EDGs Flashcards
What are the EDG Auto Starts?
- Load Shed (Loads to Bus)
- SI (does not load to bus)
- LOOP
If an EDG auto starts on a Load Shed, does it load to the TBUS?
Yes, it loads to the TBUS
If an EDG auto starts on a SI without a load shed, does it load to the TBUS?
No it does not auto load to the TBUS
What are the EDG Auto Trips (With DC Power)?
- Bearing Temp High (195°F or 175@10°F/min
- Incomplete Start
- Gen Phase Overcurrent
- CO2 Actuation
- Fuel Oil Press Low* (10 psig)
- Lube Oil Press Low * (25 psig)
- Air Chest Press high (25 psig)
- Neutral Overcurrent
- Gen Phase Differential
- Electronic Overspeed (110% 565 rpm)
What are the EDG Trips available Without DC Power?
- Mechanical Overspeed
- Worthington/Manual Fuel Valve (MFV)
What are the only EDG TRIPS available after the EDG Auto Starts on an SI, LOOP or Load Shed?
(With 250 VDC Available)
- Gen Phase Differential
- Electronic Overspeed (110%)
- Manual Push Button
(Control Switch HELD in Stop)
The starting Air Receivers are sized to do how many EDG starts?
Each tank has enough air to start the EDG 2 times and still have 100# for control air
What are the EDG Starts?
- CR Control Switch
- Local Push Button
- Load Shed (loads to bus)*
- SI (does not load to bus)*
- Worthington/Manual Starting Air Valve (MSAV/Worthington) (allows start during loss of 250VDC control power)*
How do the starting air valves fail on a loss of 100# ctrl air?
- Fail as is
What happens on a loss of the electronic governor?
- EDG will speed up until Mechanical Governor takes over
* * Mechanical governor is the back up to Electronic governor, set point for mechanical governor is 61 Hz (523 RPM)
Where does the field flash come from on a fast speed start?
- Field flash comes from 1kV inverter
Where does the field flash come from on a slow speed start?
- Field flash comes from residual magnetism
At what percentage of rated speed does the field flash stop on a fast speed start?
- 80% speed stops field flash during fast speed start
What are the 1KV inverter Loads?
- Field Flash (Fast Start) (Slow Start if button is pushed)
- Bearing Temp Monitor
- Speed Transmitters
- Local/Remote Control Transfer Relays
How long does the Throttle Control Cylinder (TCC) extend for on a EDG Trip and why?
TCC will extend for 2 minutes on trip to prevent re-start of EDG
Will a EDG start with a loss of 100# Ctrl Air?
No, because if 100 # (control air) system is lost, TCC extends on loss of air
How can a load shed signal be disabled?
-When the EDG output breaker control switch is in close or lockout
How fast does the EDG start on a start signal?
- Reach’s rated speed within 10 seconds of start signal (Fast Start)
- 3500 kW
- 514 RPM
When do run relays energize to allow power to bus?
- Run relays energize at 95% running speed. At this point they start auxiliary equipment, input to Load Conservation, and provide necessary interlocks and permissives
What is disabled on a Slow Speed Start?
- Jet Assist
- Field Flash
If an emergency start signal initiates at any time during the slow start, what will happen?
- The slow start circuit automatically drops out and an emergency start takes place (Fast Speed)
How is Generator excitation/field flash failure affected on a loss of ctrl pwr while the diesel is running?
- No impact
How is Generator excitation/field flash failure affected on a loss of ctrl pwr while the diesel is not running?
- Results in the inoperability of the EDG
Why do we have slow speed start circuitry?
- Its easier on the EDG
Are the EDG trip relays energize or de-energize to trip?
- Energize to Trip
Are the EDG start relays energize or de-energize to run?
- De-Energize to run
1/bus – want to run if lost power
Is the EDG considered Inop during a surveillance?
- EDG is INOP during testing because the Load Shed signal is deactivated
When the TCC extends, what is it doing?
- Forces the fuel racks closed
What does TS 3.8.3 State?
- Maintain 46,000gal of fuel oil
What does TS SR 3.8.1.6 have you verify?
- That each air receiver is ≥ 190#
What will happen on a loss of ctrl air to the TCC?
- It extends
What does TS 3.8.1 Require?
- 2 EDGs operable M 1-4 & opposite 1 EDG from opposite unit to support ESW
How is ctrl air designed to fail on a loss of 250V DC?
- Valves will fail in a position such that a control air pathway will be available to the TCC
What is the auto trip with a loss of 250V DC?
- Mechanical Overspeed
What supplies power to the EDG 1Kv inverter
- 250V DC Battery Charger/Battery
Will a loss of 250v DC cause the EDG to be in operable?
- Yes, A loss of power will render the EDG inoperable, it can not auto start and load.
If you lose normal power to the HVAC supply or exhaust fan, what does it swap to?
- The EDG will power it
IF the EDG output Bkr is in closed or Lockout position, what does it defeat?
- Defeats Load Shed
What loads sequence on during a load shed w/out an SI?
CCW pump
ESW pump
MDAFW pump
NESW pump
What loads sequence on during a load shed w/an SI?
- CCP
- SI pump
- RHR pump
- CCW pump
- ESW pump
- MDAFW pump
- CTS pump (Starts when Phase B active)
- NESW pump (Starts/Then Trips if CTS/ Phase B active)
If you have a load shed without an SI, will your CCP auto restart?
No it won’t, you will have to manually restart it
What does TCC do when the HEA trips?
Extends [Fuel Racks close]
Will loss of Jacket Water cause the EDG to be inop?
Yes
What powers the Normal and Alternate ESW cooling supply valves?
ABD-A and ABD-D (Train Specific)
