Important Notice To Compressor Application - Hanbell RC2-F Series Manual

8.3 Important notice to compressor application

Pump down
Do not pump down the compressor on the chiller as a routine operation except only for temporary maintenance or
a long term shut down. Because pump down will cause extremely high temperature in the compression chamber
and overheat of the motor as well due to less amount of refrigerant in the suction side. When doing the pump
down, be sure to take notice of the items listed below :
a. Hanbell recommends that whenever doing the pumping down of the compressor, the compressor is also
recommended to run at 100% capacity.
b. Pump down should be done once each time, as it may be dangerous to the compressor, compression chamber
for pumping down repeatedly.
c. The minimum suction pressure when doing the pump down should be over 0.5kg/cm2G
d. The allowable length of time for pumping down a compressor should not be over 15 seconds.
e. When doing the pump down of compressor, must take notice of the high discharge temperature should not
exceed 110℃.
f. Take notice of high/low pressure reading the oil level of the compressor and the noise of running as well. If there
is any abnormal value or situation, then emergently stop the pump down.
Long term partial load operation
If compressors have to run at partial load below 50% continuously, though maybe within operation limits under
such operation condition and with temperature of motor below trip setting for overheating, insufficient dissipation
of heat in motor will occur due to lower flow rate of suction gas at partial load. If compressors operate under high
temperature for a long time, insulation of motor will deteriorate gradually at risk of serious motor damage finally. In
such severe operation conditions, Hanbell strongly recommends installation of liquid injection system to cool
motor coil and use of PT100 or PT1000 sensor as described in chapter 7.2 , to effectively control temperature of
motor while running. It is suggested to switch on liquid injection when temperature of motor coil is higher than
80℃ and turn off liquid injection when it's lower than 65℃.
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