A 20kW, 4-pole induction motor is designed to operate from a 440V, 50Hz, three-phase supply, and when operating at full power on this supply it runs at 1470rpm. The motor efficiency is 90% under both conditions. What supply frequency will be needed to make this motor run at 1270rpm while delivering a shaft power of 12.5kW?

A 20kW, 4-pole induction motor is designed to operate from a 440V, 50Hz, three-phase supply, and when operating at full power on this supply it runs at 1470rpm. The motor efficiency is 90% under both conditions. What supply frequency will be needed to make this motor run at 1270rpm while delivering a shaft power of 12.5kW?

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter32: Three-phase Motors

Section: Chapter Questions

Problem 6RQ: Name three factors that determine the torque produced by an induction motor.

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