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CG-SVX039C-GB
Compressor Service Information
Mechanical Compressor Failure
Replace the failed compressor(s) and change the oil in
the remaining compressor(s) along with the refrigerant
system liquid line filter drier.
Electrical Compressor Failure
Replace the failed compressor and change the oil in
the other compressor(s). Also add a suction filter with
cleanup cores and change the liquid line filter drier.
Change filters and oil until the oil no longer test acidic.
See “Oil Testing.”
Compressor Motor Megging
Motor megging determines the electrical integrity of the
compressor motor winding insulation. Use a 500 volt
megger. A less than 1 meg-ohm reading is acceptable
and 1000 ohms per nameplate volts is required to safely
start the compressor.
Compressor Current Imbalance
Normal current imbalance could be 4 to 15 percent
with balanced voltage due to motor design. Each phase
should register 0.3 to 1.0 ohms and each phase should
be within 7 percent of the other two phases. Phase to
ground resistance must be infinity.
NOTICE: Maximum allowable voltage imbalance is
2 percent.
Compressor Electrical Terminal Box
Be sure to protect the terminal box when unbrazing or
brazing compressor refrigerant piping connections.
Compressor Crankcase Heaters
Compressor crankcase heaters must be energized at
least eight hours before starting the CGAF / CXAF chiller.
This is required to boil refrigerant out of the oil before
startup. Ambient temperature (except 20°C and above)
is not a factor and the crankcase heaters must always be
energized prior to startup.
Refrigerant Piping
The compressor suction and discharge connections
and piping are copper clad steel for easy brazing. In
most instances, piping may be reused. If piping is not
reusable, order the correct service parts. Cut all tubing
with a tubing cutter to prevent copper filings from
entering the system. Cut the tubing in a straight length
of pipe after the compressor connection has been
unsweated. The line can then be reinstalled using a slip
coupling and brazing.
Notice: The compressor suction line configuration
must not be changed in any way. Changing compressor
suction line configuration will compromise proper oil
return to the compressor(s).
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