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the current flowing through the motor will increase drastically making the thermal protector
actuate and the fuse blown , and hence the motor stops running. If the motor is still running
continuously in such a case , its windings will be burned out .
Remedy
Reduce the thermal load, pay attention to the variation in voltage of the power supply.
c) Abnormal thermal protection.
Analysis of Trouble
The compressor current is within its normal range, but the thermal protector actuates
repeatedly.
Remedy
Replace the thermal protector with a new one.
3) Sudden stoppage due to other causes
Normal Stoppage
Start and stop of the compressor is generally controlled by a thermostat . When the
temperature in the refrigerator reaches its desired value, the thermostat will shut down the
compressor automatically. Never take this normal operation as a trouble, care should be
taken to differentiate it from other real troubles in servicing.
D. Compressor won 't start
In case the compressor cannot be started, you must find out the origins of this trouble
through checkup step by step, because probably there are many causes, including those
electrical and mechanical.
1) Inspect the power supply to see whether it is connected to the compressor circuit.
Analysis of Trouble
In case the compressor cannot be started, this will generally exhibit in the power supply
circuit, for instance, power failure, poor contact of switch, and blown fuse. Make a
comprehensive analysis of these phenomena, fine out its real cause and take correct
measures to remove this trouble.
Remedy
a) Check the input power circuit to see whether where is voltage of the power supply,
namely, the circuit which is connected to the knife switch. This can be determined with an
avometer or a test pencil. If a blown fuse is found, ascertain and remove its cause, then
replace it with a new one of the same specifications.
b) Check the compressor accessories, including its thermal protector and relay. In case the
thermal protector is damaged, the compressor cannot be powered on. If the relay is out of
order, the motor will not run and hum sound can be heard from it after the compressor is
turned on, in that case, shut it down immediately, otherwise, the motor windings will be
burned out in case this condition lasts longer.
c) Check the relay contacts and plugs to see if they are perfect and work reliably. Poor
contact may cause the motor not running or humming.
2) Check the circuit voltage to see whether it is normal.
Analysis of trouble
If the circuit voltage is obviously lower than its rated value, it will be difficult to start the
motor, and a hum sound can be heard from it.
Remedy
