Trane TVR Pro CO Series Service Manual page 91

Step 8: Vacuum drying and refrigerant charging
 Once all the compressors and other components have been fully connected, vacuum dry the system and recharge
refrigerant. Refer to the V6 Engineering Data Book, Part 3.
Figure 6-2.10: Inspecting compressor oil
This oil is a little
This oil is black
yellow, but is clear
- it has been
and transparent and
carbonized
the condition is
acceptable
This oil is still
transparent but there
are impurities which
Cloudy or gray
may clog the filter
oil indicates
abnormal
system
This oil contains
operation
particles of copper
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