Question 55Motor Plants - QMED

You are correct, the answer is D) battery power direct current. Auxiliary diesel engine electric starting motors use battery power direct current (DC) because this type of power source provides the necessary high amperage, low voltage electricity required to crank and start the diesel engine. The battery bank stores the DC power that is then delivered to the starter motor to turn over and start the engine. The other options are incorrect because: A) low amperage, high voltage AC power would not provide sufficient current to the starter motor, B) alternating current transformers do not output the required DC power, and C) 400 cycle per second motor-generator power is not the typical power source used for diesel engine starters.