5. a) A 900V DC series motor is rated at 388 HP, 3000 RPM. It has an armature resistance of 0.5 2 and a field resistance
Posted: Thu May 26, 2022 10:16 am
5. a) A 900V DC series motor is rated at 388 HP, 3000 RPM. It has an armature resistance of 0.5 2 and a field resistance of 0.02 2. The machine draws 450 A from the supply when delivering the rated load. The magnetic saturation is to be ignored. Determine:- (1) The rated developed torque [4 marks] [3 marks] (ii) The rated efficiency (iii) The rotational losses at rated speed [2 marks] (iii) The speed when the load is changed, causing the line current to drop to 100A. [5 marks]