07: Discharge Temperature Is Abnormally High - mycom 4032**C Series Instruction Manual

06: Unusually high pressure (continued)
Direct cause
Discharge pressure
detection function is
defective.
Outlet shut-off valve of oil
separator is closed.

07: Discharge temperature is abnormally high.

Direct cause
Overheated during
operation
Non-condensable gases
mixed into the system
Oil supply temperature is
high.
Defective discharge
temperature
detection/protection
feature.
Insufficient oil supply
Compound 2-stage Screw Compressor 4032**C
Root cause
Failure of high pressure
protection device, pressure
sensor, relay, etc.
clogging of pressure pipe
Operator forgot to restore after
shut down operation.
Human error
Root cause
Insufficient refrigerant flow
Heat load on load side is
higher than design value.
Failure of low pressure
protection device, pressure
sensor, relay, etc.
Leak on low pressure side
Heat exchange failure in oil
cooler
Oil temperature rise protection
feature does not function.
Failure of temperature
protection device, temperature
sensor, relay, etc.
See "Low oil pressure" in Item
04 above.
6-5
2201Q4JE-MY-C9-N_2018.01.
Chapter 6 Troubleshooting
Action
Identify defective devices, investigate
causes of failure and take necessary
actions.
Then, replace failed device(s).
Remove clogging, and check oil for
contamination/replace oil.
Open the valve or perform emergent
stop.
Be sure to conduct tagout while
handling valves.
Be sure to check valves before
starting the compressor.
Action
See the causes listed in item 02
above.
Inspect the conditions on load side
(warehousing volume,
opening/closing of doors, etc.), and
take necessary measures.
Identify defective devices, investigate
causes of failure and take necessary
actions.
Then, replace failed device(s).
Perform a leak check, and take
necessary measures.
Air-purge the heat exchanger.
For water-cooling system, see "Heat
exchange failure in heat exchanger" in
06 above.
For liquid cooling system, check liquid
supply expansion valve, temperature
sensor and related
relays/wiring/terminals, and take
necessary actions.
Check temperature protection device,
temperature sensor and related
relays/wiring/terminals, and take
necessary actions.
Identify defective devices, investigate
causes of failure and take necessary
actions.
Then, replace failed device(s).
Same as left