Plant is at 100%, performing “Turbine Overspeed Protection System Test”.
Visual inspection of one of the main turbine valves shows the valve closes significantly faster during the last portion of its closure stroke.
Why was there a different in the valve’s stroke time during the performance test?
this occurred since the valve piston loses all hydraulic pressure during the final 5% of the closure stroke to simulate a trip signal response
Which of the listed PPE is NOT required to be worn by the PEO?
full face respirator
EHC fluid is leaking down to the TB 14’ elv.
where should the leaking fluid be directed?
fluid should be contained and collected, without allowing it to drain to the floor drains, sumps, or oil-water separators
A PEO is operating EHC system bypass isolation valve. What requirement exists after the PEO completes the valve operation?
the valve hand wheel needs to be removed
What is one special precaution that exists with EHC fluid that is not as big a concern with lube oil?
human contact, EHC more toxic
What is the normal EHC system pressure, and at what pressure will the standby EHC pump auto start?
normal EHC pressure is 1600 psig. The standby EHC pump will auto start at 1300 psig
What is the required operating temperature of EHC fluid to ensure proper operation of main turbine controls?
85-110 F
What indications provided to inform when alumina desiccant needs to be replaced?
turns pink
Which statement is correct concerning the EHC supply pumps?
the standby pump will auto start if the discharge header pressure decreases to 1300 psig
The purpose of the EHC accumulators is to provide which the following?
an immediate reserve of EHC fluid for transient flow requirements
The plant is decreasing load at 5% per minute.
How is EHC system pressure maintained during the load decrease?
The EHC pump’s pressure compensator will automatically adjust the stroke of the pump
