3. A 4-pole wound- rotor induction motor has a Wye connected stator and a Delta connected rotor with the same number of conductors on each. The rotor resistance and reactance at stand still is are 0.18 and 0.75 ohm per phase respectively. If the voltage impressed on the stator is 110 V at 60 Hz , calculate the rotor current IR a. at starting b. when the speed is 1720 rpm

3. A 4-pole wound- rotor induction motor has a Wye connected stator and a Delta connected rotor with the same number of conductors on each. The rotor resistance and reactance at stand still is are 0.18 and 0.75 ohm per phase respectively. If the voltage impressed on the stator is 110 V at 60 Hz , calculate the rotor current IR a. at starting b. when the speed is 1720 rpm

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

6- Which of the following supply is given to the rotor winding of 3-Phase Induction Motor: a) DC Supply b) AC Supply c) No Supply d) Pulsating Supply 7- 3-Phase Induction Motor will have Starting Torque and Starting Current a) High, High b) Low, Low. c) High, Low d) Low, High 8- Which of the following method is used for controlling the speed of an induction motor: a) Changing number of stator poles b) Supply voltage control c) Frequency control d) All the options are correct 9- Which of the following method cannot be used for starting of 3-Phase Squirrel Induction Motor: a) Star-Delta Starting b) Line resistor startling c) transformer Starter d) Rotor Resistance Starting 10- The rotor of a stepper motor has no: a) windings b) commutator c) brushes d) all of the above
The rotor of a 3-phase, 60-Hz, 4-pole induction motor gets a total of 120kW through the air gap with a rotor frequency of 3Hz. a. What is the rotor speed (RPM)? b. What is the rotor copper loss (W)?
If a 4-pole induction motor has a synchro- nous speed of 1500 r.p.m., then, supply fre- quency is (1) 50 Hz 60 Hz (iii) (ii) 25 Hz (iv) none of the above
A 60-Hz induction motor runs at 860 r/min at full load. Determine a. the synchronous speed, b. the frequency of the rotor currents Note: Number of poles are 8.
3.An induction motor has a rotor resistance and reactance at standstill of 0.1 ohm and 3.5 ohm respectively. At standstill the voltage induced to the rotor is 60volts per phase. If the slip is 5%, determine the rotor current
A 3-phase induction motor is wound for 4 poles and is supplied from 50-Hz system. Calculate the synchronous speed the rotor speed, when slip is 4% and rotor frequency when rotor runs at 600 rpm.
In the case of an 8-pole induction motor, the supply frequency was 50-Hz andthe shaft speed was 735 rpm. What were the magnitudes of the following:a) synchronous speed and b) speed of slip.
2. What is the speed of an induction motor of six poles at 60 HZ, if the percent slip is 2.5 %?
A three-phase, 60 Hz induction motor operates at a slip of 2.5% and a speed of 1170 RPM. a. What is the synchronous speed of this motor? b. How many poles does this motor have?
13 A three-phase induction motor has a mechanical speed of 720 [rpm] and at full load has a slip of 5%. The number of poles and the frequency of this motor are: 4 poles 50 Hz. 6 poles 50 Hz. 8 poles 50 Hz. 6 poles 60 Hz.
An 8 pole, 50 Hz slip ring induction motor runs at a slip of 2.67% on full load. The rotor resistance per phase of the winding is 0.2 ohm. What external resistance per phase must be added in the rotor circuit so that the motor now runs ate a slip of 17.33% such that the torque remains same in both the cases. (Ans: 1.1 ohm)
0-4:-A three phase induction motor has 4-pole runs at 1440 rpm on 500 V, s0 Hz. The mechanical power developed by the rotor is 20.3 hp. The mechanical losses are 2.23 hp. Determine (a) the slip (b) the rotor copper losses, and (c) the efficiency.