When taking an alternator off the line, what should happen to the driving torque of the prime mover?

When an alternator is taken off the line, the driving torque of the prime mover should be reduced. This is because the alternator, when connected to the electrical load, requires a specific amount of torque to generate electrical power efficiently. Once the alternator is disconnected or taken offline, it stops supplying power, and the load on the prime mover decreases significantly.

Reducing the driving torque is essential because maintaining excessive torque when the alternator is no longer generating power could lead to inefficiencies, potential damage to the equipment, and unnecessary stress on the prime mover. Properly managing the torque helps to ensure smooth operation and prevents mechanical issues that could arise from abrupt changes in load or operational status.