MP54 and MP55 oil differential pressure controls are used as safety switches to protect refrigeration compressors against low lubricating oil pressure. If the oil pressure fails, the control will stop the compressor after a predetermined time period has elapsed. MP54 and 55 are used in refrigerating systems using CFC, HCFC, HFC. MP54 has a fixed differential pressure setting. It also incorporates a thermal time relay with a fixed release time setting. MP55 have adjustable differential pressure and are available with thermal time relay.