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ANALYSIS OF SERVICE AND TROUBLE SHOOTING
Part 6 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 cannot 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 .
REMEDY
ccording to the operating procedures ,it is mandatory to turn the machine off ,and everal minutes
later ,open the refrigerant charging tube and let the refrigerant escape om it ,replace the dry
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