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

Correct Answer: Option D — preparing to make the shore power connection

Verifying correct phase rotation prior to energizing shipboard loads from a shoreside source prevents catastrophic reverse rotation of multi-phase machinery. Per Title 46 CFR Subchapter J, a portable phase sequence indicator must be used when fixed switchboard meters are inoperative before closing shore power breakers.