Evaluation of maximum rotor temperatures in TEFC inverter-fed motors

Users must have data on maximum motor rotor surface temperatures under "normal operating conditions" to safely apply inverter-fed induction motors in hazardous Class I, Division 2 areas. Rotor surface temperature data is presented for a TEFC (totally enclosed fan cooled) chemical duty induction motor under various inverter setups and operating conditions. A proposed definition of "normal operating conditions" for inverter-fed induction motors is suggested for industry consideration.