Patent ID: 8079227

Claim:
A method of controlling the frequency of a compressor comprising: executing a capacity control program, the capacity control program establishing an operating frequency of a compressor; comparing the operating frequency to a nominal minimum frequency for the compressor, the nominal minimum frequency for the compressor being established by a manufacturer of the compressor; comparing the operating frequency to a predetermined minimum frequency for the compressor in response to the operating frequency being less than the nominal minimum frequency, the predetermined minimum frequency being less than the nominal minimum frequency; and overriding the capacity control program in response to the operating frequency being less than the nominal minimum frequency, overriding the capacity control program comprising: operating the compressor for a predetermined time period in response to the operating frequency remaining less than the nominal minimum frequency and the operating frequency remaining greater than or equal to the predetermined minimum frequency; and shutting down the compressor in response to an expiration of the predetermined time period.