1. EDG Auto Starts
    • All 4 start on LOCA (either div, either unit)
    • LOOP

    • 2 divisional: Loss BOP bus
    • BOP bus U/V AND UAT U/V with UAT supply breaker open

    • 1 single DG: Loss E-bus
    • bus U/V OR M/S and x-tie breakers open
    • AND DG in auto or not running
  2. DG trips in AUTO
    Low lube oil pressure


    Generator Lockouts (diff, loss field, reverse power)

    Barring Gear Engaged
  3. Additional DG trips in manual
    High lube oil temperature 190oF

    High jacket water temperature 200oF

    Low jacket water pressure 21 psig
  4. What DG trips are bypassed on start?

    For how long?
    • For 45 seconds:
    • Lube oil pressure

    JW pressure

    Overspeed (electrical)
  5. What does Jet Assist provide?
    injects starting air directly into intake manifold during LOCA load sequencing
  6. When does Jet Assist occur?
    4 seconds duration from RHR pump start (t=10 - t=14) IF:

    • DG running in AUTO
    • output breaker closed
    • run controls energized
    • RHR pump breaker (same unit only) closed
  7. DG Governor operation in AUTO
    Isochronous 60 Hz w/varying load

    NO load sharing capabilities!
  8. DG Governor operation in Manual
    Droop of 3Hz total

    • allows load sharing
    • must manually adjust speed with varying load
  9. DG Mechanical governor
    backs up AUTO governor, limiting to 61 Hz

    If LOOP while full load testing, DG will swap to AUTO and mech gov will limit speed, but cannot take credit for mech gov reliability so DG not in "ready to load" condition

    therefore DG INOP in manual
  10. To swap DG from AUTO to MAN
    expect up to 3Hz drop(full load)

    must raise frequency or lower load to prevent EPA breaker trip (57.7Hz)
  11. What are AUTO close permissives for DG output breaker?
    • Bus undervoltage
    • Bus stripped (except 480V E-bus feed)
    • .75 second trip from AUTO start signal clear

    • assuming (always req'd to close bkr)
    • DG at rated speed and voltage
    • Electrical lockouts clear
  12. What is required to manually close DG output breaker?
    sync scope on (local or same unit RTGB)

    for opp unit, must have bus U/V

    assuming (always req'd to close bkr)DG at rated speed and voltageElectrical lockouts clear
  13. To close DG output breaker locally (ASSD)
    local keylock switch in isolate

    sync scope on AND Bus U/V
  14. DG output breaker trips
    • Electrical lockouts
    • Any AUTO start .75 sec
    • run controls de-energized (prevents reverse power)
  15. DG indications: Red "NOT AVAILABLE" light indicates what condition?
    Engine L/O relay tripped
  16. DG indications: Green "NO LOAD" light indicates what condition
    DG at rated speed and voltage
  17. Diesel AUTO STOP pushbutton
    Secures DG and energizes DG lockout relay

    • must reset locally OR
    • on an AUTO start (if no auto start previously present) OR
    • when Emergency start pushbutton depressed
  18. If EDG is running in manual and gets an AUTO start, what happens?
    • DG output breaker opens
    • E-bus strips
    • Governor swaps to isochronous
    • Tie back onto the bus ONLY if UV exists at 61Hz
  19. How is a EDG Engine Lockout reset?
    Depress reset pushbutton on (local) engine control panel
  20. How is a Diesel Generator lockout reset?
    reset at E-bus first using football switch, then reset Engine lockout locally
  21. AUTO DG lockout reset
    will reset 1 time for 1 second on an AUTO start signal or Emergency start PB used
  22. What happens on a loss of DC power to DG engine control circuits?
    Fuel rack cylinders reposition to the no-fuel position, but no trip signal

    eventually trip on reverse power
  23. DG control power comes from where?
    • normal same div, same unit
    • alternate same div, opposite unit


    recieve annunciator if EITHER norm or alt power is lost

    manual transfer (back of excitation cabinet) with mech interlock, must place DG back in auto after swapping
Card Set
systems knowledge