COMPRESSOR LUBRICATION

  An adequate supply of oil must be maintained in the crankcase at all times to insure continuous lubrication. The normal oil level should be maintained at slightly above the center of the sight glass while operating and possible damage to the compressor valves.

  Compressors leaving the Copeland factory are charged wit Suniso 3G, 150 viscosity refrigeration oil, and the use of any other oil must be specifically cleared with the Copeland Application Engineering Department. The naphthenic base oil has definite advantages over paraffinic base oils occurs at substantially higher temperatures with the same oil-refrigerant concentration When this separation or two phase condition exists the oil floats on top of the refrigerant and the oil pump inlet at the bottom of the sump is fed almost pure refrigerant at start up.The resulting improper lubrication can result in bearing failure. Because of the lower separating temperature of Suniso 3G oil, the possibility of two-phasing is greatly reduced.

  Copelametic compressors are shipped with a generous supply of oil the crankcase. However the system may require more or less oil depending. On field installed systems, after the system stabilizes at its normal operating conditions, it may be necessary to add or remove oil to maintain the desired level.

On compressors with step-up gearboxes, the main oil pump may be driven mechanically from the gearbox, and the auxiliary pump operates during the start-up and run-down phases of the compressor train. Relief valves protect both pumps from the effects of excessively high pressures. Check-valves prevent reverse flow of oil through the stationary pump.