A10 Kw, 400 V, 3- Phase induction motor has full load efficiency of 0.87 and power factor 0.85. At standstill at rated voltage the motor draws 5 times full load current and develops a starting torque of 1.5 times full load torque. An autotransformer is installed to reduce the starting current to give full load torque at the time of starting. Calculate the full load current.

A10 Kw, 400 V, 3- Phase induction motor has full load efficiency of 0.87 and power factor 0.85. At standstill at rated voltage the motor draws 5 times full load current and develops a starting torque of 1.5 times full load torque. An autotransformer is installed to reduce the starting current to give full load torque at the time of starting. Calculate the full load current.

Introductory Circuit Analysis (13th Edition)

13th Edition

ISBN:9780133923605

Author:Robert L. Boylestad

Publisher:Robert L. Boylestad

Chapter1: Introduction

Section: Chapter Questions

Problem 1P: Visit your local library (at school or home) and describe the extent to which it provides literature...

See similar textbooks

Similar questions

Question A 3-phase, 415 V, 4-pole, 50 Hz induction motor draws 5 times the rated current at rated voltage at starting. It is required to bring down the starting current from the supply to 2 times of the rated current using a 3-phase autotransformer. If the magnetizing impedance of the induction motor and no-load current of the autotransformer is neglected, then the transformation ratio of the autotransformer is given by
A 2 hp 50 Hz 3-phase 220 V delta wired induction motor has a full-load rated speed of 1400 rpm. a) How many poles does the motor have? b) Calculate its rated output torque. c) What is the slip at full load? d) If the current is 6.37 A with a power factor of 0.79 at full load, what is the efficiency of the motor? e) Calculate the torque and approximate speed at ½ load. f) If a variable frequency drive were used to control the speed of this motor, what is the approximate maximum speed for the load from e)? What frequency would the drive be set to? Please answer all subpart either dislike is ready please all subpart in short please
When the speed of the dc motor is varied by changing the armature resistance, is to be held constant. O field flux O applied voltage O load current O armature current The starting torque of a three phase slip ring induction motor is to a three phase squirrel cage induction motor. when compared O very low O low same O high
A four-pole, three-phase induction motor drives a turbine load. At a certain operatingpoint the machine has 4 percent slip and 87 percent efficiency. The motor drives aturbine with torque–speed characteristic given by TL = 20 + 0.006ω2,where TL is theload torque at the shaft. Determine:(1) the torque at the motor-turbine shaft.(2) the total power delivered to the turbine.(3) the total power consumed by the motor.
A 30 kW, 460 V, 1180 rpm, 3 -phase, 60 Hz, Y-connected induction motor has a full-load efficiency of 93.6% and a power factor of 0.83 lagging. The resistance of the stator winding per phase is 0.14 N/phase. Determine: (a) The full-load active power drawn by the motor (b) The full-load line current (c) The full-load rotor winding losses (d) The rotational losses
1. The rotor resistance and reactance per phase of a three-phase wound rotor induction motor are 0.035 and 0.15 ohm respectively. If an additional resistance is added, the starting torque is one half of maximum torque and the full load torque is three-fourth of the maximum. Determine the following: a. Full load speed b. speed at maximum torque c. value of additional resistance per required to achieve these conditions.
7-5. A 50-kW, 440-V, 50-Hz, six-pole induction motor has a slip of 6 percent when op- erating at full-load conditions. At full-load conditions, the friction and windage losses are 300 W, and the core losses are 600 W. Find the following values for full- load conditions: (a) The shaft speed n. (b) The output power in watts (c) The load torque Tloud in newton-meters (d) The induced torque Tiad in newton-meters (e) The rotor frequency in hertz
An 8-pole, 50 Hz, 3-phase induction motor has a full-load slip 2.5% and maximum torque of twice the full-load torque. At what value of slip does the maximum torque occur? Ans[0.093]
2.b) Explain the speed control of the induction motor with the PWM method. please write it with computer
A 240 V, 60 Hz, Delta connected, 870 r.p.m., Eight poles, Three-Phase Induction Motor has the following per phase parameters: R1 = 0.07, R2 = 0.05, X1 = X2 = 0.2, Xm = 6.5, Draw the approximate equivalent circuit and determine the following: I. Starting Torque Maximum Torque II. I. Rated Torque IV. Stator Current V. Power Factor VI. Input Power VII. Rotor Current VIII. Magnetizing Current IX. Stator copper loss Х. Rotor copper loss
An 8-pole, 50 Hz induction motor has a full-load slip of 3% and a maximum torque of twice the full-load torque. At what value of slip does the maximum torque occur?