EDG - .5 Flashcards
EDG Fuel specs.
Each EDG has two fuel oil storage tanks – 26,500 gallons each. Seven days at 4200KW requires 50,000 gallons of fuel.
EDG Rating
- Rated – 4430KW @ 0.8Pf 5538KVA
- 110% Overload (4873KW) can be maintained for 2 out of 24 consecutive hours
- 120% Overload (5316KW) can be maintained for 30 minutes.
Auto-start signals.
- LOP - Both incoming feeder voltages <92% AND
Bus voltage <70%. - Degraded Voltage - Both incoming feeders <92% for 20 seconds.
- LOCA - Core Spray logic
RPV Level -129” OR
Drywell Pressure 1.68psig OR Manual Core Spray Initiation
EDG BKR Close permissive.
- Diesel ready for Load - Frequency >57Hz (95%)
Voltage >3950V (95%) - Switchgear - Both Normal and Alternate feeder breakers open
- Bus voltage <70%
- DG Lockout Relays reset
Regular Lockout Relay (86R)
- Generator differential o/c
- Low Lube Oil Pressure
- Overspeed (engine)
- Bus differential o/c
- Emergency Stop PBs
Backup Lockout (86B)
- Generator Differential o/c
- Generator Phase o/c
Test Lockout (86T)
- Reverse Power
- Bus Overcurrent
- Low field current
- Over-excitation
What occurs when the Regular and Backup relays actuate?
- Trip and lockout the diesel engine
- Trip and lockout the EDG breaker
- Enable EDG breaker failure protection
What occurs when the EDG test lockout relay actuates?
- Trip and lockout diesel generator breaker
- Enable diesel generator breaker failure protection
(Test Lockout is B/P on an emergency start)
Breaker failure protection
- Trips the diesel
- Trips the normal and alternate feeder breakers.
The following occurs to the EDG when a LOCA occurs:
(Not the sequencer)
- All NORMAL Stops disabled (Emergency stops still work)
- Test Lockout Relay disabled
- Governor shifts to Isochronous (60Hz) and speed control is disabled (10C651)
- Voltage Regulator shifts to Isochronous (4160V) and voltage control is disabled (10C651)
- Opens EDG output breaker if running in TEST
Local Engine Control Switch positions & functions.
- 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.
How do you enable the remote Generator EMERGENCY TAKEOVER and what automatic action is taken away?
- 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 type of valve controls EDG LO Makeup operation, and how can you operate this valve in the case of a loss of power?
LO Makeup to the sump is controlled by a solenoid valve that fails close on a loss of power. It can be overridden locally with a control knob at the base of the valve.
EDG S/U Sequence:
0 RPM
- Cranking cycle timer initiate
- SACS cooling water valve opens
- Low Air start pressure alarms lockout