Example 20-4. A 200 hp (150 kW), 460 V, 3-phase, 3520 r/min, 60 Hz induction motor has a locked-rotor torque of 600 Nom and a locked-rotor current of 1400 A (same motor as in Example 20- 2). Two auto...
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...
2) A 460 V, 4-pole, 60 Hz, Y-connected, 40 hp, design class A induction motor is tested with the following results: No-load: 460 V, 8.7 A, 2500 W. 60 Hz Locked rotor: 42 V.48 A, 31 10 W. 12 Hz DC test: 24 V, 48 A Find the equivalent circuit of this motor (Ri, Ro. Xi. X. XM) and its rotational losses. (20 points) X, and A2 as functions of XL Retor Design Wound rotor Design A Design B Design...
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...
. A 460-V 460-V, 25-hp, 60-Hz, six-pole, Y-connected induction motor has the following impedanc ohms per phase referred to the stator circuit. Ri= 0.212 R2 = 0.282 X1 = 1.055 12 X2 = 1.055 22 XM = 33.9 W The total rotational losses are 1100 W and are assumed to be constant. The core loss is lumped with the rotational losses. For a rotor slip of 4% at the rated voltage and rated frequency, a) The input power b) Peony...
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...
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...
A 500 hp, three-phase, 2200 V, 60 Hz, 12-pole, Y-connected, wound-rotor induction motor has the following parameters: 5.9 0.225 Ω x, R, R',-0.235 Ω X, 31.8 Ω R""-780 Ω 1.43 Ω Calculate the following: a. Slip at maximum torque b. Input current and power factor at maximum torque c. Maximum torque d. Resistance that must be added to the rotor windings (per phase) to achieve maximum torque at starting
A 3-phase, 208 V, 60 Hz, 30 hp, four-pole induction motor has the following equivalent circuit parameters. R1 = 0.2 Ω, , , Xm = 12Ω.The rotational loss is 500 W. For a slip of 5%, calculate (a) The motor speed in rpm and radians per sec (b) The current drawn by the motor from the power supply (c) The stator cu-loss (d) The air gap power (e) The rotor cu-loss (f) The shaft power (g)The developed torque and the shaft torque (h) The efficiency of the motor Use...
The following test data apply to a 7.5-hp, three-phase, 220-V, 19-A, 60-Hz, four-pole induction motor with a double-squirrel-cage rotor of design class C (high-starting-torque, low-starting current type): Test :No-load test at 60 Hz; Applied voltage V - 219 V line-to-line; Average phase current I, nl 5.70 A; Power Pnl -380 W; Test 2: Blocked-rotor test at 15 Hz; Applied voltage V 26.5 V line-to-line; Average phase current lbl 18.57 A; Power Pbl 675 W; Test 3: Average de resistance per...
1. A 15 hp, 4 pole, 208 V, 60 Hz, Y-connected, three-phase squirrel cage induction motor has the following parameters in Ω/phase referred to the stator: R,-0.220, Xi = 0.430, X,-15.0, R2 0.130 and X2-0.430. Mechanical and core losses amount to 300 W and 200 W respectively for rated voltage. (a) The motor is fed with a 60 Hz, 208 V voltage. It runs with a slip of 4.5 %. Find the speed, shaft torque and power, efficiency and power...