Advances in Motor Protection for Small Hermetic Refrigerant Compressors

For hermetic air conditioning compressors, the use of inline internal motor protection makes it possible to directly protect the motor in its true operating environment. For this reason the use of the internal line-break motor protector in single-phase air conditioning compressors is becoming popular. Ambient air temperatures, voltage variations, and the strong influence of the surrounding refrigerant combine to set the duty requirements of the protector. Important factors in selecting, locating, and testing these protection devices for proper operational and reliability standards are described.