I have been installing quite a few Isolation Transformers recently. The reason of course is the new ELCI standard for all new dock pedestal breakers. So if the docks electrical power needs to be updated or replaced it gets the new breakers.
The ELCI (electric leak current interrupter) is just that, any current that goes out on the black wire into your boat, and does not return on the white wire to the shore, is considered to be leaking through the water. The actual threshold is 30 Milli amps but for a boat that might as well be zero leak allowed. And even current returning on the green wire, so not through the water, is still counted as a leak. But it is a good thing, no one wants stray AC current in the water, or to put anyone in danger, so let’s meet the new standard.
There are only two options to meet the new standard, fix the boat’s electrical system so there are on ground/neutral connections onboard, or isolate the boat’s electrical system from the shore with an isolation transformer.
Depending on how old the boat is, fixing the electrical system which is otherwise working fine, may not be a good option. The first step is to evaluate what it would cost to fix, or rewire, and if that needs to be done any way for other safety and comfort reasons. If not then an isolation transformer will stop any AC current from leaving the boat. It also has the added benefit of being the ultimate protection against damaging DC current from other boats in the marina.
