Galvanic Corrosion Overview

A yacht or commercial vessel is an important asset worthy of the best corrosion and safety grounding protection available. While protective coatings and anodes can help protect your boat, a more reliable method is required to deal with the galvanic corrosion circuit created by the shore power connection. 

The Galvanic Corrosion Problem:

Whenever a boat is connected to shore power, the hull and drive system are connected to the shore grounding system and to other adjacent vessels (also connected to shore power) via the grounding conductor in the shore power cable. This connection, while required for safety, creates a galvanic corrosion cell involving the dissimilar metals between boats and between a boat and the shore grounding system.

Boat Diagram

  1. Anode – a metal surface which gives up metal ions (corrodes)
  2. Electrolyte – a medium which conducts ionic current between the anode and cathode
  3. Cathode – a metal surface that picks up metal ions
  4. Metallic Bond – a continuous metallic path that allows current to flow from cathode to anode

The Solution:

A simple method which virtually eliminates this galvanic corrosion problem is to insert an appropriately rated and certified Galvanic Isolator in series with the grounding conductor of the ship-to-shore power cable. The function of the Galvanic Isolator is to provide AC continuity of the grounding conductor (required for safety in the event of an AC fault) and to block the flow of corrosion-causing galvanic current.



Product Selection:
The DEI Galvanic Isolators are the most highly rated products available on the market. DEI Isolators are typically applied using an industry standard method of matching the device to the steady-state current rating of the shore power service. DEI Isolators are offered in 30A, 50/60A, 100A and 200A ratings.  Learn more about product selection.