diesels. Flashcards
what is the capacity of the fuel oil storage tanks?
two tanks containing 26,500 gallons each.
how long can the EDGs operate to supply power?
seven days.
4200KW requires 50,000 gallons of fuel over seven days.
what is the diesel rated for?
- 4430KW
- 0.8pf
- 5538KVA
how long can the EDGs be operated at 110% overload? (4873KW)
2 out of 24 consecutive hours.
how long can the EDGs be operated at 120% overload? (5316KW)
30 minutes (without special inspection).
what are the auto start signals for the diesels?
- LOP
- degraded voltage
- LOCA
what are the signals for a LOP auto start?
both incoming feeder voltages <92% AND
bus voltage <70%
what is the condition the causes a degraded voltage auto start?
both incoming feeders <92% for 20 seconds.
what are the signals that cause a LOCA auto start?
core spray logic
RPV level -129” (level 1)
OR
drywell pressure 1.68#
OR
manual core spray initiation.
what causes the regular lockout (86R)?
- generator differential overcurrent
- low lube oil pressure
- overspeed (engine)
- bus differential overcurrent
- emergency stop pushbutton (140 sec lockout, then engine reset, then 86R).
what causes the backup lockout (86B)?
- generator phase differential overcurrent
- generator phase overcurrent.
what causes the test lockout?
- reverse power
- bus overcurrent
- low field current
- overexcitation
what occurs at 0 RPM upon EDG start?
- cranking cycle timer initiate
- SACS cooling water valves open
- low air start pressure alarms lockout
what occurs at 95 RPM upon EDG start?
starting air shutoff.
what occurs at >365 RPM upon EDG start?
- starting air shutoff
- field flash (again)
- low lube oil pressure trip enabled (indication after 7 second time delay
when is the EDG ready to load permissive?
> 3950VAC and >57Hz.
what happens at >125RPM upon EDG start?
- starting air shutoff (again)
- D/G room recirc fan armed
- “diesel running not loaded’ light energized
- engine run timer starts
- jacket water & LO high temp alarms disabled
- motor driven fuel oil pump armed
- motor driven rocker arm prelube pump armed
- LO keep warm heater shutdown
- JW keep warm pumps & heaters shutdown
- generator space heater shutdown
- exciter field flash circuit activated
- low starting air pressure alarm reactivated
-cranking timers reenergized
what does 125VDC provide for the EDGs?
125VDC provides control power for the air solenoids to start the diesel.
without 125VDC, the diesel will not start.
what are the EDG recirc fan trips?
- overcurrent
- undervoltage
- low flow
- CO2
what is required for the EDG to be in auto start?
- remote/local/maintenance in remote
- normal/emergency takeover in normal
- shutdown relay not energized
- diesel generator lockouts reset
- barring device not engaged
- start failure relay not energized
- 125VDC control power available
what does the anti-pumping circuit do?
if a LOP were to occur within 2 seconds of a diesel breaker closure, the breaker may not reclose after it trips; the operator will have to press the trip pushbutton and close the breaker.
what cools the diesels and what is required if you do not have cooling?
SACS through diesel heat exchangers. air intercooler -> jacket water-> lube oil.
upon loss of SACS, unload and secure diesel IAW AB.COOL-002.
why is the rocker arm lube oil system seperate?
to prevent fuel oil contamination of the MLO system. makeup to the rocker arm lube oil system is provided from the MLO system.
what does the starting air system provide air for?
- starting
- control
- shutdown
what is the purpose of the woodward governor?
it’s a mechanical governor that is set higher than electrical; electrical fails high and mechanical will take over.
how many starts is each air receiver tank capable of?
5 starts.
what is required after a lockout to reset it?
the “engine reset” pushbutton must be pressed prior to resetting the lockout; must wait 140 seconds, buttons pressed locally, then 86 device could be reset.
how is lube oil makeup controlled?
a solenoid valve that will fail closed on a loss of power; can be overridden locally with a control knob at the base of the valve.
how long does it take for the diesel to start and come up to rated voltage?
10 seconds; 13 seconds are allowed for signal processing time.
what does the diesel breaker failure protection do?
trips the diesel & trips the normal and alternate feeder breakers.
what does a LOCA start do?
- all NORMAL stops disabled (emergency still works)
- test lockout relay disabled
- governor shifts to isochronous (4160V) and voltage control is disabled (10C651)
- opens EDG output breaker if running in TEST.
what are the positions of the local engine control switch and what do they do?
- remote- control from remote engine control panel or the control room.
- local- control locally; all auto starts disabled.
- maintenance- control locally; all auto starts and excitation disabled.
- auto (MCR bezel)- if out of auto, no MCR starts available.
what does the remote generator EMERGENCY TAKEOVER do?
- enables control of diesel and breaker from remote generator and engine control panels.
- diesel WILL NOT RESPOND TO A LOCA. (LOP responds to <70% bus voltage signal only).
what does the diesel have to be in during a normal load test surveillance?
droop. for proper load sharing characteristics.
what must you do if the flame arrestor is damaged?
inspect to ensure the fuel transfer pumps work.
