Evaluation of maximum rotor temperatures in TEFC inverter-fed motors

Based on the need to provide clearer application guidelines for motors supplied from adjustable-speed drives in Class I, Division 2 areas, the authors decided to conduct a test program to investigate the impact of adjustable-speed drives on totally-enclosed fan-cooled (TEFC) motor rotor temperatures. Hopefully, the results of these tests will foster industry discussion and increase collaboration among users and manufacturers.