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accumulates there, the whole filter screen may be blocked totally, making the
refrigerant unable to go through. Clogging with dirt exhibits the same
symptoms as that with ice, namely, higher gas suction pressure, lower
temperature of discharged gas, and no gas flowing sound from the evaporator.
The difference between the both is as follows: if the clogging is caused by
dirt , tapping the suspicious clogged point (generally in the capillary or the
connection joint of the filter) may cause the refrigerant to flow through partially,
resulting in some corresponding change, whereas in that case if you heat it
with a hot towel, no reaction will happen, no flowing sound can be heard,
moreover, there is no periodic change. After rejecting the possibility of ice
clogging, it can be generally considered as the clogging due to dirt .
Remedy
Dismantle the system, remove the dry filter from it, purge the tubing with
nitrogen, install a new filter, then evacuate it and finally charge it with
refrigerant.
C) Clogging in filter
Analysis of Trouble
Total clogging of a filter is rarely to occur. This trouble is mostly caused by
the paste-like matter formed from the substances filled into the system or
other dust after the refrigerator has been used for a longer time, or by the dirt
accumulated gradually inside the filter. Sometimes, tapping the filter nay
cause a passage for flowing, Touching it with your hand, you will feel that it is
cooler compared with its temperature in the normal state.
Remedy
The same as described in the capillary clogging with dirt.
3) Troubles of Compressor
a) Breakage of gas suction and discharge valve blocks
Analysis of Trouble
The compressor works by means of the opening and closing of gas
suction valve and discharge valve to suck and discharge the refrigerant. If the
valve block is broken, the refrigerant can not be discharged, and hence no
refrigerating can be achieved.
Method for making judgement
It is quite difficult to differentiate this trouble from others because they
often have similar symptoms. In repairing, firstly, hear attentively if there is
some abnormal sound coming from the compressor (sometimes , the broken
pieces of valve block may strike against the cylinder), and feel the
compressor casing with your hand to ascertain whether it is too hot, this is
also helpful to the troubleshooting; secondly, measure the pressures at the
high and low pressure ports of the compressor with pressure gauges, if the
gas suction valve block is broken, the suction pressure gauge pointer will
swing violently and the suction pressure is very high, whereas when the gas
discharge valve block is broken , the discharge pressure gauge pointer will
Maintenance Service and Trouble Shooting
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