EDGS

Question 1

What are the EDG Trips available Without DC Power?

Answer 1

• Mechanical Overspeed (112% of 514 RPMs)
• Worthington/Manual Fuel Valve (MFV)

Question 2

What are the only EDG TRIPS available after the EDG Auto Starts on an SI or Load Shed? (With 250 VDC Available)

Answer 2

• Gen Phase Differential
• Electronic Overspeed (110%)
• Manual Push Button

Question 3

What are the EDG Starts?

Answer 3

• CR Control Switch
• Local Push Button
• Load Shed (loads to bus)
• SI (does not load to bus)
• Worthington/Manual Starting Air Valve (allows start during loss of 250VDC control power)

Question 4

How do the starting air valves fail on a loss of 100# ctrl air?

Answer 4

Fail as is

Question 5

What happens on a failure of the electronic governor?

Answer 5

EDG will speed up until Mechanical Governor takes over

set point for mech governor is 60.8-61 hz

Question 6

Where does the field flash come from on a fast speed start?

Answer 6

From the 1kV inverter

Question 7

Where does the field flash come from on a slow speed start?

Answer 7

From residual magnetism

From 1kV loads IF button is used to flash the field

Question 8

What are the 1KV inverter Loads?

Answer 8

• Field Flash (Fast Start) (Slow Start if button is pushed)
• Bearing Temp Monitor (SG-40)
• Speed Transmitters
• Local/Remote Control Transfer Relays

Question 9

How long does the Throttle Control Cylinder (TCC) extend for on a EDG Trip and why?

Answer 9

TCC will extend for 2 minutes on trip to prevent re-start of EDG

Question 10

Will a EDG start with a loss of 100 psi Ctrl Air?

Answer 10

NO!
TCC extends on loss of 100 psi control air

it will trip if running, also

Question 11

What causes Load Shed to be disabled?

Answer 11

EDG output breaker control switch is in close or lockout

Question 12

When do run relays energize to allow power to bus?

Answer 12

At 95% running speed

start aux equip, input to load cons and provide interlocks/permissives

Question 13

If an emergency start signal initiates at any time during the slow start, what will happen?

Answer 13

The slow start circuit automatically drops out and an emergency start takes place (Fast Speed)

Question 14

Are the EDG trip relays energize or de-energize to trip?

Answer 14

Energize to Trip

Question 15

Are the EDG start relays energize or de-energize to run?

Answer 15

De-Energize to run
(1 per bus – want to run if lost power)

Question 16

Why is the EDG considered Inop during a surveillance?

Answer 16

Because the Load Shed signal is deactivated

Question 17

How is ctrl air designed to fail on a loss of 250V DC?

Answer 17

so that control air will be available to the TCC

Question 18

What is the auto trip available with a loss of 250V DC?

Answer 18

Mechanical Overspeed

(112% of 514 rpms)

Question 19

What supplies power to the EDG 1Kv inverter

Answer 19

250v DC Charger/Battery (Train Specific)

Question 20

What loads sequence on during a load shed WITH a SI?

Answer 20

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)

Question 21

Will the loss of HVAC make the EDG INOPERABLE?

Answer 21

YES

Question 22

What ventilation is required by TS LCO 3.8.1 for an EDG to be OPERABLE?

Answer 22

Supply Fan, Exhaust Fan and Cabinet Fan

Question 23

When is the field flash disabled during a fast speed start?

Answer 23

80% Speed

Question 24

What happens to an EDG in standby if a CO2 discharge occurs in the EDG CD room?

Answer 24

The CO2 actuation signal trips the 87X relay. It must be reset or the EDG will not start when needed