Which of the following conditions does NOT lead to a trip of the MFP?

The condition that does not lead to a trip of the Main Feedwater Pump (MFP) is sufficient steam supply. In the context of feedwater pumps, sufficient steam supply indicates that there are adequate conditions for the pump to operate efficiently and effectively. The presence of sufficient steam supply typically ensures that the system maintains the necessary pressure and flow required for optimal performance of the pump.

When looking at the other conditions, low lube oil pressure can compromise the lubrication of the pump, leading to potential overheating and damage, which would necessitate a trip to protect the equipment. High feed pump discharge pressure could indicate a blockage or malfunction in the system, thereby causing a trip to avoid damage. Additionally, low exhaust vacuum can result in inefficient operation of the system and could also prompt an automatic trip to prevent adverse effects on performance.

Thus, sufficient steam supply is a positive condition, while the other listed conditions represent potential risks to the operation of the MFP that would trigger a trip.