Haier BC-117A Series, Service Manual

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phenomenon and other several trouble are tends to be confused .Generally
speaking ,you can make a judgment based on the frost formed on the
evaporator .If the frost does not cover the evaporator , and moreover ,it is
loosely formed ,you can make a judgment that the deterioration of
refrigerating effect is due to the accumulation of refrigerating oil left in the
evaporator tubing in case no other troubles have been found . To clear off
refrigerating oil left in the evaporator ,dismantle the evaporator ,purge it
thoroughly and then dry it .In case it is difficult to dismantle it ,charge
refrigerant from the evaporator inlet to wash it several times ,then purge and
dry it with nitrogen .
7) Flowing obstructed in refrigerating system
Analysis of Trouble
Because
the refrigerating system was originally not purged
thoroughly ,some of the filter screen meshes have been clogged by dirt
accumulated in the filter after using it for a certain time of period ,thus
resulting in a decrease in flow rate ,and hence a poorer refrigerating effect .
The abnormal phenomena caused by this kind of slight clogging in the
system are as follows: the gas discharge pressure is lower ,the temperature
of discharged gas drops down ,the position clogged has a temperature lower
than that in normal conditions ,and for a severe clogging ,even dew
condensation as frosting may appear .
Remedy
Purge the tubing ,and after replacing the dry filter with a new one or
clearing it thoroughly ,recharge the system with refrigerant and seal the
charging port .
B. No Refrigerating
The phenomenon that the compressor runs normally ,but no frost (or only
a little frost ) appears on the evaporator ,and the refrigerator temperature
does not drop down is called
“
no refrigerating
”
. There are many causes for
this trouble and it is relatively complicated , too . In servicing ,special attention
to finding direct causes for this phenomenon .Three main potential causes for
this trouble are analyzed below :
1) All refrigerant in the system has leaked out
Analysis of Trouble
Leak points in the refrigerating system have not been found and repaired
timely ,thus resulting in the total escape of refrigerant .There are two kinds of
leakage :I)
slow leakage for instance ,when we want to use a refrigerator that
has been put out of quite a long time ,we find the leakage of refrigerant ,or in
the course of its operation ,we have found that the refrigerator is gradually
becoming not so cold and finally no refrigerating cab be achieved ; ii)
fast
leakage in that case ,all the refrigerant will escape swiftly due to abrupt
rupture of system tubing .
Symptoms of total leakage of refrigerant are mainly as follows : the
Maintenance Service and Trouble Shooting