A single-phase, 120 V, 60 Hz, four-pole, split-phase induction motor has the following standstill impedances: Main winding: Zm =5+j6.25 Auxiliary winding: Za =8+j6 a) Determine the value of capacitance to be added in series with the auxiliary winding to obtain maximum starting torque. b) Compare the starting torques and starting current with and without the added capacitance in the auxiliary winding circuit when operated from a 120V, 60Hz supply

A single-phase, 120 V, 60 Hz, four-pole, split-phase induction motor has the following standstill impedances: Main winding: Zm =5+j6.25 Auxiliary winding: Za =8+j6 a) Determine the value of capacitance to be added in series with the auxiliary winding to obtain maximum starting torque. b) Compare the starting torques and starting current with and without the added capacitance in the auxiliary winding circuit when operated from a 120V, 60Hz supply

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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18. A single-phase, 120 V, 60 Hz, four-pole, split-phase induction motor has the following standstill impedances:Main winding: Zm =5+j6.25Auxiliary winding: Za =8+j6a) Determine the value of capacitance to be added in series with the auxiliary winding to obtain maximum starting torque.b) Compare the starting torques and starting current with and without the added capacitance in the auxiliary winding circuit when operated from a 120V, 60Hz supply.
A four-pole, single-phase, 120 V, 60 Hz induction motor gave the following standstill impedances when tested at rated frequency:Main winding : Zm =1.5+j4 ohmsAuxiliary winding : Za =3+j6 ohmsa) Determine the value of external resistance to be inserted in series with the auxiliary winding to obtain maximum starting torque as a resistor split-phase motor.b) Determine the value of the capacitor to be inserted in series with the auxiliary winding to obtain maximum starting torque as a capacitor-start motor.c) Determine the value of the capacitor to be inserted in series with the auxiliary winding to obtain maximum starting torque per ampere of the starting current as a capacitor-start motor.d) Compare the starting torques and starting currents in parts (a), (b), and (c) expressed as per unit of the starting torque without any external element in the auxiliary circuit, when operated at 120V, 60Hz.
Design and develop equivalent circuit model of a single phase Induction motor with th consideration of core losses present with the parameter consideration of stator resistance R1 and reactance X1 and two rotor parameters which includes r2,x2 and magnetising reactance xm. (Illustration is required) Draw by hand please
a. A three-phase, 220-V, 60-Hz induction motor runsat 1,140 r/min. Determine the number of poles (forminimum slip), the slip, and the frequency of therotor currents.b. To reduce the starting current, a three-phasesquirrel cage induction motor is started byreducing the line voltage to Vs/2. By what factorare the starting torque and the starting currentreduced?
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A three-phase induction motor, operating at rated voltage and frequency, has a startingtorque of 1.35 times and a maximum torque of 2.2 times, both with respect to its rated-loadtorque. Ignoring the effects of the stator resistance and rotational losses and assumingconstant rotor resistance, determine the slip at the maximum torque;
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A 480 V, 2-poles, 60 Hz, Y-connected induction motor has an inductive reactance of 4ohm and the resistance of R, = 0.2ohm and R', 0.3ohm. The motor is driving a constant-torque load of 150 Nm at a speed of 3500 rpm. Assume that this torque includes the rotational components. Calculate the motor speed and starting current if the frequency is decreased to 50 Hz.
base on below mentioned Comparison of the performance indexes discuss and advice best induction motor.