2201Q4JE-MY-C9-N_2018.01.
Chapter 6 Troubleshooting
Compound 2-stage Screw Compressor 4032**C
6-4
06: Unusually high pressure (abnormal discharge pressure)
Direct cause
Root cause
Action
Heat exchange failure in
condenser (heat
exchanger)
Heat transmission tubes and/or
fins are contaminated or
blocked.
Clean and wash.
Depending on the contamination
level, use chemical cleaning.
Water loss of water pump or
Failure in fan motor, thermo
switch, water spraying pipes,
cooling water pumps, etc.
Identify defective devices, investigate
causes of failure and take necessary
actions.
Then, replace failed device(s).
Faulty adjustment of cooling
water/brine flow
In case of manually adjusted valve,
readjust the valve.
When an automatic control valve
(including wax valve) is used,
investigate the cause and take
necessary actions.
Other causes of insufficient
flow of cooling water, etc.
Inspect filters installed on the
circulation route for clogging and
contamination, and take necessary
actions.
Inspect for leaks in circulation routes,
and take necessary actions.
Inspect water supply routes and/or
mechanisms, and take necessary
actions.
If frozen, take measures such as
improvement of heat insulation or
increase of temperature.
Deficiency in heat exchanger
performance
If the symptom is caused by change in
operating conditions, re-examine the
conditions for improvement.
If the symptom is caused by change in
installation environment, improve the
environment if possible.
In either case, if improvement
measure is difficult to be made, add
more heat exchangers or increase
their sizes.
Non-condensable gases
mixed into the system
Leak on low pressure side
* There are also cases where
the symptom was caused by
corrosion in suction
temperature gauge protection
tube
Perform a leak check, and take
necessary measures.
Air-purge the heat exchanger.
Refrigerant is excessive.
In some cases, insufficient
cooling is judged as caused by
insufficient refrigerant and, as
a result, refrigerant is charged
repeatedly.
Properly adjust the amount of the
refrigerant
Capacity of heat changer is
insufficient.
If the symptom is caused by change in
operating conditions, re-examine the
conditions for improvement.
If improvement is difficult, add heat
exchangers or increase their sizes.
