Haier HRN-186 Service Manual page 21

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
Three suspended spring inside the compressor case are out of balance ,and strike against the
case ,moreover ,the wear of compressor parts may cause noise sometimes .
3) Resonance of tubing and loosening of parts
Improper and compact laying of tubes or the loosening of parts may cause vibration and noise .
4) Inspection method
To find the sources of noise ,press the vibration spot with your hand while the refrigerator is in
operation and listen attentively whether the vibration becomes weaker or vanishes .If the refrigerator
has not been levelly placed ,put a level meter on its top table and adjust the leveling screws on its
legs .In case noise occurs from the
compressor ,strike different locations on the side surface of its case using a rubber hammer or hand
hammer with a wood block in-between so as to determine whether the suspended springs are out
of balance or being seized .
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, then check the