Patent ID: 6874329

Claim:
A method for operating a vapor compression system having a compressor driven by a variable frequency drive, wherein said compressor feeds a refrigerant loop, wherein said refrigerant loop includes a cooling circuit for said variable frequency drive, and wherein a flow control member is positioned for controlling flow of refrigerant from said refrigerant loop to said cooling circuit, comprising the steps of: sensing an operating temperature of said variable frequency drive; and controlling said flow control member based upon said operating temperature, further comprising selecting a set point temperature for said variable frequency drive, and controlling said flow control member to increase refrigerant flow to said cooling circuit when said operating temperature exceeds said set point temperature, wherein said flow control member has a maximum setting corresponding to a maximum flow of refrigerant to said cooling circuit, and further comprising reducing a power rating of said variable frequency drive when said operating temperature exceeds said set point temperature and said flow control member is at said maximum setting.