A three-phase, 2200-V, 60-Hz, delta-connected, squirrel-cage induction motor, when started at full rated voltage, takes a starting current of 693 A from the line and develops a starting torque of 6250 N · m.
(a) Neglect the impedance and the exciting current of the compensator. Calculate the ratio of a starting compensator (i.e., an autotransformer starter) such that the current supplied by the 2200-V line is 300 A. Compute the starting torque with the starting compensator.
(b) If a wye-delta starting method is employed, find the starting current and the starting torque.