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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 judgment 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 swing drastically and the
discharge pressure is very high. In the both cases, stop the compressor at once, and if
technique is available, open the cylinder cover and check up the valve block, repair it, or
replace it with a new one,
C. Sudden stop of Compressor during Its Running
The cause of sudden stop of a compressor during its running is mostly that the gas suction
pressure and/or discharge pressure exceed their respective prescribed ranges, thus
making a pressure-operated protective relay shut off the power to the compressor and stop
it. In the following we discuss mainly the reasons for causing excessively high gas
discharge pressure and low suction pressure.
1) Stoppage due to excessively high gas discharge pressure
