A 209-V, three-phase, six-pole, Y-connected induction motor has the following parameters: R1 = 0.128 Ω, R’2 = 0.0935 Ω, Xeq =0.49Ω. The motor slip at full load is 2%. Assume that the motor load is a fan-type. If an external resistance equal to the rotor resistance is added to the rotor circuit, calculate the following: a. Motor speed, Starting torque, Starting current, and Motor efficiency (ignore rotational and core losses) b. Calculate the value of the resistance that should be added to the rotor circuit to reduce the speed at full load by 20%. Find the motor efficiency. c. If the voltage is reduced by 20%, calculate the Motor speed, Starting torque, Starting current, and Motor efficiency (ignore rotational and core losses) d. If the supply frequency is reduced by 20%, calculate the Motor speed, Starting torque, Starting current, and Motor efficiency (ignore rotational and core losses) ..

A 209-V, three-phase, six-pole, Y-connected induction motor has the following parameters: R1 = 0.128 Ω, R’2 = 0.0935 Ω, Xeq =0.49Ω. The motor slip at full load is 2%. Assume that the motor load is a fan-type. If an external resistance equal to the rotor resistance is added to the rotor circuit, calculate the following: a. Motor speed, Starting torque, Starting current, and Motor efficiency (ignore rotational and core losses) b. Calculate the value of the resistance that should be added to the rotor circuit to reduce the speed at full load by 20%. Find the motor efficiency. c. If the voltage is reduced by 20%, calculate the Motor speed, Starting torque, Starting current, and Motor efficiency (ignore rotational and core losses) d. If the supply frequency is reduced by 20%, calculate the Motor speed, Starting torque, Starting current, and Motor efficiency (ignore rotational and core losses) ..

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 13RQ: A squirrel-cage induction motor is operating at 1175 RPM and producing a torque of 22 Ib-ft. What is...

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A squirrel-cage induction motor is operating at 1175 RPM and producing a torque of 22 Ib-ft. What is the horsepower output of the motor?
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