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Remedy
Dismantle the system. Remove the dry filter and purge the tubing with nitrogen. Next,
install a new filter. Then evacuate it and fill with refrigerant.
4) Clogged filter
Analysis of Trouble
The complete clogging of the filter rarely occurs. Oftentimes, there is an accumulation of
paste-like matter formed from dust on the filter. Tapping the filter may remove part of the
paste-like matter. When the filter is clogged, it will be cooler than normal.
Remedy
The same as described for the capillary clogged with dirt.
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Troubles of Compressor
1) Broken gas suction and discharge valve blocks
Analysis of Trouble
The compressor works by opening and closing the gas suction valve and discharge valve
to suck and discharge the refrigerant. If the valve block is broken, the refrigerant cannot
be discharged. This prevents refrigeration.
Remedy
It is quite difficult to differentiate this trouble from others because they have similar
symptoms. When repairing, listen attentively for abnormal sounds coming from the
compressor. Oftentimes, broken pieces of valve block strike against the cylinder. Check
to see if the compressor casing is too hot. 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 will be very high. Whereas when the gas discharge valve block is broken, the
discharge pressure gauge pointer will swing drastically and the discharge pressure will be
very high. In both cases, stop the compressor at once. If possible, open the cylinder
cover, check the valve block, and repair it.
•
Compressor suddenly stops
Very often, when the compressor suddenly stops, the gas suction pressure and/or
discharge pressure have exceeded their respective prescribed ranges. When this
happens, the pressure-operated protective relay automatically shuts off the power to the
compressor. Below we discuss the reasons for high gas discharge pressure and low
suction pressure.
