Occasionally a technician may need to temporarily add oil to a semi-hermetic reciprocating compressor to maintain an adequate oil level, if the oil has been trapped out in the evaporator or suction line. This additional oil should not be left in the system.
The cause of the oil trapping should be identified and repaired in a timely fashion. If the additional oil returns to the compressor, it could cause damage as a result of oil slugging or excessive oil pumping.