Fail-Safe Galvanic Isolator vs. Isolation Transformer

[CharlieJ]

Gator:

Not sure that 30 mA leakage/ground fault on the boat translates to 30 mA in a swimmer's body.

It doesn't, necessarily. I was simply trying to show how little current (>17mA) at 120VAC/60Hz it takes to potentially end life. Of course the Europeans can stand < 50mA at 230VAC/50Hz according to gbn's reference, but then again, they have been at this a lot longer than we Colonials. ;-)

[ebaugh]

I'm a little late to this thread...and nothing new to offer on the "safety" aspects. However I just replaced my GI with an IT. In part, since I'm going to be residing in a marina for the foreseeable future.

But what was not mentioned is the load balancing offered by the IT. I have 3 120V A/C units wired on one side of a 50A 240/120 service connection. With all three units running, that pretty much saturates that side. It came that way, like some other all electric boats since if the galley stove is in full operation, it saturates the other side.

In Honduras, a weak connection on the shore power outlet pretty much welded my plug to the pedestal. While the ships end was just fine. The weak connection is the friction connections on the plug. The IT balances the load, so that with just A/C, I'm pulling 1/2 the current on the shore power cable, with the 24/7 A/C loads. Obviously with the galley going, there is little improvement. But that is usually transient, and overall the loads on the shore power connections are reduced significantly. This doesn't apply much for EU wired boats, or US boats with 240V A/C. But I have seen several 40-50 ft US powerboats wired this way...

It is more expensive, but does not have to be thousands. I found a used transformer for $300, but did someone mention heavy? The motor freight Virginia to Florida was another $200....