SERVICE MANUAL
Model:HRF-660S
35
Issue 201001
Rev.
Ref1001S008V0
8-3-4 Compressor could not be 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
Measure the voltage with a voltmeter, if it is really too low, give directions to the user for buying a
stabilizer so as to step up the voltage, thus normal operation can be achieved.
3) Check the thermal relay to see whether its contacts are closed.
Analysis of Trouble
The contacts of thermal relay sometimes may be open due to the leakage of temperature sensing
agent from the temperature sensor.
Remedy
Remove the relay cover to check up its contacts, if they are open, this means that the original setting
is not properly set or temperature sensing agent has leaked out of the temperature sensor. Try to turn
the adjusting stem of this value in the direction of the lower temperature graduation, and then check
the contacts to see whether they are closed. If they are still not closed, dismantle the temperature
