A water pump employs 3 phase, 50 HP induction motor which is started using a star delta starter. It is fed from feeder mains with a 3 phase, 440 volts, 50 Hz supply. Because of the drops in the feeder it is found that the starting torque is same for both star and delta connections. Calculate the resistance of the feeder. From the short circuit test on the motor the following details are obtained: V = 200 volts, I = 125 Amps, and pf = 0.4. If an identical feeder is run in parallel with the first one find the % increase in starting torque obtained with each connection. (Ans: 1.6 2, 37%, 119%)

A water pump employs 3 phase, 50 HP induction motor which is started using a star delta starter. It is fed from feeder mains with a 3 phase, 440 volts, 50 Hz supply. Because of the drops in the feeder it is found that the starting torque is same for both star and delta connections. Calculate the resistance of the feeder. From the short circuit test on the motor the following details are obtained: V = 200 volts, I = 125 Amps, and pf = 0.4. If an identical feeder is run in parallel with the first one find the % increase in starting torque obtained with each connection. (Ans: 1.6 2, 37%, 119%)

Delmar's Standard Textbook Of Electricity

7th Edition

ISBN:9781337900348

Author:Stephen L. Herman

Publisher:Stephen L. Herman

Chapter33: Single-phase Motors

Section: Chapter Questions

Problem 32RQ

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