ES ELECTRICAL Flashcards
(14 cards)
What happens to a non-ES selected MUP when normal feeder breakers open?
It trips because it is not ES selected, even if the diesel keeps the 4kV bus energized.
What position is the 43 Selector Switch captured in?
The “B” position.
Why can 4kV ES buses not be aligned to the same auxiliary transformer?
During bus loading, TMI could separate from the grid.
What do potential transformers do in the ES electrical system?
They initiate protective tripping on undervoltage and monitor voltage, interlocked with the switchgear door.
What does the Bell Alarm indicate?
It actuates on an overcurrent breaker trip.
What is the requirement for NR-P-1B ES selection?
It must be powered from the same side as 1C ESV (NR-V-1B supply).
If 1P and 1S are cross-tied, how is the load on the side without direct 4160V power calculated?
What are the output limits for EG-Y-1B?
2.9 ± 0.1 MW and 0.5 - 1.0 MVARs.
What is the seismic qualification for 4kV breakers?
6 breakers racked in 1D and 5 breakers racked in 1E.
What are the voltage thresholds for degraded and loss of voltage per T.S. 3.5.1?
Degraded voltage = 3760V for 10 seconds, loss of voltage = 2400V for 1.5 seconds.
What is the LCO action for one or both ES buses being inoperable?
1 INOPERABLE = 72 hours LCO, BOTH INOPERABLE = 1 hour 3.0.1.
What is the sequence for closing the 1N cross-tie breaker?
The high side breaker must be closed with the cross-tie open, and the normal supply must be open with the 1N-12 breaker closed.
What is the voltage range for the Load Tap Changer?
4162-4218V
What is the behavior of the 1C ESV MCC during ES?
It is power-seeking but blocked on ES with manual reset.
