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. The paste-like matter formed from the substances
filled into the system mostly causes this trouble 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 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. Sudde n stop of Compresso r 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 hi gh gas discharge pressure
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Summary of Contents for HB21FNN
Page 23: ...CIRCUIT DIAGRAM 1 Brief principle diagram 23 ...
Page 24: ...2 Connect diagram 24 CIRCUIT DIAGRAM ...
Page 40: ......
