Haier HRN-186 Service Manual page 16

filter ,recharge refrigerant after evacuating ,and then seal the harging 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 rominent 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 emperature in the segment from the compressor outlet to
the condenser inlet .Because here is air in the system ,both the gas exhaust pressure and temperature
will rise ,and oreover ,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
If a direct cooling refrigerator is to be used for a prolonged period of time ,be sure to 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 drop down to the prescribed
range .
REMEDY
turn the refrigerator off ,and make preparations for defrosting ,open the refrigerator door to let the air
come in ,or use a fan to speed up air flowing so as to shorten the time needed for defrosting .Never
strike the frost layer with any iron tools or wood stick in order to avoid damage to the evaporator
tubing .
6) Refrigerating oil left in evaporator tubing
analysis of Trouble
During the process of refrigerating cycles ,a little refrigerating oil may remain in the evaporator
tubing ,and after a longer time of operation ,if there is considerable refrigerating oil left in the
evaporator ,the heat conduction effect will be severely affected ,thus causing a poor refrigerating
effect .