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Overload of electric motor
Analysis of Trouble
Probably, too many things have been put into the refrigerator, and hence the thermal load
exceeds its refrigerating capacity; or in case the power supply voltage drops considerably,
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.
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.
Sudden stoppage due to other causes.
Normal Stoppage
Thermostat generally controls start and stop of the compressor. 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 problem; care should be taken to
differentiate it from other real problems in servicing.
Compressor won 't start.
In case the compressor cannot be started, you must find out the origins of this trouble
through systematic checkup, because probably there are many causes, including the
electrical and mechanical parts.
a) 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, find out its real cause and take corrective
measures to resolve the problem.
Remedy
i) Check the input power circuit to see whether there is voltage in the power supply,
note:
the circuit that is connected to the knife switch. This can be determined with a
voltmeter 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.
