A 8.8 kW, 220 V, 1200 rpm dc shunt motor has armature resistance of 0.1 Ω and field resistance of 100 Ω. The rotational loss is 2200 W. Compute: a) The rated load torque on the shaft. b) The armature current.
I have worked out the rated load torque which the answer is 70Nm. However, i have no idea of how to determine the armature current. I know output power is equal to developed power minus rotational loss. Hence, I got developed power as 11000W. And developed power is equal to Ea(Ia). How to get Ea without the total current given?