Large Wound-Rotor Motor with Liquid Rheostat for Refinery Compressor Drive

This paper includes practical application data and describes the important features involved in the use of wound-rotor induction motors with liquid rheostats for variable-speed compressor drives in semihazardous refinery areas. Specfically, it describes the actual installation of a 4000-hp motor driving a high-speed rotary compressor through gears, where a speed control of approximately 20 per cent is desired. Photographs of the installation are included, as well as summary of the first year of actual operation, the difficulties experienced, and remedial measures taken.