5.a) A 4 pole, 3 phase induction motor operates from a 50 Hz supply. Calculate (a) Speed at which the magnetic field of the stator is rotating (b) Speed of the rotor when the slip is 0.04 (c) Frequency of the rotor current when the slip is 0.03 (d) Frequency of the rotor current at standstill 5.b) The power input to a 500 V, 50 Hz, 6 pole, 3 phase induction motor running at 975 rpm is 40 KW. The stator losses are 1 KW and the friction and windage losses total 2 KW. Calculate: (i) Slip (ii) Rotor copper loss (iii) Shaft power and (iv) Efficiency

5.a) A 4 pole, 3 phase induction motor operates from a 50 Hz supply. Calculate (a) Speed at which the magnetic field of the stator is rotating (b) Speed of the rotor when the slip is 0.04 (c) Frequency of the rotor current when the slip is 0.03 (d) Frequency of the rotor current at standstill 5.b) The power input to a 500 V, 50 Hz, 6 pole, 3 phase induction motor running at 975 rpm is 40 KW. The stator losses are 1 KW and the friction and windage losses total 2 KW. Calculate: (i) Slip (ii) Rotor copper loss (iii) Shaft power and (iv) Efficiency

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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Similar questions

1. The operation of Commutator in DC Motor is * O a) to convert dc to ac O b) to convert ac to dc O c) to convert fixed dc to variable dc O reverse the current direction in the rotating windings each half turn
8. A 3-phase induction motor is running at 2% slip. If the input to rotor is 1000 W, then mechanical power developed by the motor is ............ (i) 20 W (iii) 500 W (ii) 980 W (iv) 200 W
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A) Although the magnetic field for each phase of a 3-phase induction motor is merely switching back and forth between north and south poles, the resultant magnetic influence from all phases sets up a rotating magnetic field to cut the rotor conductors. a) true b) false B) In a two-pole stator winding of a 3-phase motor, how many revolutions does the rotating tr) magnetic field make in one cycle of the electrical current? a) one b) 60 c) 3600 d) none of the above
3.8 An induction motor having 8 poles runs at 727.5 rpm. If the supply frequency is 50 Hz, the emf in the rotor will have a frequency of (a) 1.5 Hz (b) 48.5 Hz (c) 51.5 Hz (d) 75 Hz
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why the slip of induction motor is never zero.
The actual rotor resistance referred to the stator in an induction motor is? O a. r2 O b. r2/(1-s) O c. r2/s O d. r2*(1-s)/s
Why do we need to have brushes in a squirrel-cage rotor type induction motor? (short answer)
A four-pole induction motor drives a load at 2478 rpm. This is to be accomplished by using an electronic converter to convert a 400-V dc source into a set of three-phase ac voltages. Part A Find the frequency required for the ac voltages assuming that the slip is 4 percent. The load requires 2 hp. Express your answer to three significant figures and include the appropriate units. f= Submit Part B Value I = HA Request Answer Submit If the dc-to-ac converter has a power efficiency of 90 percent and the motor has a power efficiency of 80 percent, estimate the current taken from the dc source. Express your answer to three significant figures and include the appropriate units. HÅ Value Units Request Answer ? Units ?
Which of the following statements about three-phase induction motor is false (A) The speed of rotation of the magnetic field is called the synchronous speed. (B) A three-phase supply connected to the rator produces a rotation magnetic field. (C)The rotating magnetic field has a constant speed and constant magnitude. (D) It is essentially a constant speed type machine.
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