EDG & Auxiliaries (RQ-C-4733)

Question 1

• U1 had an SI
• CD EDG is the only power supply to T11D
• SI is reset
• CD EDG was manually tripped in error

Will the EDG restart automatically?

Answer 1

• No. Since SI was reset the HEA needs to be reset in the Control Room

Question 2

U2 has experienced a SI. The 2AB EDG started but subsequently tripped. Which ONE of the following signals was the cause of the trip

A) Generator Phase Overcurrent
B) Main Bearing Temperature
C) CO2 actuation
D) Engine Speed

Answer 2

D) Engine Speed

Question 3

U1 has experienced a LOOP. The 1AB EDG began a FAST start, but experienced the following: Field amp = 0 Field volts = 0

Which ONE of the following best explains this condition

A) Auto voltage regulator setpoint is too low
B) Inverter field flash failed
C) Manual voltage regulator setpoint is too high
D) Exciter has residual magnetism

Answer 3

B) Inverter field flash failed

Question 4

The 2CD EDG has had one air receiver tagged out and isolated for 12 hours. Two hours ago the 2CD EDG was started to verify operability.

If U2 were to receive an SI signal, what would be the MINIMUM number of STARTS available to the CD EDG

A) 4
B) 3
C) 2
D) 1

Answer 4

C) 2

Question 5

U1 had an SI. The 1AB EDG started and loaded properly. What would happen if the 100# Control Air header to the 1AB EDG suddenly depressurized?

A) Nothing. The Control Air is only necessary for starting the EDG
B) The Throttle Control Cylinder will extend, causing the fuel racks to close
C) The Throttle Control Cylinder will retract, causing the fuel racks to open
D) The intake after-cooler ESW (3 way) valves will fail to the bypass position

Answer 5

B) The Throttle Control Cylinder will extend, causing the fuel racks to close

Question 6

The U1 AB EDG Room exhaust fan was running, but has automatically stopped. Which one of the following conditions would have caused that action?

A) Room temperature cooled to 75 deg F
B) The SI reset button was depressed
C) The CO2 system actuated
D) EDG has been stopped for 25 minutes

Answer 6

C) The CO2 system actuated

Question 7

U1 and U2 were operating at 100% power with their East ESW pumps running and crossties open.

• U2 CD EDG is in a normal standby alignment w/ ESW normal supply open for minimum flow
• High winds caused damage to U2 resulting in a Main Turbine Tirp and loss of the U2 RATs
• Both U2 EDGs started and loaded but T21D failed to energize

Which ONE of the following best described the ESW cooling water status to the U2 CD EDG

A) ESW cooling has been lost
B) U1 E ESW is supplying cooling
C) U2 W ESW is supplying cooling
D) U1 W ESW is supplying cooling

Answer 7

D) U1 W ESW is supplying cooling

Question 8

Describe Load shed setpoint, coincidence, and sequence of events

Answer 8

• 94(93)V
• 2/3 T busses
• 2 sec delay
• Opens breakers and starts EDG

Question 9

Describe DBV setpoint, coincidence, and sequence of events

Answer 9

• 113V
• 2/3 on T11(21)A or T11(21)D
• 9 seconds alarm (+ load shed if SI or Lo-Lo SG present)
• 99 seconds transfer to RAT
• 120 seconds initiates load shed