All guides · Shore power and installation
I would have the boat's total shore power installation evaluated before choosing galvanic protection. An isolator and a transformer work differently, and the choice also depends on space, power requirements, and the existing installation.
Why does shore power enter the picture?
The shore power protective conductor can become part of an electrical connection between the boat and the shore facility. This can contribute to galvanic corrosion on underwater metals. At the same time, the protective conductor performs an important safety function and must not be removed as a solution to corrosion.
| Solution | Principle | Considerations |
|---|---|---|
| Galvanic isolator | Blocks low DC voltages in the shore power grounding, while designed to maintain the safety function. | Rated current, documentation, location, and the installation's grounding. |
| Isolation transformer | Transfers AC energy between isolated windings and provides galvanic separation between shore and boat. | Power, weight, space, ventilation, and configuration of protection on the boat side. |
Look at the installation you actually have
Find information about the shore power inlet, residual current device (RCD), fuses, any inverter/charger, and the boat's grounding and bonding connections. If the boat has multiple inlets, they must all be included in the assessment. I would ask a professional with experience in marine installations to draw the connections if documentation is missing.
The transformer's rated power must match the planned consumption. A larger shore power plug does not provide more power through a smaller transformer. Conversely, a large transformer will not necessarily be practical if there is a lack of a dry, ventilated place with appropriate mounting.
Make two quotes comparable
Ask both suppliers to describe which parts of the shore power system the quote includes, what continuous load the solution allows, and how the protection is verified upon delivery. Compare the completed installation rather than just the price of the box.
Corrosion must still be investigated
Rapid anode consumption or new attacks on metal should be investigated. Galvanic isolation is not a general cure for all forms of corrosion, and anodes, material combinations, and any electrical faults must still be assessed.
This guide is a help for choices and questions. The actual modification of the 230 V system, grounding, and protection requires proper design and verification. I would not buy a component before its role in that specific installation is clarified.
Sources and manufacturer documentation
Manufacturer documentation checked September 2026. Always follow the manual for the specific model and installation. The calculation examples are simplified examples for planning purposes.
Moving forward with your solution
Feel free to send a list of components for the shore power system, and I will help clarify which products should be included in the assessment.