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4- Troubleshooting
Gauge pressure
indication
Cause
Confirmation method
Action to take
Both discharge and
suction pressures are
high
Excess of refrigerant
Connect gauge
manifold to cycle
Recover refrigerant,
then refill with the
right amount of
refrigerant
Condenser cooling
malfunction
Condenser becomes
muddy and fins are
clogged and collapsed.
Defect of cooling fan
rotation.
Malfunction of fan
motor for condenser.
Clean up, hand repair
of fin and replacement
Misaligned Expansion
valve or thermal
sensing tube of the
Expansion valve is not
fit on regularly.
(Excess opening of
Expansion valve)
Defective refrigerant
flow control, the
thermal sensing tube
is not closely in contact
with the evaporator
pipe
Adjustment or
replacement
Air mixed in
refrigeration cycle
Just after compressor
stops, discharge
pressure will come
down immediately to
0.29 - 0.39 MPaG (3 - 4
kgf/cm²)
Evacuate air from cycle,
the charge with the
adequate amount of
refrigerant
Discharge pressure
is high and suction
pressure is low
Refrigerant cycle is
clogged between
compressor and
condenser
Appreciable
temperature difference
at the clogged location
Clean up inside the
cycle or replace the
part
Discharge pressure
is low and suction
pressure is high
Defect of the
compressor valve or
gasket
Discharge and suction
pressures balance
immediately after the
compressor stops.
(Defective compression
of compressor)
Replace the compressor
