4. Troubleshooting
Analysis and countermeasure of abnormalities
SMGB0097 rev.0 - 07/2015
124
Phenomenon
Cause
Check Item
Action · Countermeasure
The
machine is
working, but
the cooling
effect is
poor
Load bigger than cooling capacity.
Calculate heat load.
Set the machine to a larger
capacity
Suction
pressure is
too low.
(Low
pressure
interruption
control
activated)
Gas leakage or insufficient
amount of refrigerant
Check super heat
Charge correct refrigerant volume
after checking gas leakage
Clogging of expansion valve
Check for clogging
Remove clogging
Malfunction of the expansion
valve
Check operation of expansion
valve
Replace expansion valve
Clogging of suction pipes
Check whether there is temp
difference in the pipes
Remove clogging
Malfunction of check valve
There is temperature difference
at the check valve
Replace check valve
Insufficient volume of water
Check cold water inlet/outlet
temperature difference
Increase volume of water
Pump inverse rotation
Check rotational direction
Fix to correct direction
Formation of lime deposit
inside heat exchanger
Check for dirt at the heat
exchanger
Clean heat exchanger
Discharge
pressure
too high
(High
pressure
switch
activation)
Refrigerant overcharge
Check cycle temperature
Charge correct volume
Mixture of non-condensable
gas in refrigerant cycle
Stop the chiller unit and check
the relation between water
temperature and pressure
Recharge refrigerant after vacuum
pumping
Clogging of pipes at discharge
side
Check for clogging
Remove clogging.
Clogging of expansion valve
Check for clogging
Malfunction of expansion
valve
Check operation of expansion
valve
Replace expansion valve
Malfunction of check valve
Check temperature difference
before and after check valve
Replace check valve
Faulty compressor
Check pressure, cycle
temperature and current
Compressor replacement
The
machine is
working, but
it produces
abnormal
noises
Sounds
come from
the com
-
pressor
Incorrect installation or
loosening of various
tightening bolts
Inspection of loosening of each
tightening bolt
Tighten bolts even more
Liquid compression
Check temperature and pressure
of suction gas
Secure super heat
Oil hammer
Check temperature and amount of
oil in suction gas
Check or replace compressor
Oil heater is not being
supplied power during stop
Check the power supply to the oil
heater
Replace oil heater
Exhaustion and damage
inside the compressor
Abnormal noises produced inside
the compressor
Compressor replacement
Howling from the electrical contactor
Check for rough contact
Replace contact
Vibration of cabinet
Check for loosening of screws
Retighten screws