Haier PBFS21EDAW, Service Manual

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1 . Analysis of Troubles and Troubleshooting
A. Poor Refrigerating Effect
The so-called “poor refrigerating effect “ refers to the fact that the refrigerator can operate and
refrigerator normally, but the temperature in the refrigerator cannot drop to the prescribed
value under the stipulated working conditions. In view of there are many causes for this
phenomenon, we are going to discuss and analyze it in the following 7 aspects:
1) Leakage of refrigerant
Analysis of Trouble
The leakage of refrigerant in the system will result in an insufficient refrigerating capacity, the
resulting phenomena are its lower gas suction pressure and exhaust pressure as well as
higher exhaust gas temperature. The exhaust tube feels rather hot, and a continuous gas
flowing sound louder than usual can be heard at the outlet of the capillary, and no frost or a
smaller quantity of loose frost appears on the evaporator. After shut down, the balance
pressure in the system is usually lower than the saturation pressure corresponding to the
same ambient temperature.
Remedy
In case there is leakage of refrigerant from the system, do not hurry to recharge it with
refrigerant, manage to find out leak points immediately, and make a note of from where it
leaks ---welding points and parts. After having them repaired, recharge refrigerant.
There are so many joints and sealed surfaces in a refrigerator, accordingly, quite a lot
potential leak points do exist in the system. In troubleshooting, pay attention to those parts
that are liable to leak, check main connection points for oil seepage and tubing for cracks. If
there is no severer leak point, charge the system with nitrogen and detect leak points with the
commonly adopted method, repair them, evacuate, charge the system with refrigerant, and
then turn on the refrigerator to make a test run.
2) Too much refrigerant charged into the system
Analysis of Trouble
a) In case the amount of refrigerant charged into the system exceeds its nominal capacity, the
superfluous refrigerant will of course take some space of the evaporator, thus reducing its
heat-dissipation area and hence the refrigerating efficiency of the system. The abnormal
phenomena caused by this reason are as follows: the gas suction and exhaust pressures are
generally higher than their respective normal values, the temperature of its condenser is
higher and the electric current of the compressor rises, loose frost forms on the evaporator,
the refrigerator temperature drops slowly, and frost appears on the gas return tube .
b) In case excessive refrigerant has been charged, the liquid refrigerant that can not
evaporates in the evaporator will return to the compressor, and thus a phenomenon of “liquid
striking” will occur. The liquid refrigerant evaporates and effervesces as soon as it flows into
the refrigerating oil at the bottom of compressor .If the condition is severe, foams will fill all
over inside the compressor housing and be sucked by the piston, causing damage to the
components of compressor.
TROUBLESHOOTING