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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 is 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
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.
Remedy
Turn the refrigerator off and prepare for defrosting. Open the refrigerator’s door to let air
inside or use a fan to speed up air moving into the refrigerator to quicken the defrosting
process. Never strike the frost layer with any iron tools or wooden stick in order not to
damage the evaporator tubing
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