Haier HRF-660S Service Manual page 29

SERVICE MANUAL
Model:HRF-660S
current of the compressor rises ,loose frost forms on the evaporator ,the refrigerator temperature
drops slowly ,and frost appears on the gas return tube .
b) In case excessive refrigerant has been charged, the liquid refrigerant that cannot evaporates in the
evaporator will return to the compressor, and thus a phenomenon of "liquid striking" will occur .The
liquid refrigerant evaporates and effervesces as soon as it flows into the refrigerating oil at the bottom
of compressor .If the condition is severe, foams will fill all over 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, and several minutes
later, open the refrigerant charging tube and let the refrigerant escape from it, replace the dry filter,
recharge 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 .The prominent
phenomena are the increase in its gas suction and exhaust pressures (however ,the gas exhaust
pressure will not exceed its rated value ),obvious increase in temperature in the segment from the
compressor outlet to the condenser inlet .Because there is air in the system ,both the gas exhaust
pressure and temperature will rise ,and moreover ,the gas flowing sound is intermittent and obviously
louder .
Remedy
After shut down for several minutes, open the tubing, evacuate it and then recharge 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 hence the corresponding reduction of refrigerating capacity ,under the condition that
the refrigerant in the system is unchanged .This phenomenon occurs mostly when the compressor
has been used for quite a long time, its moving parts have worn to a considerable degree ,fit
clearance between various parts have increased and sealing property of its gas valve has
deteriorated ,resulting in an decrease in its actual gas discharge capacity .
Methods of Judgment
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 ,feel it if there is pressure at the discharge port with
your finger (For a normal compressor ,its discharge port is difficult to be blocked with your finger if
you just apply a little effort).
5) Too thick frost layer formed on evaporator
Analysis of Trouble
Issue 201001
Rev.
Ref1001S008V0
29