Coast Guard Exams
Question 67Electricity/Electronics - QMED70% to pass

Under what circumstance would a hand-held portable phase sequence indicator be used should the main switchboard mounted fixed phase sequence indicator be inoperative?

AI Explanation
The correct answer is D) preparing to make the shore power connection. The reasoning is that a hand-held portable phase sequence indicator would be used to verify the phase sequence of the shore power connection before connecting it to the vessel's electrical system. This is a critical safety check to ensure the phases are matched correctly, preventing potential damage to the vessel's electrical components. The other options (A, B, C) do not directly relate to verifying the phase sequence for a shore power connection, which is the primary purpose of using a portable phase sequence indicator in this scenario.