When does MFP turning gear lockout occur?

The correct answer indicates that MFP (Main Feed Pump) turning gear lockout occurs when the gear fails to engage within a specified time limit, which is typically 5 seconds. This is an important safety feature designed to prevent potential damage to the equipment or unsafe operating conditions. If the turning gear cannot engage promptly, it may signify underlying issues such as mechanical faults or hydraulic control failures, warranting immediate attention to avoid further complications.

In the context of MFP operation, it is critical that the turning gear engages smoothly to ensure proper alignment and functioning of the pump during startup or shutdown sequences. Locking out the gear after 5 seconds without engagement allows operators to diagnose and rectify problems without risking harm to the equipment or personnel.

The other options do not represent the triggering conditions for MFP turning gear lockout. Disengagement of the gear is a normal part of operation and does not signify a failure; it’s designed to allow the pump to transition between different states safely. Maintenance activities could involve locking out equipment as a safety precaution, but not specifically related to the turning gear's operation in the context of engagement failure. Lastly, pressure limits generally relate to operational safety standards but do not specifically dictate lockout conditions for the turning gear itself.