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EDGs
N/A
64
Other
Professional
05/29/2015

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Cards

Term
What signals auto start the EDG and where are these signals generated from?
Definition

Level 1 and Hi DW pressure come from core spray logic.

One division of logic is enough to start all 4 EDGs.

Under voltage will also start the EDGs.

The signals come from the ESF and EDG 4160V busses.

480V busses have UV schemes but do not start the EDGs.

Term
Which signals determine that the EDG is operating in the ‘Emergency Mode’?
Definition
LOCA Signal (L1 or High DW Pressure from CS Logic).
Term
Why do the 6 and 9 breaker positions input into EDG “Emergency Mode” the circuit?
Definition
The Undervoltage/Load Shed string will reset when the bus is reenergized by the EDG so in order to keep the EDG in the emergency mode these are inputs to the start cicuit.
Term
What does the Emergency Signal Bypass Switch do? Why is it needed and when would it be used?
Definition
Only bypasses the the LOCA signal. If DW pressure was higher that the setpoint and we wanted to shut off the EDGs.
Term
Describe the indications in the Control Room for a 4160V ESF bus lockout.
Definition
All source breakers open 6, 8 , and 9 breakers tripped.
Term
During an ESF bus lockout, how does the EDG respond? Explain.
Definition
The EDG would not start since the bus lockout relay is interlocked in the EDG start circuit so the EDG does not start during a ESF bus lockout.
Term
What is the status (TS wise) of the EDG when operating in parallel with offsite power? Why?
Definition
The EDG is INOPERABLE. Underfrequency relay is not tech spec
Term
How would the EDG respond to a loss of offsite power when operating in parallel with offsite power?
Definition
The EDG would remain tied to the buss initially. As the EDG tried to pick up load the under frequency relay (which is enabled with the 3 and 6 breakers closed) would open the EDG output breaker. This would unbypass the UV relays and allow normal load shedding to occur.
Term
What signals enable/initiate EDG load sequencing?
Definition
EDG emergency start signals enable the load sequencer and the EGD output breaker closing initiates the sequencer.
Term
Which ESF 480V bus undervoltage scheme is different from the rest and why?
Definition
The 72C bus UV relays remain active even though the EDG 12 output breaker is closed. This is to ensure the an UV trip on the 72C bus will initiate a transfer of 72CF. Otherwise 72CF would be inoperable every time EDG 12 is tested.
Term
What does the EDG Diff trip measure?
Definition
Current within the generator phases as compared to current after the output breaker.
Term
Which alarms are non-essential trips?
Definition
Generator field
Generator ground
Generator over voltage
<4 inches Jacket level
>195 deg jacket temp
<8 psi jacket pressure
<7psi fuel oil pressure
>225 deg lube oil temperature
Term
Why does the Generator Trouble alarm come in on every EDG automatic load sequence?
Definition
This alarm is brought in by Field failure or Generator Bearing high temp. On each EDG start the power to the Generator Bearing temp monitor is lost for a short time during sequencing. This brings in the alarm. When power is restored the alarm must be acknowledged locally to clear the control room alarm.
Term
What causes the EDG not ready for auto start alarm?
Definition
Mode Control Switch in - Maint Pull Out
Term
During EDG surveillances, at what times will the EDG not perform its function automatically and will require operator action to restore?
Definition
Mode Control Switch in - Maint Pull Out
Term
What causes the EDG not in auto alarm?
Definition
Any Aux equipment disconnect switch out of position.
Term
The EDGs start automatically upon receipt of LOCA and/or LOOP signal and reach rated speed and voltage within _______________
Definition
10 seconds
Term
diesel HP, RPM, Voltage
Definition
3,967HP at 900 rpm, driving a 4160VAC,
Term
Normal feed breaker is the "no. ______" breaker. Power is fed to the EDG bus via the "no.________" breaker.
Definition
normal 6 EDG 8
Term
Construction of EDG
Definition
- 12 cylinder, opposed piston, dual crankshaft connected by a vertical drive (bevel gear). The crankshafts rotate in opposite directions. The lower crankshaft leads the upper by 18o. The lower crankshaft delivers power to the generator through the crankshaft coupling. A timing chain drives 2 camshafts from the upper crankshaft. The camshafts determine the timing of fuel injection
Term
EDG KW ratings
Definition
Continuous: 2,850kW • 2,000 hr: 3,100kW • 300 hr: 3,250kW 30 min 3,500KW
Term
EDG Tech Spec Frequency
Definition
58.8 -61.2 HZ
Term
EDG Tech Spec Volts
Definition
3850-4580 Volts
Term
Speed that EDG flashes field
Definition
250 RPM
Term
Tech Spec Fuel oil storage tank 7 day
Definition
35280 gal
Term
Tech Spec Fuel oil storage tank 6 day
Definition
30240 gal
Term
Fuel oil storage tank capacity
Definition
42000 gal
Term
Day tank tech spec
Definition
1 hr of fuel (210 gal)
Term
Day tank capacity
Definition
550 gal
Term
EDG fuel path
Definition
Storage tank transfer pump day tank (overflow) Engine driven pump(standby pump) duplex filter fuel injectors(overflow line)
Term
EDG standby oil pump auto start
Definition
EDG standby pump starts at 10# lowering and RPM >250
Term
DGSW pump serves which systems
Definition

