Where should the galvanic isolator components be electrically isolated from?

The correct answer, which identifies the need for galvanic isolator components to be electrically isolated from the external housing, is grounded in understanding the purpose of galvanic isolators themselves.

Galvanic isolators are designed to prevent stray currents from causing galvanic corrosion in metal parts of boats that are immersed in water, largely by breaking the electrical path between the AC power system and the shore power system. When the components of a galvanic isolator are isolated from the external housing, it ensures that there is no unintended current flow through the housing, which could lead to unsafe conditions and potential corrosion of the vessel’s metal components.

By isolating the galvanic isolator from the external housing, you reduce the risk of creating a ground loop, which can lead to various electrical issues, including corrosion and electrical fires. Proper installation and isolation contribute significantly to the longevity and safety of the vessel's electrical system.

Other components such as the AC panel, power supply, or grounding system are integral parts of the boat's electrical system and should maintain connectivity for safe operation. Hence, isolating the galvanic isolator from the external housing is crucial for ensuring that the system functions effectively without adverse side effects affecting the vessel.