Question 132Electricity & Electronics - Assistant Engineer

The correct answer is B) connecting shore power lines to the ship. An electrical phase sequence indicator is useful when connecting shore power lines to a ship, as it ensures the correct phase sequence is maintained. This is important because if the phase sequence is reversed, it can cause damage to the ship's electrical system. Connecting the shore power with the wrong phase sequence could potentially lead to overheating, motor rotation in the wrong direction, and other electrical issues. The other answer choices are not as relevant for the use of a phase sequence indicator. Preparing to parallel alternators, connecting lighting branch circuits, and troubleshooting DC motors do not directly require checking the phase sequence, making options A, C, and D incorrect.