EMERGENCY DIESEL GENERATORS (861) Flashcards
(28 cards)
What does the UNIT switch on the EDG do?
It sets zero speed droop and shorts out voltage droop to ensure the EDG does not carry excessive VAR loading.
What conditions must be met for the “Ready to Load” light to turn on?
Frequency >59 Hz and voltage >4100V.
What trips are blocked on ES for the EDG?
Low lube oil pressure, start failure (<250 RPM @ 9 sec or <6# LO), high crankcase pressure, and STOP buttons in MCR and at the engine.
What trips are valid on ES for the EDG?
Low lube oil pressure running (<16# after EDG running), 86G fault relay, engine overspeed, and emergency local trip.
What are the operability requirements for the EDG?
Starting air accumulator (>175#), AH-E-29A/B operable, fuel inventory (>25K gal in DF-T-1), and fire protection service water.
What is the minimum starting air pressure for the EDG to meet its 10-second loading mission time?
175#.
What happens to the starting air solenoids (EG-V-16A/B/C/D) on loss of power?
They open to inject air into the pistons, allowing the EDG to start.
What actions can be taken to stop a runaway diesel?
Close air intake valves (EG-V-15A/B) or inject CO2 into the intake/diesel itself.
What interlock prevents closing the EDG breaker in parallel?
The interlock prevents closing the breaker 15 minutes past the hour; the synchronization window is 2 to 5 minutes after the hour.
What must be adjusted if the “Ready to Load” light does not come on after a LOOP?
The local ES voltage rheostat must be adjusted.
What happens if the AUTO-STANDBY manual-exercise switch is in MANUAL exercise?
The diesel will not auto-start.
What is the rated power output of the EDG?
3.0 MW.
What must be done if the EDG starts at 60.8 Hz, 4275V, and 3.3 MWe?
ES loads on the diesel must be reduced.
What happens during a diesel quarterly ES test switch in Group 1 position?
If a LOOP occurs, the diesel starts only on the “A” relay.
What prevents the SBO diesel from cross-tying to multiple 4kV buses?
52 breaker interlocks.
How is the EDG speed increased when starting locally?
Using the “Speed Adjusting Knob” at the engine governor.
What happens if EG-Y-1B is OOS and an opposite train ES component is declared INOP?
The most limiting specification is 3.0.1.
What happens if EG-Y-1A is INOPERABLE and EG-Y-1B has an identical component but its condition is undetermined?
No additional Tech Spec actions are required due to the low probability of an event occurring during testing.
How is the SBO diesel prevented from cross-tieing to more than one 1C/1D/1E bus?
By looking at 52 contacts on the tie breakers.
What happens if EG-Y-1B is in MANUAL EXERCISE mode in the control room?
EG-Y-1B would fail to automatically start.
What occurs when EG-Y-1B is loaded for monthly surveillance at 1.5 MWe and the “A” aux transformer faults and trips?
The 1E bus stays energized, and MU-P-1B trips because it only looks at the normal feeder breaker.
What might lower than expected Hz on the 1E bus during a LOOP indicate?
The speed droop setting was left at 70 on the governor.
What protective feature prevents closing the EDG breaker in parallel with the synch scope at 15 minutes past the hour?
The synch scope window is limited to 2 minutes before to 5 minutes after the hour.
How is the EDG speed increased when starting locally?
Using the “Speed Adjusting Knob” at the engine governor.
