A three-phase, 7.5Hp, 230V, 60Hz, Delta connected induction motor was tested and give the following input data: No load Test: I = 10A P = 650W slip = 0.8333% Load Test: I = 19A, P = 6800W slip = 3% Resistance test between two stator terminals: Vdc = 9V , Idc = 20A Assume K = 1.5 Determine the efficiency of the motor during the load test

A three-phase, 7.5Hp, 230V, 60Hz, Delta connected induction motor was tested and give the following input data: No load Test: I = 10A P = 650W slip = 0.8333% Load Test: I = 19A, P = 6800W slip = 3% Resistance test between two stator terminals: Vdc = 9V , Idc = 20A Assume K = 1.5 Determine the efficiency of the motor during the load test

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.

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A 110 V, 60 Hz, 6 – pole single phase induction motor 1/3 hp has the following equivalent circuit impedances: RI = 1.52 ohm, R2 = 3.13 ohm and x1 =2.10 ohm, x2 =1.56 ohm. Xm=58.2 ohm, The Friction, windage and stry losses =16W, the core loss = 35 W, For a slip of 0.05, calculation (a) input current, (b) power factor, (c) developed power, (d) output power, (e) speed (f) in put power (g) air gab power (h) T ind (i) T load 6) efficiency.
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A 440 V, 22.5-hp, 50 Hz, 3-phase, 4-pole, star-connected induction motor has the following impedances in ohms per phase referred to the stator circuit: R1 = 0.552X, = 1.1050Ra = 0.350X2 = 0.4562 Xy = 27.10 The total rotational losses are 1105 W and are assumed to be constant. The core loss is lumped in with the rotational losses. For a rotor slip of 2.3% at the rated voltage and rated frequency, d) Electrical power,e) Output power,f) Efficiency.