Remedy
According to the operating procedures, it is mandatory to turn the machine off and
several minutes later, open the refrigerant charging tube and let the refrigerant flow from
out, replace the dry filter, refill the refrigerant after evacuating and seal the charging port.
3. Air left in the refrigerating system
Analysis
Residual air in the refrigerating system will reduce its refrigerating efficiency. Major
effects are increase in 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
After shut down for several minutes, open the tubing, evacuate it and recharge the system
with refrigerant.
4. Low efficiency of compressor
Analysis
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 difficult to
block the discharge port with your finger.
5. Refrigerating oil left in evaporator tubing
Analysis
During the refrigerating cycles, small amounts of refrigerating oil may remain in the
evaporator tubing after a long time of operation. The presence oil will affect heat
conduction and result in poor refrigerating effect.
Remedy
It is quiet difficult to analyze the presence of oil left in the evaporator tubing because
several other faults show similar symptoms. It can generally be accessed based on the
frost formed on the evaporator .If the frost does not cover the evaporator and loosely
formed, you can conclude that the deterioration of refrigerating effect is due to the
accumulation of refrigerating oil left in the evaporator tubing. To clear off refrigerating
oil left in the evaporator, dismantle the evaporator, clean and dry it .In case is difficult to
Summary of Contents for RF-8888-174
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