The timer element of a reverse power relay cannot be energized unless what condition is met?

Correct Answer: Option D — the power flow is the same as the tripping direction

Reverse power relays protect generators from motoring. The timer element prevents nuisance tripping during transient power swings. It only initiates the trip sequence when the power flow direction is confirmed as 'reverse' (from the bus to the generator), indicating the prime mover has failed to provide sufficient torque.