A 3-phase, 440-V, delta-connected, 4-pole 50-Hz induction motor runs at a speed of 1447rpm when operating at its rated load. The equivalent circuit has the following per-phase:parametersr1=0.2 0,x1=x2'=2 0, r2'=0.4 N, rc=200 Q , xo = 40 0%3DUsing the approximate circuit, determine, for rated load, the values of line current and powerfactor, torque, output power and efficiency. The mechanical loss is 1000 watts.

for a delta connected induction motor V=440V, P=4 poles , f=50 Hz Nr=1447 rpm, X1=X2'=2Ω, r2'=0.4Ω,…

A 3-phase, 440-V, delta-connected, 4-pole 50-Hz induction motor runs at a speed of 1447 rpm when operating at its rated load. The equivalent circuit has the following per-phase :parameters r1=0.2 N, x1-x2-2 Ω, r2-0.4 Ω, rc=200 Ω, χφ 40 Ω Using the approximate circuit, determine, for rated load, the values of line current and power factor, torque, output power and efficiency. The mechanical loss is 1000 watts.

A 3-phase, 440-V, delta-connected, 4-pole 50-Hz induction motor runs at a speed of 1447 rpm when operating at its rated load. The equivalent circuit has the following per-phase :parameters r1=0.2 N, x1-x2-2 Ω, r2-0.4 Ω, rc=200 Ω, χφ 40 Ω Using the approximate circuit, determine, for rated load, the values of line current and power factor, torque, output power and efficiency. The mechanical loss is 1000 watts.

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.

See similar textbooks

Similar questions

Three-phase induction motor, 460 V 50 Hz, 4 poles, 50 hp with Delta, operating at 3.8% slip rated torque when receives Line Voltage 460 V, 50 Hz The parameters of the equivalent circuit per phase are as follows.R1 = 0.33, X1 = X2 = 0.42 and Xm = 30 Ohm / phase.Answer the following questions by neglecting the mechanical losses, Core losses and Stray load losses.A) Value of the rotor resistance R2 B) Maximum torque and rated speed C) line current and starting torque of motor
A three phase, 4 pole, 3300 V, 50 Hz, star connected Induction motor, has identical primary and referred secondary impedance of value 3+j9 Ohm per phase. Using the approximate circuit, calculate: A. The full load torque at rated slip of 5%. B. The maximum torque at normal voltage and frequency.
A 3-phase, 440-V, delta-connected, 4-pole 50-Hz induction motor runs at a speed of 1447 rpm when operating at its rated load. The equivalent circuit has the following per-phase :parametersr1=0.2 Ω, x1=x2'=2 Ω , r2'=0.4 Ω, rc=200 Ω , xɸ = 40 Ω Using the approximate circuit, determine, for rated load, the values of line current and power factor, torque, output power and efficiency. The mechanical loss is 1000 watts.
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 110-V, 50-Hz single phase induction motor (split -phase) has the following constants for the main and auxiliary windings: Main winding, Zm (1.2 +j 25) ohm and auxiliary winding, Z,= (12+j 5) ohm. Determine (i) total current and power factor currents at time of starting, and (ii) phase angle between the main winding current and starting winding current.
Three-phase 460-hp, 415 V, 4-pole, 50 Hz induction motor is operating at overvoltage of 480 V and reduced load of 80% of the rated value and draws a line current of 624.06A. The losses at these operating conditions are as follows: The stator conductor loss is 12.6kW, the rotor conductor loss is 10.4kW, the core loss is 11.00kW; and rotational losses is 4.129 kW. Sketch the power flow diagram, enter the known values, and determine (a) rotor speed (b) shaft output torque (c) developed mechanical torque in Nm. (d) input power to the stator; (f) the input power factor. Do only part (a), (b) & (c)
1.Show that if three phase currents, each of equal magnitude and differing in phase by 120degree, flow in a three phase winding that are 120 degree apart from each other then it willproduce a rotating magnetic field of a fixed magnitude. 2. A three phase, 5-hp, 60Hz, 115V, 4-pole induction motor is operating at rated voltage, rated frequency, and 125 percent rated load has an efficiency of 85.4 percent. The stator conductor loss, rotor copper loss and core loss are 223.2W, 153W, and 114.8W respectively.Sketch the power flow diagram, enter the given data, and determine i) shaft speed ii) shaft torque 3. Can single phase induction motor be self-started? Explain the operation of a split phase single phase induction motor?
The equivalent circuit parameters of a 230-V, 1-phase, 6-pole, 60-Hz induction motor are: R1 = R2’ =10 ohms, X1 = X2’ = 10 ohms, and Xm = 100 ohms. At a slip of 5%, calculate (a) motor speed, (b) input current, (c)power factor, (d) developed torque. (e) at 230V, while running on no-load, is 31.4 W at 1.2 A.What is the approximate efficiency of the motor at 5% slip?
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.
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.
The equivalent circuit parameters of a 230-V, 1-phase, 6-pole, 60-Hz induction motor are: R1 = R2’ =10ohm, X1 = X2’ = 10ohm, and Xm = 100ohm. At a slip of 5%, calculate the developed torque and The input power to the motor at 230V, while running on no-load, is 31.4 W at 1.2 A. What is the approximate efficiency of the motor at 5% slip?
A 25 HP, 6 pole, 50 Hz, 3-phase slip ring induction motor runs at 960revolutions per minute on full load with a rotor current per phase of 35 A.Allowing 250 W for the copper loss in the short-circuiting gear, and 1000Wfor mechanical losses, find the resistance per phase of the three-phaserotor winding.