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make a hasty conclusion based on only one abnormal phenomenon .It is advisable to find
out two or more abnormal phenomenon ,or conduct troubleshooting comprehensively with
the aid of instruments or other ways ,because several kinds of troubles may share a
common abnormal phenomenon ,and two or more abnormal phenomena may occur
simultaneously due to a certain trouble .With this method ,you can reject some suspicious
troubles and finally make a correct judgment .
7 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 There are so 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 .
