Anti-friction bearing temperature rise for NEMA frame motors

The authors identify the location for monitoring the bearing temperature rises for NEMA frame, chemical industry, severe duty squirrel-cage induction motors. They then investigate the relationship between bearing temperature rise and the stator winding temperature rise. An overview of the types of most commonly used antifriction bearings, criteria for selection of such bearings, and factors affecting bearing life are also presented. It is found that bearing operating temperature is an important parameter in motor specifications. For optimum motor design, the bearing temperature specified should be consistent with the motor RPM and the winding temperature rise