Q49 — 125 VDC Battery Charger Transfer
063 G2.1.30 (4.4)
Given:
• Unit 2 is at 100% Power.
• The 2A1 125 VDC Battery Charger is being transferred to the standby charger in accordance with S2.OP-SO.125-0001, 2A 125VDC Battery Charger Operation.
Which ONE of the following completes both statements?
1. The 2A1 and 2A2 125 VDC Battery Chargers are located in the __(1)__.
2. The proper sequence for placing the standby charger in service is to __(2)__.
• Unit 2 is at 100% Power.
• The 2A1 125 VDC Battery Charger is being transferred to the standby charger in accordance with S2.OP-SO.125-0001, 2A 125VDC Battery Charger Operation.
Which ONE of the following completes both statements?
1. The 2A1 and 2A2 125 VDC Battery Chargers are located in the __(1)__.
2. The proper sequence for placing the standby charger in service is to __(2)__.
A. 1) 100 ft. Relay Room
2) remove 2A1 charger from service, then place 2A2 charger in service
2) remove 2A1 charger from service, then place 2A2 charger in service
B. 1) 84 ft. Switchgear Room
2) remove 2A1 charger from service, then place 2A2 charger in service
2) remove 2A1 charger from service, then place 2A2 charger in service
C. 1) 100 ft. Relay Room
2) place 2A2 charger in service, then remove 2A1 charger from service
2) place 2A2 charger in service, then remove 2A1 charger from service
D. 1) 84 ft. Switchgear Room
2) place 2A2 charger in service, then remove 2A1 charger from service
2) place 2A2 charger in service, then remove 2A1 charger from service
▶ Show Answer & Explanation
✓ B. Correct. All the 125 VDC Battery Chargers are located in the 84 ft. Switchgear Room. IAW S2.OP-SO.125-0001, Precaution and Limitation, 3.2, Do NOT operate the 2A1 and 2A2 Battery Chargers in parallel in Modes 1-4. This is to prevent cross connecting the 230 VAC Vital buses. Therefore, the procedure removes the inservice battery charger first, then places the standby charger in service.
✗ A. First part is incorrect. All the 125 VDC Battery Chargers are located in the 84 ft. Switchgear Room. Credible distractor since the A and B 125 VDC batteries are located in the 100 ft. Relay Room. Second part is correct.
✗ C. First part is incorrect. All the 125 VDC Battery Chargers are located in the 84 ft. Switchgear Room. Credible distractor since the A and B 125 VDC batteries are located in the 100 ft. Relay Room. Second part is incorrect. Paralleling battery chargers is not permitted by procedure. Plausible because the applicant may believe that the battery chargers are paralleled first before removing the inservice charger.
✗ D. First part is correct. Second part is incorrect. Paralleling battery chargers is not permitted by procedure. Plausible because the applicant may believe that the battery chargers are paralleled first before removing the inservice charger.
Ref: NOS05DCELEC-11 | LO: NOS05DCELEC-11, Obj 13 — Given plant conditions, relate the DC Electrical System with the following: Battery charger and battery | Source: New | Cognitive: Fundamental/Memory
Connections
- Related systems: DC Power
- Related exam: 2022 NRC Written Exam