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
