Replace filter.

 

Low refrigerant charge.

Check for leaks; repair and recharge.

 

 

 

 

Metering device or low side restricted.

Remove source of restriction.

Suction Pressure Too Low.

 

 

Insufficient evaporator airflow.

Increase air quantity. Check filter and replace if

 

necessary.

 

 

 

 

 

 

Temperature too low in conditioned area.

Reset thermostat.

 

 

 

 

Outdoor ambient below 25˚F.

Install low---ambient kit.

 

 

 

Evaporator Fan Will Not Shut

Time off delay not finished.

Wait for 30---second off delay.

Off.

 

 

 

 

 

Compressor Makes Excessive

Compressor rotating in wrong direction.

Reverse the 3---phase power leads.

Noise.

 

 

 

 

 

48TC

13

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Carrier 48TCA04---A12 appendix Cooling Service Analysis, Problem Cause Remedy
Page 12 Page 14

48TCA04---A12 specifications

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