19
RAU-SVX01G-GB
Troubleshooting guide
Problems symptoms
Problem cause
Action recommended
G) Insu
ffi
cient cooling capacity
Thermostatic expansion valve ”whistles”.
Not enough refrigerant.
Check refrigerant circuit tightness and add
refrigerant.
Excess pressure drops through
fi
lter drier.
Drier
fi
lter clogged.
Replace.
Excessive superheat.
Superheat not properly adjusted.
Check adjustment of superheat and adjust
thermostatic expansion valve.
H) Discharge pressure too high
Condenser abnormally hot.
Presence of uncondensable liquids in system,
or excess refrigerant.
Purge uncondensable
fl
uids and drain o
ff
excess refrigerant.
Condenser air output too hot.
Reduced air
fl
ow. Air intake temperature
higher than speci
fi
ed for unit.
Clean battery.
Check operation of motor fans.
I) Suction pressure too high
Compressor operates continuously.
Excess cooling demand on evaporator.
Check system.
Suction duct abnormally cold.
a) Expansion valve too far open.
a) Check for superheat and check that
expansion valve bulb is secure.
b) Replace.
Refrigerant
fl
ows back to compressor.
b) Expansion valve locked in open position.
J) Suction pressure too low
Excessive pressure drop through
fi
lter
drier. Refrigerant does not
fl
ow through
thermostatic expansion valve
Drier
fi
lter clogged.
Expansion valve bulb has lost its refrigerant.
Replace the deshydrator.
Replace the bulb.
Loss of power.
Expansion valve obstructed.
Replace.
Superheat too low.
Excessive pressure drops through
evaporator.
Check adjustment of superheat and adjust
thermostatic expansion valve.
Note:
The above is not a comprehensive analysis of the Scroll compressor refrigeration system. The aim is to give
operators simple instructions on basic unit processes so that they have the technical knowledge to identify and bring
defective operations to the notice of qualifi ed technicians.
Summary of Contents for RAUL 190
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