Question 575Steam Plants - Assistant Engineer

70% to pass

To test an automatic low lube oil pressure trip on an idling turbo-generator and at the same time prevent the chance of bearing damage, you should _______________.

Aactuate the over speed trip, making a note at what pressure the oil is dumped from under the operating piston

Bsecure the steam supply valve to the throttle valve and observe the oil pressure as the throttle trips during the slowdown and ensure a supply of oil with the hand or standby pump when the pressure drops to 2-3 psi

Censure the standby lube oil pump, if so equipped, is properly lined up and set in the 'auto' mode, or the hand pump is being operated and then actuate the emergency trip

Dclose the generator steam throttle valve and then ensure a supply of oil through the hand or standby pump when the pressure drops to 5-6 psi

AI Explanation

The correct answer is B. To test an automatic low lube oil pressure trip on an idling turbo-generator and prevent bearing damage, you should secure the steam supply valve to the throttle valve and observe the oil pressure as the throttle trips during the slowdown. Ensure a supply of oil with the hand or standby pump when the pressure drops to 2-3 psi. This is the correct approach because it allows you to test the low lube oil pressure trip without risking bearing damage by completely shutting off the steam supply. The other options are either not directly related to testing the low lube oil pressure trip (A and C) or do not provide a sufficient oil supply when the pressure drops (D).