Patent ID: 8390221

Claim:
A system for protecting a three-phase electric motor of a compressor, the motor receiving first, second, and third phases from a three-phase power supply, the system comprising: a single-phase line break protector that disconnects the motor from the first phase in response to a temperature being greater than a predetermined temperature threshold; a first current sensor that measures a current through the single-phase line break protector; and a control module that (i) determines a current value based on the measured current, and (ii) disconnects the motor from the second and third phases in response to the current value being less than or equal to a predetermined threshold, wherein the control module disconnects the motor from the first, second, and third phases when the current value is less than or equal to the predetermined threshold, and wherein the current value includes one of a peak of the measured current during a predetermined period and a root mean squared (RMS) of the measured current during the predetermined period.