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Troubleshooting and Diagnostics
D. Too short running period of compressor
E. Compressor runs without stop
F. Motor winding of compressor is in open circuit.
G. Too high noise of compressor
Possible cause
Solution
Control circuit is intermittently connected.
Check the following items:
a. Poor contact of contactor
d. Loose wiring connection
Possible cause
Solution
Power of the water chiller is not enough to bear a load
(unloading water temperature cannot be provided).
Check causes that lead to excessive load.
Poor thermo probe or control line
Change the thermo probe.
Change or repair the control line.
Electromagnetic contactor of compressor goes wrong.
Repair or change the electromagnetic contactor.
Valve block of compressor leaks (low discharge pressure
or high suction pressure)
Change the compressor
Insufficient coolant (low capacity, too high superheat
degree, too low superheating degree, and low low-
pressure pressure)
Identify leak points of coolant, repair, and fill with coolant.
Possible cause
Solution
Too high evaporator load (high return water temperature)
Check the following items:
a. Excessive water flow
b. Tool high return water temperature
Inadequate motor cooling (too high superheat degree)
Check the following items:
a. Improper setting of expansion valve
b. Failure of expansion valve
c. Blocked liquid line
Improper compressor voltage
Check the following items:
a. Too low or unbalanced power voltage
b. Loose power wiring
c. Poor electromagnetic contactor of compressor
Internal parts of compressor are damaged.
Change the compressor
Possible cause
Solution
Internal parts of compressor are damaged or broken
(compressor sounds like striking).
Change the compressor
Liquid backflow (low pressure pipe is abnormally cold and
presents low superheat degree)
Check and regulate superheat degree
Liquid coolant is available in the compressor when the
compressor is started (compressor housing is abnormally
cold).
Check whether the coolant is excessive.