Jacket coolant

Lube oil

Air coolant

Term
How is DGSW normal flow rate set
Definition
throttle valve at inlet of cooler
Term
DGSW redundancy
Definition

1 cross-tie per division. Can x-tie diesels in the same division.

1 Div of DGSW can only cool 1 EDG at a time!

Term
DGSW standby pump Auto start
Definition
>250 rpm 14 sec time delay
Term
DGSW Flow path
Definition
RHR reservoir DGSW pump Air coolant Lube oil Jacket coolant Cooling towers
Term
EDG jacket cooler high temp alarm
Definition
195F
Term
EDG jacket cooler low press
Definition
8 psig
Term
EDG jacket coolant expansion tank level trip
Definition
4 inches
Term
EDG Low lube oil press trip
Definition
23#
Term
EDG lube oil high trip
Definition
225F
Term
Lube Oil sump level low
Definition
150 GAl
Term
Lube Oil temp low?
Definition
105F
Term
When is Pre-lube done
Definition
For 2 minutes prior to manual start.
Term
How is prelube provided during autostart?
Definition
Lube Oil Air Boosters
Term
Lube Oil tank level Hi/low?
Definition
270/62 gal
Term
Purpose of air start system.
Definition
Air to start EDG For the Air Coolant TCV (F023A-D). For the main bearing oil boosters. For the governor actuator booster (on EDG start).
Term
TS low limit (5)
Definition
215#
Term
EDG air Press Low Alarm
Definition
220#
Term
EDG air Compressor Start
Definition
225#
Term
EDG air Compressor Stop
Definition
250#
Term
EDG Non-essential Trips
Definition
Generator Field Failure - contact closes on loss of generator field. A manual exciter trip could cause this. Generator Overvoltage closes on overvoltage. Generator Ground Fault - active only when the generator is paralleled. Fuel Oil Pressure Low Jacket Coolant Level Low Jacket Coolant Pressure Low Jacket Coolant Temperature High Oil Temperature High
Term
EDG Essential Trips
Definition

CLOGS

Crankcase Pressure High (0.5”water)

Lube Oil Pressure Low (23 psig)

Overspeed (1035 to 1053 rpm)

Generator Differential

Start Failure (within 7 seconds reach either 250 rpm, 810 rpm or sufficient jacket coolant supply pressure).

Term
EDG Crankcase Pressure High
Definition
(0.5”water)
Term
EDG Lube Oil Pressure Low
Definition
(23 psig)
Term
EDG Overspeed
Definition
(1035 to 1053 rpm)
Term
EDG Start Failure
Definition
(within 7 seconds reach either 250 rpm, 810 rpm or sufficient jacket coolant supply pressure).
Term
How does the EDG respond if, following the LOCA, a Loss of Offsite Power (LOP), subsequently occurs?
Definition
The EDGs start automatically upon receipt of LOCA and/or LOP signal and reach rated speed and voltage within 10 seconds. However, the EDGs breakers will not automatically close to the plants electrical bus network unless either a LOP and/or loss of EDG bus voltage occurs. If a LOP and/or loss of EDG bus voltage occur an automatic sequencer will load the EDGs in an orderly manner to avoid overloading and damaging the equipment. Only the loads necessary for safe shutdown are automatically loaded to the EDG.
Term

Draw

Fuel Oil and Storage

 

Definition
[image]
Term

Draw

EDG jacket cooling system

Definition
[image]
Term
Draw EDG air cooler coolant
Definition
[image]
Term

DRAW

EDG LUBE OIL SYSTEM

 

Definition
[image]
Term

 

EDG AIR INTAKE AND EXHAUST SYSTEM

 

Definition
[image]
Term

 

EDG AIR INTAKE AND EXHAUST SYSTEM

 

Definition
[image]
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