DC Power Distribution - .5

Question 1

Float Charge

Answer 1

Charger output ~1VDC above battery voltage.

Question 2

Equalizer Charge

Answer 2

Charger output ~5VDC above battery voltage.

Question 3

How long does it take to fully charge batteries?

Answer 3

12 Hours

Question 4

How can you prevent charger damage?

Answer 4

Always open AC bkr first and close last.

Question 5

DC High Voltage Shutdown

Answer 5

Occurs when charger output is high enough to trip charger.

Question 6

Fused disconnect connections

Answer 6

Battery charger and fuses, or
Test stabs.

Question 7

Ground detection

Answer 7

One light gets brighter, one more dim if ground is present.

Question 8

1E 125VDC Battery operation

Answer 8

1. 4 channels
2. Battery lasts 4 hours
3. Battery trips: 152 VDC and
   Over current- Trips AC supply, DC output, and 480 VAC MCC feeder bkrs.

Question 9

Non-1E 125VDC operation. *

Answer 9

1. Battery lasts 4 hours
2. Chargers trip on high voltage at 152VDC
3. Guardhouse has its own diesel (used during LOP)
4. Battery chargers trip on a LOP. Can be overridden to restore.
5. Normally two chargers in service for each switchgear (except guardhouse)
6. LOCA load shed

Question 10

1E 250VDC operation.

Answer 10

Rated for four hours and only used for HPCI and RCIC pumps and valves.

Question 11

Non-1E 250-VDC operation

Answer 11

1. Rated for 1 hour
2. LOCA load shed
3. Supply to emergency LO pumps: 3 RFPT, ESOP, MT EBOP.

Question 12

24 VDC panel ID

Answer 12

AD307 & BD307

Question 13

24VDC operation

Answer 13

1. Rated for 4 hours