NR-BN30PGW, NR-BN30PGB, NR-BN30PS1, NR-BN30QGW, NR-BN30QGB, NR-BN30QW1, NR-BN30QS1 - Panasonic Other Service Manuals Service Manual (repair manual). Page 16

 

 

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the evaporator tubing ,because this kind of 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 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 compressor can be 
started easily (if there is no damage to the compressor parts) and its operating current becomes low, 
its gas suction pressure is high and discharge pressure is lower, the gas discharge tube feels rather 
cold, no sound of gas eruption from the liquid in the evaporator can be

 

heard, and no will gush out of 

the process tube if you cut it open after shutdown. 
Remedy 
Check the whole machine, particularly those locations which are liable to leak .After leak points have 
been found, repair them or replace them with new parts according to specific circumstances, then