Specifications

16
COMPRESSOR START-UP
1. After circuit breaker and control circuit switches are
placed in the ON position and the compressor starts,
listen for unusual sounds. If unusual sounds are heard,
shut down the compressor, investigate the cause, and
correct. Possible problems are:
• excessive vibration
• excessive oil
• liquid slugging
• low oil
2. After the compressor has run 10 to 15 minutes and no
liquid floodback is evident, completely open suction
service valve. The other compressors within the system
should be started in the same manner.
3. To ensure operating oil levels are within acceptable
limits, closely observe the oil level in the compressors
until the system has stabilized. During operation all
refrigeration systems will lose some compressor oil to the
system because:
• All systems have a film of oil on the inside surface
of the piping. At start-up, the lines are dry and the
oil which coats the lines comes from the compressor
crankcase.
• Oil also traps in the low refrigerant velocity area of
the system and must be made up by adding oil to the
system. On systems with hot gas defrost, inspect
the compressor for excessive oil after the defrost
cycle has been completed.
The oil lost to the system must be replaced, but take care
not to add too much. The 06E and 06CC (50 to 99 Cfm)
compressors have been successfully started in supermar-
ket refrigeration configurations by adding only 1 quart