The plate values of a three-phase cage induction motor are: 15 kW 400 V Star Connected 50 Hz 30.6 A 1430 min-1 cos$=0.86 F class IP 55 S1 11a / lin = 5.8 Ma / Mn = 2.2 MK / Mn = 2.5 a) Calculate the rated efficiency with the effective, reactive and apparent powers of the motor in rated operation. b) Calculate the starting current, starting torque and overturning moment at full voltage. c) Calculate the roll slip and speed, and approximate the torque rotation speed characteristic of the motor. Give information about the rotor cage shape. d) Calculate the slip at rated speed and the rotor frequency at rated operation. e) Explain whether star-delta start can be given to this motor.

The plate values of a three-phase cage induction motor are: 15 kW 400 V Star Connected 50 Hz 30.6 A 1430 min-1 cos$=0.86 F class IP 55 S1 11a / lin = 5.8 Ma / Mn = 2.2 MK / Mn = 2.5 a) Calculate the rated efficiency with the effective, reactive and apparent powers of the motor in rated operation. b) Calculate the starting current, starting torque and overturning moment at full voltage. c) Calculate the roll slip and speed, and approximate the torque rotation speed characteristic of the motor. Give information about the rotor cage shape. d) Calculate the slip at rated speed and the rotor frequency at rated operation. e) Explain whether star-delta start can be given to this motor.

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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