Carrier Corporation

Cornelius Holmes

Vishnu Mohan Sishtla

Michael Alan Stark

Steven James Holden

Jarso Mulugeta

A compressor is powered by a motor which is, in turn, powered by a variable speed drive (VSD). The switching frequency and voltage/frequency relationship of the VSD may be adjusted dynamically to maximize efficiency.

VSD control

A method for operating a vapor compression system having a compressor driven by a variable frequency drive, wherein the compressor feeds a refrigerant loop, wherein the refrigerant loop includes a cooling circuit for the variable frequency drive, and wherein a flow control member is positioned for controlling flow of refrigerant from the refrigerant loop to the cooling circuit including the steps of: sensing an operating temperature of the variable frequency drive; and controlling the flow control member based upon the operating temperature.

Refrigerant cooled variable frequency drive and method for using same

A control system for a refrigerant cooled variable frequency drive (VFD) for a chiller includes a controller which controls an electronic expansion valve to attempt to maintain a heat sink for the variable frequency drive within its design operating range. When the controller is unable to maintain the heat sink within its design operating range, a load on the chiller is reduced, either by reducing the frequency of the variable frequency drive, or if the chiller includes a compressor with internal guide vanes, by partially closing the guide vanes. The power rating of the VFD can thus be optimized based on its heat generating components operating at a controlled condition, unlike an air-cooled device which is dependent on the ambient environment.

Electronic expansion valve control for a refrigerant cooled variable frequency drive (VFD)

An improved transmission vent system for centrifugal compressors comprises a motor compartment, a transmission chamber, an impeller for moving refrigerant in a downstream direction, a guide vane located upstream of the impeller, and a vent pipe connected between the transmission chamber and an area upstream of the impeller and downstream of the guide vane. Refrigerant can be vented from transmission chamber to the area upstream of the impeller and downstream of the guide vane in order to eliminate the pressure differential between the transmission chamber and the compressor suction area upstream of the impeller during start-up.

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North Syracuse, NY, United States of America

Cornelius Holmes