Induction Motor Power Problem
20 kW is the rated mechanical output power. The actual operating power depends on the load. Subtract the core loss and the stator copper loss to get the air gap power (the power transferred from the stator to the rotor across the air gap). Subtract the rotor copper loss, friction and windage (air drag) losses from the air gap power to get the mechanical power delivered to the load in watts (746 W = 1 Hp).

You are correct; n &lt; ns indicates operation as a motor. If n > ns, you would add the losses to the electrical power instead of subtracting and the electrical side figures would be the output and the mechanical side would be the input.