A 4-pole, 3-phase, 50 Hz induction motor has a voltage between slip-rings on open-circuitof 520V. The star-connected rotor has a standstill reactance and resistance of 2 2 and 0.4 2per phase respectively. Determine: i) The Maximum torque. ii) The ratio of starting torque tomaximum torque. iii) The speed at half-load if full-load speed is 1425 r.p.m.

Answered: Image /qna-images/answer/d6c1bead-169c-4b59-af8e-ccc6fd638ccc.jpg

A 4-pole, 3-phase, 50 Hz induction motor has a voltage between slip-rings on open-circuit of 520V. The star-connected rotor has a standstill reactance and resistance of 2 Q and 0.4 2 per phase respectively. Determine: i) The Maximum torque. ii) The ratio of starting torque to maximum torque. iii) The speed at half-load if full-load speed is 1425 r.p.m. -----

A 4-pole, 3-phase, 50 Hz induction motor has a voltage between slip-rings on open-circuit of 520V. The star-connected rotor has a standstill reactance and resistance of 2 Q and 0.4 2 per phase respectively. Determine: i) The Maximum torque. ii) The ratio of starting torque to maximum torque. iii) The speed at half-load if full-load speed is 1425 r.p.m. -----

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

L-1). The 3-phase wound-rotor induction motor has .... . a) high starting torque b) low starting current c) both "a" and "b" d) neither "a" nor "b" L-2). The 3-phase wound-rotor induction.........a) motor has a wire wound rotor b) motor's rotor can be connected to an external resistive load by way of slip rings and brushes c) motor requires more maintenance than the 3-phase squirrel-cage induction motor d) all of the above L-3). The 3-phase wound-rotor induction motor's rotor circuit's resistance should be adjusted so it is__________ during starting. a) low b) high c) either "a" or "b" d) neither "a" nor "b" L-4). Will a 3-phase wound-rotor induction motor start with no external circuit connected to its rotor leads? a) yes b) no
f The simplicity in construction of a single-stack VR step motor is due to.... 1. Low number of phases, 2. Low used voltage, 3. N, N, 4. Bidirectional rotation, 5- None of previous. g- The synchronous inductor motor has the ability to step when the phase windings are .............. 1. Connected in parallel, 2. Connected in series, 3. Connected in star, 4. Energized with dc, 5- None of previous. h- The speed of multiple-stack VR step motor with continuous stepping is 3.120, 4.5 5- None of previous. 60f T T Resonance conditions distort the torque/speed curve causing a Drop, 3. Ripple, 4. Fluctuation, 5- None of previous. ********** 1. 120f 2p 2. 60f 2p " in torque. 1. Increase, 2. j- The frequency of armature current in 1-phase series motor is 1. =f, 2. f, 4. Zero, 5- None of previous. (f is the supply frequency)
Type your question here A 6- pole, 50 Hz 3-phase induction motor has a full load slip of 4 percent. The rotor resistance and reactance per phase are 0.24 2 and 2 2 respectively. Calculate: a) The speed at the maximum torque and full load torque. b) The resistance to be added to the rotor circuit to obtain 60% of the
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 obtainmaximum starting torque.b) Compare the starting torques and starting current with and without the added capacitance in theauxiliary winding circuit when operated from a 120V, 60Hz supply
An 3-phase induction motor(IM) has full load slip = 0.5%. If the rotor circuit resistance is increased so that R2new =2R2old, then the slip at which the motor develops the same full load torque is=.. * ......
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
The rotor of a four-pole, 50 Hz slip-ring induction motor has a resistance of 0.2 0 per phase and runs at 1425 rpm at full-load. Determine the external resistance per phase which must be added to reduce the speed to 1200 rpm, the torque remaining same in both the cases.
4-25- six pole. Three phase. 40-hp, 60-Hz induction motor has an input when loaded of 35 kw , 51A, 440V And a speed of 1152 rpm ,when uncoupled from the load .the readn are found to be 440-v ,21.3 A ,2.3 Kw , and 1199 rpm,the resistance... Between terminal for the stator winding is 0.25 2 for a Y-connection , the stator core losses and the rotational losse are.determine: a-the power factor b-the horspower
Problem 3 A 3-phase 2-pole induction motor is rated 190 V, 60 Hz, it is connected in Y, and has R2 = 6.6 Q, R1= 3.1 Q, Xm X2 = 10 2, and X1 = 3 Q. It is operating from a variable speed variable frequency source at a speed of 1910rpm, under a constant V/f policy and the developed torque is 0.8Nm. What is the voltage and frequency of the source? 190 2,
B/ Fill in the blanks: TV ezur 1- In a three-phase induction motor iron losses in stator will be..... that in rotor. 2- In three-phase induction motors sometimes copper bars are placed deep in the rotor to........... 3- Blocked rotor test on induction motors is used to find out. R..., ke, X. 4- The maximum torque in an induction motor depends on .............and .....
1. A certain 60Hz, four-pole split-phase induction motor spins at 1760rpm when running with no torque load. Find its slip at no load. A. 1800 rpmB. 90 rpmC. 1150 rpmD. 40 rpm Determine the percent slip of # 1 at no load. A. 5%B. 2.27%C. 5.11%D. 2.22%
A three-phase 2Jhp 220V 60HZ six pole Y-connected squirrel-cage induction motor has the following parameters per phase referred to the stator: R1 = 0.1262, Ř2 = 0.0940, Xsc = 0.462 and Xm=9.82. The rotational losses are 560W. For a slip of 3%, find: %3D a) The shaft speed. b) The line current and power factor. c) The output horsepower and shaft torque. d) The efficiency.