A three-phase, 220-V, 60-Hz, four-pole, wye connected induction motor has a per-phase stator resistance of 0.5 . The following no-load and blocked rotor test data on the motor are given:

• No-load test: line-to-line voltage 220 V, total input power 600 W, of which 200 W is the friction and windage loss, and line current 3 A

• Blocked-rotor test: line-to-line voltage 35 V, total input power 720W, and line current 15 A

(a) Calculate the parameters of the equivalent circuit.

(b) Compute the output power, output torque, and ef?ciency if the machine runs as a motor with a slip of 0.05.

(c) Determine the slip at which maximum torque is developed, and obtain the value of the maximum torque.