What is the purpose of a shore power galvanic isolator?

The purpose of a shore power galvanic isolator is to protect from galvanic corrosion caused by shore power. When a boat is connected to shore power, there is a potential for stray electrical currents to flow through the water, leading to a phenomenon known as galvanic corrosion. This type of corrosion occurs when two dissimilar metals are in contact in a conductive solution, such as seawater, creating a battery effect that can degrade metal components over time, like the hull, propellers, and through-hull fittings.

A galvanic isolator is designed to block these stray currents from flowing between the shore power system and the boat’s electrical system. By providing an effective barrier for direct current (DC) while allowing alternating current (AC) to pass through for the boat’s electrical needs, it helps to prevent corrosion linked to galvanic action and prolong the lifespan of metal components.

In contrast, options referring to enhancing electrical performance of generators, preventing battery drainage, or improving fuel efficiency are unrelated to the function of a galvanic isolator and do not address the specific concerns associated with galvanic corrosion when utilizing shore power.