Hints and Tips



How to fit a Galvanic Isolator to a SO 42 DS

Another excellent Trevor Bird step by step guide


I have outlined the installation of a Galvanic Isolator which I installed onto my SO 42DS. But first a cautionary note. Certainly in Australia, one of these can ONLY be legally fitted by a licensed electrician. My son is a licensed electrician and he has given this a clean bill of health.


Now for the installation;


A Galvanic Isolator is to be installed as close as possible to the inlet socket, however in this case the most logical place I think to mount this device is behind the navigation station drop down panel. The reason is it is not exposed to any moisture and it is where the cable from the inlet socket is joined to the wiring loom of the boat so it is a logical place to insert the isolator.


If you remove the plastic cable tray covers you can see where the inlet cable joins the wiring loom of the boat.


This picture shows the factory connection for the earth. I must say i was not impressed with the quality of the soldering. Very poor to be honest.


Simply break this connection and insert the Galvanic Isolator. Solder the connection carefully and use the same gauge wire. I used a couple of layers of heat shrink to make it all look nice.


From now on, when hooked up to shore power, galvanic currents cannot flow through the earth connection because of the forward voltage drop across the diodes in the isolator. This stops you and every other boat at the Marina forming a great big battery caused by dissimilar metals, and therefore stops destructive currents slowly eating away your expensive metal bits. I hope this may help someone who would like to fit one of these isolators. Remember, in Australia at least you must be a licensed electrician.


This article was originally part of the discussion on AC grounding options on the Jeanneau Forum see: AC Earth Grounds