13 The following details are known about a 250 hp, 230 V, 435 r/min de shunt motor: nominal full-load current: 862 A insulation class: H weight: 3400 kg external diameter of the frame: 915 mm length of frame: 1260 mm a. Calculate the total losses and efficienc at full-load. b. Calculate the approximate shunt field exciting current if the shunt field caus 20 percent of the total losses. c. Calculate the value of the armature resistance as well as the counter-emf, knowing that 50 percent of the total lo at full-load are due to armature resista d. If we wish to attain a speed of 1100 r/r

13 The following details are known about a 250 hp, 230 V, 435 r/min de shunt motor: nominal full-load current: 862 A insulation class: H weight: 3400 kg external diameter of the frame: 915 mm length of frame: 1260 mm a. Calculate the total losses and efficienc at full-load. b. Calculate the approximate shunt field exciting current if the shunt field caus 20 percent of the total losses. c. Calculate the value of the armature resistance as well as the counter-emf, knowing that 50 percent of the total lo at full-load are due to armature resista d. If we wish to attain a speed of 1100 r/r

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

P2:= A 4-pde,250V series motor has a wave Connectedl anmature with 1254 Gnductors. The Flux per pole is 22 m wb when the motar is taking 50A. Iren and fridion losses amount to Lkw. Amature resistanceis 0.202 and series field resistance is o.202 Calculate - (() the speed () the shaff torque the efficiengy (ii l
For a 18600W 2400rpm DC motor, the following values are given: Ra = 0.089 2 (value at room temperature (250C)), La = 0.00144 H, KT = 0.85 Nm / A and KV = 0.851 V / (rad / s)), (In calculations Use the hot resistance values at 1000C.) (Take the rated field winding losses as Wf= 210W.) If this DC machine is operating as a motor with rated flux at rated speed, calculate the rated torque (TR), rated current (IR), rated voltage (VR), efficiency (n) at the rated point, taking into account the winding losses. Find the speed (@NL) of this motor in no-load condition. TR Nm IR А VR V Eff = % ONL= rpm
12. The IR-compensation in frequency control of induction motors is used for: a) compensation of the voltage drop in the active resistance of the stator winding. b) compensation of the voltage drop in the inductive reactance of the stator winding. c) keeping the motor voltage constant. d) keeping the motor speed constant U₁ U₁ Us0 0 f. f₁
22. A) Why is the power factor of a lightly loaded 3-phase squirrel-cage induction motor very low? a) most of the power supplied to the motor at light loads is magnetization or inductive power b) most of the power supplied to the motor at light loads is resistive power c) most of the power supplied to the motor at light loads is capacitive power d) none of the above B) What happens to the power factor as load is increased on the motor? a) the power factor increases b) the power factor deceases c) remains the same
A 4 pole10V, DC shunt motor operates on a load current 10A, having wave connected armature with 200 conductors. The flux per Pole is 25 m Wb. Resistance of shunt field winding is 1 ohm and resistance of the armature is 0.15 ohm. a) what would be the back emf?
45) A 40hp, 440V, four pole dc motor has an armature wave-wound with 846 conductors and the commutator has 141 segments. The full load efficiency is 85% and the shunt current is 1.25A. If the brushes are shifted backward through segments from the geometric neutral axis, calculate (a) The demagnetizing ampere-turns per pole (b) The distorting ampere-turns per pole on full load.
Answer it right..
An armature controlled DC motor has the following parameters: Tf = 0.03 Nm KT = 0.15 Nm/A Imax = 2.4 A KĘ = 0.15 Vs/rad Wmax = 5000 rpm R = 0.8 Ohms 1. Determine the following: (i) The maximum output torque. (ii) The maximum power output. (iii) The maximum armature voltage. (iv) The no load motor speed when e = Emax 2. Plot the following relationships: (i) Torque versus current (ii) Induced voltage versus speed 3. If the above motor is operated at 3000 rpm with a load torque of 0.15 N.m, determine the armature voltage