Question.

The rudder motor of a Ward-Leonard type steering gear is a compound-wound machine, details of which are given below. From this information find: (a) armature current, (b) the torque developed by the motor, (c) output power of motor. Armature — volts 90, resistance 0.02880, rev/min 370. 1R drop over armature may be taken as 8.5V. Shunt field — separately excited from 110V supply, resistance 65Q, turns per pole 1000. Series field — separately excited by prime mover line current of 325A, turns per pole 11. Torque Nm = (armature current (A) x flux (kWb) per pole x 10-4 X 6.8) = 15. M.M.F per pole (At)

3000 3500 4000 4500 5000 5500 6000 Flux per pole (kWb)

2500 2700 2860 2990 3100 3190 3275