Which condition can cause a single MFP trip?

A single main feedwater pump (MFP) trip can occur due to low lubrication oil pressure on the bearings of the feedwater pump. This condition is critical because the lubricant is necessary for reducing friction and wear between moving components. When lubrication oil pressure drops too low, it may not adequately provide the necessary film of oil to prevent metal-to-metal contact, which could lead to severe damage to the bearings and potentially result in a catastrophic failure.

The integrity of the lubricating system is essential for safe operations, as it directly impacts the performance and reliability of the pump. Thus, when low lube oil pressure is detected, the trip system activates as a protective measure to prevent extensive damage and ensure the safety of the equipment and personnel.

Other conditions, while potentially problematic, do not directly trigger a trip of the MFP in the same critical manner as low lubrication oil pressure. Recognizing the importance of lubrication in the operation of machinery helps underscore why low lube oil pressure is a valid reason for an MFP trip.