🔍 Key Concepts

• Backfeed and paralleling risks between shore power and ship’s generators • Standard procedures for switching from ship’s power to shore power in port or shipyard • Why you avoid having two live power sources on the same bus without strict control

💭 Think About

• Think about what could happen if both the shore power and ship’s generators were connected to the same bus at the same time without proper synchronization. • Which option describes a condition where there is no risk of unintended paralleling or backfeeding between shore power and the ship’s generators? • In normal port or shipyard practice, what is the sequence: do you connect shore power first, then disconnect the ship’s generators, or disconnect the ship’s generators from the bus before closing in shore power?

✅ Before You Answer

• Verify which choices ensure only one live source is connected to the main bus at the moment you close the shore power breaker. • Check whether the option suggests paralleling shore and ship’s generators directly; consider if this is normally allowed or safe for typical shipboard systems. • Eliminate any answers that imply “any time” or “if a special device is used” without addressing the fundamental issue of preventing simultaneous sources on the same bus.