refrigerating effect. Furthermore, the gas discharge pressure will exceed its normal value when the
compressor has run for a period not too long, thus making the protective relay actuate and bring to a
stoppage.
REMEDY
Check up how the air has been left in the refrigerating system. Generally, there are two possibilities:
one is that the air has been sucked into the system when repairing due to carelessness, or it has not
been purged out totally when evacuating the system; the other is that there are leak points at the low
pressure end of the refrigerating system. Leak points appear mostly in those low temperature parts or
assemblies, because the evaporation temperature is lower for such low temperature devices,
especially at the low pressure end, it is easier for the air goes into the system. Once it has been
ascertained that air does exist in the system, you have to open the tubing, re-evacuate it and then
charge it with refrigerant.
2) Stoppage due to electric troubles
a) Thermostat is out of control
ANALYSIS OF TROUBLE
In case the thermostat does not work in its good order or its temperature sensor has not been installed
properly, frequent stoppage is also likely to occur.
REMEDY
Try to adjust the temperature sensor’s position until the compressor can be started and stopped
normally. If this cannot be achieved, and the stoppage still occurs repeatedly, it is most likely that the
mechanical parts or contacts are out of order, disassemble the thermostat, make a thorough checkup
and repair it.
b) 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.
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
