Patent ID: 7342756

Claim:
A method for detecting compressor degradation in a multiple circuit compressor system comprising steps of providing a multiple circuit compressor system comprising at least a first circuit comprising a first compressor, a first condenser, a first expansion device and a first evaporator and a second circuit comprising a second compressor, a second condenser, a second expansion device and a second evaporator; comparing a first value corresponding to an operating parameter of said first circuit with a second value corresponding to an operating parameter of said second circuit, wherein the comparing step comprises measuring the first value while the first circuit is operating, measuring the second value while the second circuit is operating, and comparing the first value and the second value; and wherein the comparing step comprises sequentially measuring the first value while the first circuit is operating and the second circuit is not operating and measuring the second value while the second circuit is operating and the first circuit is not operating, and comparing the first value and the second value.