A 480V,60Hz,50hp, three-phase induction motor is drawing 60A at 0.85PF lagging. The stator copper losses are 2kW, and the rotor copper losses are 700W. The friction and windage losses are 600W, the core losses are 1800W, and the stray losses are negligible. Find the following quantities: (a) The air-gap power PAG (b) The power converted Pconv (c) The output power Pout (d) The efficiency of the motor Solution To answer these questions, refer to the power-flow diagram for an induction motor (Figure 7-13). (a) The air-gap power is just the input power minus the stator l2R losses. The input power is given by