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bottom of compressor. If the condition is severe, foams will cover the inside the compressor
housing and be sucked by the piston, causing damage to the components of compressor.
Remedy
According to the operating procedures, it is mandatory to turn the machine off. After several
minutes, open the refrigerant charging tube and let the refrigerant escape from it, replace the dry
filter, refill the refrigerant after evacuating, and then seal the charging port.
3) There is air left in the refrigerating system
Analysis of Trouble
Residual air in the refrigerating system will reduce its refrigerating efficiency. Major effects are
an increase in temperature of the segment from the compressor outlet to the condenser inlet and
an increase in gas suction and exhaust pressures. However, the gas exhaust pressure will not
exceed its rated value. Due to the air in the system, both the gas exhaust pressure and
temperature will rise. In addition, the sound of gas flowing will become intermittent and louder.
Remedy
Turn off the refrigerator, and wait for several minutes. Next, open and evacuate the tubing. Then
refill the system with refrigerant.
4) Low efficiency of compressor
Analysis of Trouble
Low efficiency of a refrigerating compressor refers to the actual reduction of gas discharge
capacity and the corresponding reduction of refrigerating capacity under the condition that the
refrigerant in the system is unchanged. This typically occurs when the compressor has been in
use for a long time.
Remedy
Measure the high and low pressures with pressure gauges to see whether they are normal. If an
abnormal sound comes from the compressor or the temperature of its causing is too high, cut the
discharge port open and operate the compressor. Inspect to see if there is pressure at the
discharge port with your finger. In a normal compressor, it is to difficult block the discharge port
with your finger.
5) Too thick frost layer formed on evaporator
Analysis of trouble
If a direct cooling refrigerator is to be used for a prolonged period, make sure that you defrost its
evaporator regularly. If you fail to do so, the frost layer on the evaporator tubing will become
thicker and thicker. Heat conduction will be severely affected when the whole tubing is wrapped
with a transparent ice layer, and finally the temperature in the refrigerator cannot fall to the
prescribed range.
