250 VDC/Instrumentation Electrical

Question 1

What are the power sources for Unit 1 Control Room Lighting?

Answer 1

• 600V Bus 11A -> Normal Lighting TR 9S (South) -> ABT-1 and -2
• 600V Bus 11C -> Standby Lighting TR 8 -> ABT-1 and -2
• Backup supply from MCAB 250 VDC

Question 2

What is the power source for Unit 1 Turbine Building Lighting (TE1E and TE1W)?

Answer 2

• 600V Bus 11D -> Normal Lighting TR 9N (North)

Question 3

What is the power source for Unit 1 Containment Lighting (CAM)?

Answer 3

• 600V Bus 11D -> Containment Lighting TR 10

Question 4

What is the power source for Unit 1 Aux Building Lighting?

Answer 4

• Normal: 600V 11A -> TR 9S (South) -> AB1E and AB1W
• Standby: 600V 11C -> TR 8 -> 1PSBE and 1PSBW

Question 5

What are the power sources for Unit 2 Control Room Lighting?

Answer 5

• 600V 21D -> Normal Lighting TR 9N (North) -> ABT-1 and -2.
• 600V 21C -> Standby Lighting TR 8 -> ABT-1 and -2.
• Backup supply from MCAB 250 VDC.

Question 6

What is the power source for Unit 2 Turbine Building Lighting (TE2E and TE2W)?

Answer 6

600V 21A -> Normal Lighting TR 9S (South)

Question 7

What is the power source for Unit 2 Containment Lighting (CAM)?

Answer 7

600V 21D -> Containment Lighting TR 10

Question 8

What is the power source for Unit 2 Aux Building Lighting?

Answer 8

• Normal: 600V 21D -> TR 9N (North) -> AB2E and AB2W
• Standby: 600V 21C -> Standby Lighting TR 8 -> 2PSBE and 2PSBW

Question 9

What is the concern for power sources for Unit 2 lighting?

Answer 9

If Train A (21C and 21D) are lost:
- Power is lost to all three Control Room Power (CRP) Panels
- Both AC sources for CR Lighting are lost

Question 10

What is the power source for CRID 1?

Answer 10

• Primary: MCCD 250 VDC
• Alternate: EZC-C (600V 11/21C)

Question 11

What is the power source for CRID 2?

Answer 11

• Primary: MCCD 250 VDC
• Alternate: EZC-D (600V 11/21D)

Question 12

What is the power source for CRID 3?

Answer 12

• Primary: MCAB 250 VDC
• Alternate: EZC-A (600V 11/21A)

Question 13

What is the power source for CRID 4?

Answer 13

• Primary: MCAB 250 VDC
• Alternate: EZC-B (600V 11/21B)

Question 14

What effect does CRID normal power source OOS have on Tech Specs?

Answer 14

• CRID inverter is INOPERABLE
• CRID Bus is OPERABLE

Question 15

What effect does a CRID being powered from CRP-3 have on Tech Specs?

Answer 15

• CRID Bus is INOPERABLE

Question 16

What function does a CRID Inverter “ALT Source to Load” PB do?

Answer 16

Electronically transfers the static switch to the Alternate Source

Question 17

What function does a CRID Inverter “Inverter to Load” PB do?

Answer 17

Transfers the load from the Alternate Source to the Inverter

Question 18

What function does a CRID Inverter “Manual Output Selecter” Switch do?

Answer 18

Allows the inverter to be bypassed while maintaining a source of power from the Alternate Source.
- Make-before-Break

Question 19

What does the “In Synch” light LIT on a CRID Inverter mean?

Answer 19

Alternate power supply is available.

Question 20

What is the power source for CRP-1 and CRP-2?

Answer 20

• AB1W (AB2W)
  OR
• 1(2) PSBW
  Via ABT-3

Question 21

What is the power source for CRP-3?

Answer 21

• AB1E (AB2E)
  OR
• 1(2) PSBE
  Via ABT-5

Question 22

What is the power source for Unit 1 CCRP?

Answer 22

• MCCD 250 VDC
  OR
• EZC-D (600V 11/21D)

Question 23

What is the power source for Unit 2 CCRP?

Answer 23

• MDAB 250 VDC
  OR
• EZC-A (600V 11/21A)

Question 24

What is the power source for RPI?

Answer 24

• CRP-3
  OR
• ELSC

Question 25

What is the power source for Emergency Lighting?

Answer 25

Receives trickle voltage from local lighting panels to the solid state battery charger.

Question 26

What is the power source for TSC-UPS?

Answer 26

• The three TSC-UPS inverters receive power from either the TSC battery chargers (Normal) or the TSC-UPS battery (Backup)
• The three TSC-UPS inverter static switches and bypass switches can be powered from 600V 11(21)A via an Isolimiter.

Question 27

What is the power source for the TSC-UPS Battery Chargers?

Answer 27

• 600V 11(21)C
  OR
• 600V Security Bus

Question 28

What is the Auto-Retransfer Lockout Sequence?

Answer 28

• If the normal supply is lost, the inverter static transfer switch switches to the alternate supply.
• If the normal supply returns, 30 seconds later the inverter static switch retransfers to the normal supply.
• The Auto-Retransfer Lockout feature is now locked out unit the Auto-Retransfer Reset PB is pressed. (Light is LIT)
• If the PB is not pressed and the normal supply is lost, the inverter static switch will transfer to the alternate supply and NOT retransfer.

Question 29

The 250 VDC Batteries are sized to ensure power for how many hours during a LOOP?

Answer 29

3 hours

Question 30

The 250 VDC Batteries are sized to ensure power for how many hours during a SBO?

Answer 30

4 hours

Question 31

The BOP Battery is sized to ensure power for how many hours during a LOOP?

Answer 31

2 hours

Question 32

How do ground detection lights indicate a ground?

Answer 32

Of the 3 lights, the one that goes out or is much dimmer than the others indicates a ground.

Question 33

Which 250 VDC battery has more capacity and why?

Answer 33

U1 CD (train A) Battery.
- It has additional loads

Question 34

What is the power source for the BOP Battery Chargers?

Answer 34

600V BMC/CMC

Question 35

What is the power source for the CD (Train A) Battery Chargers?

Answer 35

• Charger 1 from 11(21)D via EZC-D
• Charger 2 from 11(21)C via EZC-C

Question 36

What is the power source for the AB (Train B) Battery Chargers?

Answer 36

• Charger 1 from 11(21)A via EZC-A
• Charger 2 from 11(21)B via EZC-B

Question 37

What happens to current draw as a battery is expended?

Answer 37

Rise steadily until the design battery capacity is exhausted.

Question 38

What happens if there is a differential sensed on BMC or CMC Transformer?

Answer 38

• Low side and high side breakers immediately open and the tie-breaker closes
• There is no 30 cycle delay!