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

A portable phase sequence indicator is crucial when connecting to an external power source, such as shore power. Ensuring correct phase sequence prevents damage to equipment like motors and ensures proper operation of three-phase systems, aligning with 46 CFR Subchapter J requirements.