Patent ID: 8459053

Claim:
A system comprising: a compressor connected to an evaporator; a suction temperature sensor that outputs a suction temperature signal corresponding to a temperature of refrigerant entering said compressor; an inverter drive connected to said compressor that receives electric power and modulates a speed of said compressor by modulating a frequency of said electric power; a heat sink temperature sensor that outputs a heat sink temperature signal corresponding to a temperature of a heat sink associated with said inverter; a control module connected to said inverter drive that receives said suction temperature signal, that monitors compressor power data and compressor speed data from said inverter drive, that calculates a saturated evaporator temperature of a refrigeration system associated with said compressor and said evaporator based on said suction temperature signal, said heat sink temperature signal, said compressor power data, and said compressor speed data; and that generates at least one of a control signal and a notification signal based on said calculated saturated evaporator temperature.