A 440 V, short shunt compound motor has Ra = 0.75 ?, Rs = 0.5 ?, If = 2A. The full load speed and current are 1800 rpm and 27 A respectively. The motor takes 5 A at no load.
a. What are the efficiency and the horse power rating of the motor?
b. Draw (with values) the power flow diagram of the motor.
c. If at no load, the flux drops to 75% of full load value, determine the no load speed of the motor. Assume that the rotational loss is constant.