3. A 315-V, two-pole, 60-Hz Y-connected wound-rotor induction motor is rated at 25 hp. Its equivalent circuit components are R1 = 0.5 N R2 = 0.37 Q X1 = 0.65 2 X2 = 0.65 Q XM = 19 2 Pv = 295 W Pmisc = 0 W Pf = 235 W For a slip of 0.09, determine a) Line current /, b)Stator copper losses c)Power delivered to the rotor d)Power converted from electrical to mechanical form e)Overall motor efficiency

3. A 315-V, two-pole, 60-Hz Y-connected wound-rotor induction motor is rated at 25 hp. Its equivalent circuit components are R1 = 0.5 N R2 = 0.37 Q X1 = 0.65 2 X2 = 0.65 Q XM = 19 2 Pv = 295 W Pmisc = 0 W Pf = 235 W For a slip of 0.09, determine a) Line current /, b)Stator copper losses c)Power delivered to the rotor d)Power converted from electrical to mechanical form e)Overall motor efficiency

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...

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A single-phase, 120 V, 60 Hz, four-pole, split-phase induction motor has the following equivalentcircuit parameters: R1m=1.5Ω, R1a=2.5Ω, R/2=1Ω, X1m=2.5Ω, X1a =2.5Ω, X/2=1.5Ω, Xmag =40Ωa) Determine the standstill impedances (Zm, Za) of the windings.b) Determine the starting torque and the starting current of the motor if it is started from rated voltagemains as a resistor split-phase motor.c) Determine the value of the capacitor to be connected in series with the auxiliary winding toproduce maximum starting torque per ampere of starting current. Determine the value of thestarting torque and starting current.d) Compare the starting torque per ampere of starting current for cases (b) and (c)
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16. A single-phase, 1/4 hp, 230 V, 60 Hz, four-pole, 1710 rpm induction motor has the following equivalent circuit parameters for the main winding: R1m=9.5Ω, R02=10.8Ω, X1m=X/2=12Ω, Xmag=260Ω At 230V and rated speed, the core loss is 30W, and the friction and windage loss is 15W. The motor is connected to an 1 φ, 230V, 60Hz supply and runs at the rated speed. Determine:a) The slip.b) The motor current.c) The input power factor.d) The input power.e) The developed torque.f) The output shaft power and shaft torque.g) The efficiency.h) The rotor circuit frequencies and the rotor cu-losses.i) The ratio of the forward flux to the backward flux.
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) ..
The no-load and locked-rotor test results of a three-phase 10 HP, 220 V, 60 Hz, 6 poles star connected induction motor are; The no-load test: VNL=220 V, PNL=340 W, INL=6.2 A The locked-rotor test: VSC=54 V, PSC =430 W, ISC =15.2 A The voltage across the stator windings is 2 V when nominal DC current flows through it. Coefficient for DC resistance is 1,25. a) Calculate the equivalent circuit parameters and draw the complete single-phase equivalent circuit of the induction motor. b) Calculate efficiency of the motor for s=0.06 by using the approximate equivalent circuit (RFe core resistance is not ignored). c) Shaft torque for s=0,06 d) Slip value at the maximum (breakdown) torque, e) Maximum (breakdown) torque of the induction motor. f) Speed of the motor at maximum torque point. g) Rotor frequency at maximum torque.
Q2 / A four pole, 400V, 50 Hz Y-connected induction motor has a full load slip of 4 percent. The rotor resistance and stand - still reactance per phase are 0.1 and 1 respectively the ratio of stator to rotor turns is 4. Calculate: (a) Full load torque and starting torque.(B) Maximum torque and the slip at which it occurs.(c) The resistance to be added to the rotor circuit obtain the starting torque equal to maximum torque
Draw the circle diagram for a 5.6 kW, 400-V, 3-φ, 4-pole, 50-Hz, slip-ring induction motor from the following data : No-load readings : 400 V, 6 A, cos φ0 = 0.087 : Short-circuit test : 100 V, 12 A, 720 W. The ratio of primary to secondary turns = 2.62, stator resistance per phase is 0.67 Ω and of the rotor is 0.185 Ω. Calculate (i) full-load current (ii) full-load slip (iii) full-load power factor (iv) maximum torque full - load torque (v) maximum power.
1. A 10-hp, 4-pole, 25-Hz, 3-Ф induction motor is taking 9,100 watts from the line. The core loss is 290 watts; stator copper loss is 568 watts; rotor copper loss is 445 watts, and the friction and windage loss is 121 watts. Determine the output torque in Newton-meter. 2. For a three-phase induction motor having rotor circuit resistance of 6 ohms, maximum torque occurs at a slip of 0.6. Find the value of standstill rotor circuit reactance. 3. A 4 - pole, 3 - phase, 60 Hz squirrel-cage motor draws 21 A and 7 kW while driving its normal load. Under these conditions, its slip is 2%. When running idle, this motor draws 6 A and 580 W at normal voltage. With its rotor blocked, this motor draws 15 A and 500 W with 50 V applied. What is the output torque of this motor when driving its normal load. 4. A 4-pole, 50 Hz, 3- phase induction motor develops a maximum torque of 110 N-m at 1360 rpm. The resistance of the star-connected rotor is 0.25 Ω /phase. Calicul the value of resistance that must…
Type your question here A 4-pole 400 V, 50 Hz wound-rotor induction motor has the following circuit model parameters: R1= 0.3 ohm R2' = 0.25 ohm, X1= X2' = 0.6 ohm , Xo = 35 ohm and rotational loss of 1500 W ( Ro is negligible). When the motor running at 1425 rpm, calculate a) the motor efficiency and, b) the maximum gross power when exciting circuit is omitted.
Q2. For a 10 kW, 380V, three-phase, four-pole, 1200 r/min, delta-connected induction motor. Adopt a specific magnetic loading of 0.4712 Wb/m2 and a specific electric loading of 23000 ampere-conductors per metre. The motor has a full-load efficiency of 85% and a full-load power factor of 0.8. A square pole design may be assumed and the stator leakage impedance voltage drop may be ignored. Assume also that the winding is full-pitched and uniformly wound. To calculate the following design parameters (a) The approximate outer diameter and length of the rotor core (b) the air gap length of the motor (c) the turns per phase (d) the number of conductors per slot, if 3 slots per pole per phase are chosen
A 484 V, 18862 hp, 60 Hz, four pole, Y-connected induction motor has the impedance parameters R1 = 0.673 Ω, R2 = 0.338 Ω,X1 =j1.106Ω,X2 =j0.464ΩandXM =j26.3Ω,perphase referred to the equivalent circuit in the following figure. For a rotor slip of 2.2 percent at rated voltage and rated frequency, determine total impedance, stator current, maximum torque, slip at maximum torque.
A 4-pole, 115 V, 60 Hz, 1710 rpm, capacitor-start single-phase induction motor has been designed to produce maximum starting torque per unit starting current. The motor has the following parameters: R1m=1.5ohms, X1m=2.6ohms, R1a=2.5 ohms, X1a=2.5 ohms, Xmag=40 ohms, R/2=1 ohms, X/2=1.6 ohmsNa/Nm =l, Capacitor in series with auxiliary winding = 375 μF.a) Draw the equivalent circuit for the motor under starting conditions. Determine the value of the starting torque.b) Draw the equivalent circuit for the motor when it runs at the rated (i.e., full load) speed. Determine the torque developed at this speed.c) Determine the ratio of the starting torque to the torque developed at the rated speed.