3. A universal series motor has a resistance of 30 Q and inductance of 0.5 H. When connected to a 258 Vdc supply and loaded to take 0.8 A, it runs at 2000 rpm. Estimate the following parameter when connected to a 264 -V, 50-Hz ac supply and loaded to take 2.0 A(max value). (a) speed (b) power factor (c) torque

3. A universal series motor has a resistance of 30 Q and inductance of 0.5 H. When connected to a 258 Vdc supply and loaded to take 0.8 A, it runs at 2000 rpm. Estimate the following parameter when connected to a 264 -V, 50-Hz ac supply and loaded to take 2.0 A(max value). (a) speed (b) power factor (c) torque

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 13RQ: A squirrel-cage induction motor is operating at 1175 RPM and producing a torque of 22 Ib-ft. What is...

See similar textbooks

Similar questions

A 10 HP, 6-pole, induction motor has its maximum power factor of 0.82, that occur at full load. Estimate the maximum power factor if (i) there is a reduction in the air gap of 25%. (ii) the motor is rewound for 4 poles with the original airgap. Neglect the reluctance of the iron path.
A six pole three-phase 440-volts 50Hz, induction motor develops an 8-Hp at 955 rpm, the power factor being 0.85.Stator losses amounts to 400-watts and the frictional losses to 5-Hp. Calculate the (a) efficiency (b) the line current.
4 DECIMAL PLACES : 2. A 230-V, 50-Hz, 6-pole, single-phase induction motor has the following constants.r1 = 0.12 Ω, r2 = 0.14 Ω, x1 = x2 = 0.25 Ω, xm = 15 Ω.If the core loss is 250 W and the friction and windage losses are 500 W, determine the (a)efficiency and (b) torque at s = 0.05.
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.
What is the solution to this questionQ) A 250V, DC series motor has total resistance of 0.8 Ω. Its full loadcurrent and speed are 10 A and 1500 r.p.m respectively. If the torque isreduced to 50% .Determine the current and speed. Assume straight linemagnetization characteristics
A 440V, 50 Hz, 6 pole, Y-connected induction motor is rated at 75 kW. The equivalent circuit parameters are R1 Ω =0.082 Ω R2 = 0.070 Ω XM = 7.2 Ω X1 Ω =0.19 Ω X2 = 0.180 Ω In this problem, you are to calculate the pull-out torque. The slip is 0.04. a) Rth and Vth? b) Slip at pullout torque Smax? c) The pullout torque Tmax?
Design a DC motor circuit to drive A fan-type load with a torque equation equal to: TL=1.34×10−7ω2TL=1.34×10−7ω2 N.m The fan speed range is from 500 to 1200 rpm. To achieve the required operation, the armature voltage of the motor is adjusted by a single-phase, full-wave, ac/dc converter. The input voltage and frequency to the converter are 480 V (rms) and 50 Hz. choose the motor type, show the motor rating, αα range, Supply voltage, and frequency, and any required other information Modify the design to automatically adjust the voltage drive the load within the specified speed range. show the control variable, controller type, connection, and controller weights. design the single-phase, full-wave, ac/ dc converter. show design specifications, the reason for DC motor selection. correct manual circuit, and correct automatic closed-loop control circuit
Design a DC motor circuit to drive A fan-type load with a torque equation equal to: TL=1.34×10−7ω2TL=1.34×10−7ω2 N.m The fan speed range is from 500 to 1200 rpm. To achieve the required operation, the armature voltage of the motor is adjusted by a single-phase, full-wave, ac/dc converter. The input voltage and frequency to the converter are 480 V (rms) and 50 Hz. choose the motor type, show the motor rating, αα range, Supply voltage, and frequency, and any required other information Modify the design to automatically adjust the voltage drive the load within the specified speed range. show the control variable, controller type, connection, and controller weights.
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?
The torque–speed curve of a particular 10-pole induction motor is approximately linear for lowvalues of slip either side of its synchronous speed. When used as a motor on a 50 Hz supply, itsefficiency is 90% and it produces a mechanical output power of 25 kW at a speed of 550 rev/min.Estimate the power produced when the machine is connected to the same 50 Hz mains and driven bya wind turbine at 650 rev/min.
A series-connected dc motor operates at 1400 rpm from a source voltage of VT=75 V. The developed torque (load torque plus loss torque) is constant at 25 Nm. The resistance is RA+RF=0.1 Ω. Determine the value of resistance that must be placed in series with the motor to reduce the speed to 1000 rpm.
a 220v dc shunt motor takes 5a and 40a at no load and full load respectively it has an armature resistance of 0.2 ohm and field resistance of 110 ohm respectively. iron,friction and windages losses are negligible.then using among parameters find following. calculate emf at full load of dc motor