An induction motor of 30 HP, 220 V, 450% of the rated current with therated voltage and delivers during the starting period, with 130 % of the normal torque. The full load efficiency and full load power factor of the motor is 80 and 70 percent, respectively. If an autotransformer is used as a starting unit and the starting torque of the load is only 50 % of the rated torque of the motor, Determine the starting voltage and the starting current of the line.

An induction motor of 30 HP, 220 V, 450% of the rated current with therated voltage and delivers during the starting period, with 130 % of the normal torque. The full load efficiency and full load power factor of the motor is 80 and 70 percent, respectively. If an autotransformer is used as a starting unit and the starting torque of the load is only 50 % of the rated torque of the motor, Determine the starting voltage and the starting current of the line.

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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