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HVAC
28
d. REFRIGERATION CYCLE TROUBLESHOOTING
Sr.
No.
Problem
Possible Cause
Remedy
1
Insufficient re-
frigerant
Condition
Air conditioner does not cool effectively
Symptoms in refrigerant cycle
Pressure on both the high and low pres-
sure sides is low
Air around the air outlet is slightly cold
Cause
There is gas leakage in the refrigerating
cycle
Diagnosis
Insufficient refrigerant in the refrigerating
cycle
Refrigerant leakage
Countermeasures
Locate the leakage and
repair
Recharge refrigerant to
the specified amount
2
Excessive refrig-
erant or
insufficient con-
denser cooling
.
Condition
Air conditioner does not cool effectively
Symptoms in refrigerant cycle
Pressure on both the high and low pres-
sure sides is high.
Cause
Refrigerant is overcharge in the refrigerat-
ing cycle causing poor cooling
performance
Condenser cooling performance is poor.
Diagnosis
Excessive refrigerant in the refrigerating
cycle.
Overcharged refrigerant.
Poor condenser cooling performance.
Countermeasures
Clean the condenser.
Tighten the fan belt to
the correct tension.
Above are all normal
check the refrigerant.
3
Entry of moisture
in the refrigerant
cycle
Condition
Air conditioner alternately cools and
does not cool.
Symptoms in refrigerant cycle
During operation, the pressure on the low
pressure side alternates between vacuum
and normal.
Cause
The moisture mixed in the refrigerant in
the refrigerating cycle freezes in the ex-
pansion valve orifice, blocking the cycle.
After a time, the ice melts and normal
conditions return
Diagnosis
The drier is in an oversaturated condition.
The moisture in the refrigerating cycle
freezes the expansion valve orifice, im-
peding refrigerant circulation.
Countermeasures
Remove the moisture by
repeated evacuation.
Recharge new refriger-
ant to the specified
amount.