ELCI with Isolation Transformer and Inverter/Charger

[nofacey]

Jedi is 200% right…..avoid the unnecessary ELCI (KISS), and ground via the isolation transformer (that’s why you buy them!)

[goboatingnow]

Originally Posted by Bertinc

I cannot emphasize the importance of attending an ABYC or comparable Marine Corrosion course. And ask questions, lots of questions until you get the right answers.
Don't accept past practices by boat builders or hear say. Get accurate information then you can exercise your free will to do what you want on your boat.

Or by preference follow the far better researched ISO standards on the subject. Such standards having the force of law in many jurisdictions unlike an industry led body like the ABYC.

[goboatingnow]

Originally Posted by Bertinc

True, an electrical FAULT current is trying to get back to its source through any and all paths. You want that path to be a low impedance/low resistance path hopefully through a properly sized non-corroded copper/ tinned copper grounding conductor.
The purpose of bonding underwater metals is to keep all conductive metals at the same zero voltage potential. Without a voltage potential no current will flow, and in this case no unwanted current. It can be argued that bonding underwater metals creates unwanted paths for galvanic corrosion but a more important argument would be that not bonding them might result in catastrophic electrolytic flow leading to severe corrosion or a shock leading to muscular paralysis or death in the event of an electrical fault.
The goal is safe use of electricity especially 120 volt AC or higher

Bonding is not desirable on commonplace on grp yachts. The anodes directly fitted to large underwater structures like my sail drive and iron keel protect those. There is no advantage on bonding DNZ or bronze fittings and in fact it offers a path for impressed corrosion. Such bonding is not at all common on European yachts as the ISO requirements do not mandate it for the reasons given.

[goboatingnow]

Originally Posted by Bertinc

True, an electrical FAULT current is trying to get back to its source through any and all paths. You want that path to be a low impedance/low resistance path hopefully through a properly sized non-corroded copper/ tinned copper grounding conductor.

Electricity does not return by “ any and all” paths merely by paths that are electrically connected at both ends. In the case of a properly installed isolation transformer, the only return path is through the “neutral “ wire connecting the supply terminal and the consuming equipment. No other path is possible.

Earth reference supply is problematic on boats as sometimes we have a conductive path via seawater. An isolation transformer should remove that vulnerability

[Bertinc]

I did not say electricity returns... What I said is that fault current returns to its source by any and all means. Electrical safety says to direct fault current on the grounding conductor and not let your body become part of that shocking return path or underwater metals.
An isolation transformer solves the problem or crossed polarity but do to the fact that a motor is bonded and that bond is tied to the equipment ground gives way to different problems.
I guess on underwater bonding of fittings, the only thing we agree on is that we disagree. Let the better lawyer fight it out in the court of law but I would still bond underwater thru-fittings and routinely check the connections along with the GI, ELCI and GFCIs for proper operation.
Water and electricity don't mix and our electrical systems work in a hostile environment.
Enough said on this subject because I'm acutely aware people have varied and quite animate views.

[s/v Jedi]

Originally Posted by Bertinc

I did not say electricity returns... What I said is that fault current returns to its source by any and all means. Electrical safety says to direct fault current on the grounding conductor and not let your body become part of that shocking return path or underwater metals.
An isolation transformer solves the problem or crossed polarity but do to the fact that a motor is bonded and that bond is tied to the equipment ground gives way to different problems.
I guess on underwater bonding of fittings, the only thing we agree on is that we disagree. Let the better lawyer fight it out in the court of law but I would still bond underwater thru-fittings and routinely check the connections along with the GI, ELCI and GFCIs for proper operation.
Water and electricity don't mix and our electrical systems work in a hostile environment.
Enough said on this subject because I'm acutely aware people have varied and quite animate views.

You are wrong. Explain how ground is a return path to the source if that source is a secondary winding of an isolation transformer? Explain how a clean room is safe or an operating room? How a double isolated appliance does not have grounding yet is fully approved?