4) Given in a Induction Motor
V2 = 460 volts
Stator frequency, f = 50 Hz.
Poles = 2
Slip = 5% = 0.05.
Ns = 120f / P = (120 ) (50 ) / 2 = 3000 RPM = Sychronous frequency.
also given, friction and windage losses (or) mechanical losses
Pme = 700 w.
core losses = 600 w.
(a) Shaft speed in RPM.
Shaft speed (or) Rotor speed, Nr = Ns ( 1 - s)
= 3000 ( 1 - 0.04 )
Nr = 2850 RPM
(b) Output power in horse power.
we have , 1 British horse Power = 0.746 kw.
1 Metric horse Power = 0.785 kw (mostly preferred)
Out put power , point = 50 kw
= 50 / 0.735
Pout = 68 HP
in MHP
Out put power , point = 50 kw
Pout = 50/ 0.746
Pout = 67 HP in BHP.
4. A 50-kW, 460-V, 50-Hz, two-pole induction motor has a slip of 5 percent when operating...
A 4 phase, 460 V, 60 Hz, 26.8 hp, 4 pole, Y-connected
induction motor draws 25 A at a power factor of 0.9 lagging. Core
loss is 900 W, stator copper loss is 1100W, friction and winding
losses are 300 W, and stray loss is neglected. The machine shaft
rotates at 1738 rpm. Calculate the air gap power and output load
torque
- [Induction Motor - 15 points) A three-phase, 460 V, 60 Hz, 26.8 hp, 4-pole, Y-connected induction motor...
The input power to a 480V, 3 phase, 6 pole, 50 Hz induction motor is 75kW with a line current of 75A and runs at a slip of 2.5%. If the stator core loss is 2 kW, windage and friction loss is 1.2 kW, and the stator resistance per phase is 0.16 ohm. Calculate: a. Power supplied to the rotor (Air gap power) b. Rotor copper loss c. Shaft power d. Efficiency of the motor e. Shaft torque f What...
Please solve this question. Thank you.
A two-pole, 75kW, 440 V, 50 Hz, Y-connected, three-phase squirrel cage induction motor has the following parameters, in Ω/phase referred to the stator: R1-0.075, XI 0.17, xm-72, R2-0.065 and X-0.17. Its rated slip is 4%. Assume that the mechanical losses are 1 kW and the core losses are 1.1 kW. Compute: a. The rated input current b. The rated power factor. c. The pullout torque d. The induced and load torques at rated conditions....
6. [Induction Motor - 15 points] A three-phase, 460 V, 60 Hz, 26.8 hp, 4-pole, Y-connected induction motor draws 25 A at a power factor of 0.9 lagging. The core loss is 900 W, stator copper loss is 1100 W, friction and windage loss is 300 W, and stray loss is neglected. The machine shaft rotates at a speed of 1738 rpm. Calculate the air gap power and output load torque.
A 3-phase, 460 V, 1740 rpm, 60 Hz, 4-pole wound-rotor induction motor has the following parameters per phase: R1 = 0.25 Ω, ' 2R = 0.2Ω, ' 1 2 X = X = 0.5Ω, 30 m X = Ω. The rotational losses are 1700 W. With the rotor terminals short-circuited, find: 1. at starting: • current when started direct on full voltage, • a torque 2. at full load: • slip • current • ratio of starting current to full-load...
4.6. A 460-V, 75 kW, 4-pole, delta-connected, 60-Hz, three- phase induction motor has a full-load slip of 5 percent, an efficiency of 92 percent and a power-factor of 0.87 lagging at full-load. At start-up, the motor develops 1.9 times the full load developed torque but draws 7.5 times the rated current at the rated voltage. This motor is to be started with an auto- transformer reduced-voltage starter. Assume the stator resistance and the stator core loss to be negligible. Calculate...
Name: 23. A 3-phase, 5000 hp, 6000 v,60 Hz, 12-pole wound-rotor induction motor has the 1, resistance between stator terminals-o12 Ω 2. resistance between rotor slip-rings-0.0073 Ω 3. windage and friction losses-51 kW following characteristics 4. iron losses in the stator-39 kW 5. locked rotor current at 6000 V-1800 A 6. active power to the stator with rotor locked 2207 kw Calculate under full-load voltage locked-rotor conditions a. Reactive power absorbed by the motor b. FR losses in the stator...
5 Marks) A 4-pole, 3 phase, 50 Hz, 230 V induction motor. Each phase of rotor winding b) has one-fourth the number of turns of each stator. The full-load speed is 1,455 rpm. The rotor resistance is 0.3 Ω and rotor standstill reactance is 1.0 Ω per phase. The rotor and stator windings are similar. Stator losses are equal to 50 Watts. Friction and windage losses are equal to 30 W. Calculate ) Blocked rotor voltage per phase. 2 Marks)...
6. A 3-phase 2.2 kV 25 Hz squirrel cage induction motor draws a line current of 224 A and a total power of 777 kW when operating at full load. The full-load speed is 245 rpm. The stator is wye connected and has an effective resistance per phase of 0.125 Ω. The stator iron (core) loss is 8.88 kW; friction and windage losses are 4.54 kW. Calculate at full-load conditions: b. power supplied to the rotor, a. the power factor;...
5. A 208-V four-pole 60-Hz Y-connected wound-rotor induction motor is rated at 30 hp. Its equivalent circuit components are R=0.100 Ry=0.070. X - 10.00 R = 250 X; -0.2100 X=0.21002 Praw=500 W P =0.5% of input at full load For a slip of 0.05, find (a) The line current (b) The induced voltage in the rotor (c) The stator power factor (d) The rotor power factor (e) The rotor frequency (f) The stator copper losses (g) The core loss (h)...