- A 4 Pole 50 Hz 3 Phase Induction Machine Is Rated At 1480 Rpm And 240 V A Blocked Rotor Test Yields The Following Me 1 (58.66 KiB) Viewed 54 times
A 4 pole, 50 Hz, 3-phase induction machine is rated at 1480 rpm, and 240 V. A blocked rotor test yields the following measurements: three-phase power 460 W, line current 10.5 A and line to line voltage 58 V. A no-load test yields: 300 W, 6.0 A, 240 V. A DC resistance test yields values of 70 ohms for stator winding resistance (per phase, Y equivalent). Assume the approximate equivalent circuit (Rc and Xm branch connected directly across the motor terminal): 1) Calculate the synchronous speed in rpm, the rated slip in percent, and the rated speed in rad/sec. 2) Calculate the series impedance (R2', X2') in ohms. 3) Calculate the shunt elements (Rc , Xm) in ohms. 4) Calculate the equivalent load resistance (R = R' [1-s]/s) for a speed of 1480rpm. 5) Predict the output power and torque corresponding to 240 V and 1480 rpm (rated conditions).