2205B0JE-DA-J-N_2014.05.
6 Troubleshooting
Screw Compressor J-series
6-4
Trouble
Direct causes
Factors
Actions
05
Abnormally
high
pressure
(abnormal
discharge
pressure)
Excessive
refrigerant charge
In some cases,
without enough
investigation of
other causes for
insufficient cooling,
insufficient refrig-
erant amount was
considered to be
the cause, and
refrigerant was
charged repeatedly.
Adjust refrigerant to proper amount.
Insufficient capacity
of heat exchanger
If the trouble is caused by change in
operating conditions, re-examine
the conditions to improve.
If it is difficult to improve, add more
heat exchangers or increase their
sizes.
Defect in discharge
pressure detection
feature
Malfunction in
abnormal high
pressure protection
device, pressure
sensor, relays, etc.
Identify malfunctioning devices,
examine their causes, and take
measures.
Then, replace malfunctioning
devices.
Liquid stoppage,
etc., by clogging in
connecting pipes
Remove clogging. Check oil
contamination level and replace oil
as necessary.
Closed outlet stop
valve for oil
separator
Neglected to
restore after
closing.
Human error
Open valve or stop immediately.
Make sure to perform tagout during
valve operation.
Make sure to perform a valve check
before starting compressor.
06 Abnormally
high
discharge
temperature
Overheating during
operation
Insufficient refriger-
ant circulation
Refer to Factors of item 02.
Heat load on load
side is higher than
design value.
Inspect the situation on load side
(loading volume, opening and
closing of doors, etc.), and take
necessary measures.
Malfunction in low
pressure protection
device, pressure
sensor, relays, etc.
Identify malfunctioning devices,
examine their causes, and take
measures.
Then, replace malfunctioning
devices.
Non-condensable
gases in the system
Leak on low
pressure side
Inspect for leak, and take necessary
measures.
Then, air purge the heat exchanger.
