🔍 Key Concepts

• Trace the power path for N (Normal & Final Emergency Power Source) and TE (Temporary Emergency Power Source) from the legend to the one‑line diagram. • Distinguish between temporary emergency vital loads and final emergency loads shown along the bottom of the diagram. • Note how the Automatic Bus Transfer (ABT) switches select between UPS "B" (battery source) and the normal/final emergency bus when power is restored.

💭 Think About

• When normal ship’s power is restored and the emergency switchboard is re‑energized from the main switchboard, which side of each ABT (N or TE) will be supplying the temporary emergency vital loads? • According to the legend, which device actually contains the battery supplying DC power, and how is that battery power routed to the temporary emergency vital loads? • Look at the feeders going to the final emergency loads (450 VAC, 120 VAC, 24 VDC). From which bus or source do these loads get power once normal ship’s power is available again?

✅ Before You Answer

• Verify which conductor labeled N ties back to the emergency switchboard fed from the main switchboard when normal power is available. • Verify which conductor labeled TE ties back to UPS "B" (with batteries) as the temporary emergency source. • Confirm that the statement you choose correctly assigns final emergency loads vs temporary emergency vital loads to either the main switchboard path or the battery/UPS path on restoration of normal power.