A A-connected, 25-kW, 230-V, three-phase, six-pole, and 50-Hz squirrel-cage induction motor has the following equivalent-circuit parameters in ohms per phase Y: R1 = 0.045 R2 = 0.054 X1 = 0.29 X2 = 0.28 Xm = 9.6

a. Calculate the starting current and torque for this motor connected directly to a 230-V source.

b. To limit the starting current, it is proposed to connect the stator winding in Y for starting and then to switch to the A connection for normal operation.

(i) What are the equivalent-circuit parameters in ohms per phase for the Y connection?

(ii) With the motor Y-connected and running directly off of a 230-V source, calculate the starting current and torque.