Fault

Cause

Check/Correcitve Action

 

 

 

 

Discharge pressure is lower than standard.

See "Low Discharge Pressure".

 

 

 

 

Single or three phases running.

Check the power supply line and the

 

 

contactor.

 

 

 

 

High or low voltage or phase unbalance.

Check the voltage and phase unbalance.

 

 

 

Internal

Refrigerant short charge or leakage.

Add refrigerant, repair leakage, if any.

Thermostat

 

 

Cut-Off

 

 

Compressor frequently stops and starts.

Check thermistor operation, or any other

 

 

 

cause for frequent stop and start operation.

 

 

 

 

Discharge and suction pressure are

See "High Discharge Pressure" or "High

 

extremely high.

Suction Pressure".

 

 

 

Overcurrent

High or low voltage, or phase unbalance.

Check the voltage and phase unbalance.

 

 

Relay for

Single or three phases running

Check the power supply line and the

Compressor

 

contact.

Cut-Off

 

 

 

Faulty compressor motor.

Check electric resistance among the

 

 

 

compressor terminals, and from the

 

 

terminals to ground.

 

 

 

 

Loose connections.

Check the electric connections.

 

 

 

 

Compressor frequently stops and starts.

Check the operation of the thermistor, or

 

 

any other cause for frequent stop.

 

 

 

Overcurrent

High or low voltage, or phase unbalance.

Check the voltage and electric wiring.

 

 

Relay for

Single or three phases running.

Check the power supply line and the

Fan Motor

 

contactor.

Cut-Off

 

 

Faulty fan motor.

Check the fan motor and wiring.

 

 

 

 

 

Loose connection.

Check the elelctric connections.

 

 

 

 

Faulty fan bearing.

Check repair or replace the bearing.

 

 

 

 

Loose connections.

Check the electric connections.

Fuse Blown

 

 

Single or three phase running.

Check the power supply line.

 

 

 

 

 

Faulty motor.

Check electric resistance among motor

 

 

housing, and from the terminals to

 

 

ground.

 

 

 

Disconnection

Disconnection.

1. Check the wires and connect where

and Faulty

 

necessary.

 

2. Check the contact holding coil.

Contact

 

 

 

 

 

 

 

Faulty contact.

Check the contact in the magnetic

 

 

contact, the over-current relay, the

 

 

pressure control switch, the operation

 

 

switch, the auxiliary relay.

 

 

 

–33–

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Image 33
LG Electronics LF300CP(LP-C303R20), LF480CE(LP-C483TA0) service manual Cause for frequent stop and start operation