Example: Calculate the require resistance for a four-step starter to limit the starting current of a DC shunt motor to 150% of rate current. Assume that all four steps have an equal resistance value. The motor has rating as 10 Hp, 240 Volts, 860 rpm. And armature resistance is 0.1 Ohms, the overall efficiency 90%. Determine at each speed of the starter resistance must be take into the starting circuit to maintained the rate value during start up period. Assume that the field current is negligible compared to rate armature current