Correct grounding and bonding

[boatpoker]

I think a great deal of the confusion in these areas is caused by the improper use of the terminology. The terms "bonded", "grounded", "grounding", "grounding conductor" and electrolysis are sprinkled liberally any time this topic comes up. For example ...
"Electrolysis" - The chemical change in an electrolyte due to the passage of electric current. Using this term to refer to electrolytic corrosion causes one to lose credibility.

[boatpoker]

Originally Posted by goboatingnow

Whole boat RCD or RCDBO, and a good mains ground back to shore is as good as you can make it. Bonding DC negative to AC earth in that case adds little , and can cause more problems then its worth. Furthermore I suggest you never plug into any shore outlet that isnt in itself protected by a RCD ( GFI)

Dave

I agree but if you practice what you preach, I think there may be about four such protected marinas in North America

Unless it is a little mom & pop place with 15amp service

[bazzer]

Originally Posted by boatpoker

I think you mean a "reference electrode". A diode won't tell you anything in this application.

Indeed I mean reference electrode, my mistake and thanks for pointing it out.

[Richard_W]

Originally Posted by boatpoker

I agree but if you practice what you preach, I think there may be about four such protected marinas in North America

Unless it is a little mom & pop place with 15amp service

This is an interesting observation ... no doubting, just surprised at the widespread of the problem. On the other hand, when I bought my property, the floating dock was the ignorance galore ... but it was done by an ignorant homeowner not a professional marina. Need to pay more attention I guess.

[bazzer]

Originally Posted by fstbttms

Because I work in the water and I'd like to talk to the diver in question. I probably know him. Further, this is information all local hull cleaners need to be made aware of.

I doubt if you know the diver in question since this incident took place in San Diego and I believe you are in San Francisco

[bazzer]

Surely, if the AC ground (Earth) and the DC Ground (Earth) are connected then a short between AC Live and DC Live would potentially cause major failures in the DC system, one result could be overheating and fire..
Of course all shore power connections should be GFI protected and I'm surprised to learn it is not in the marina codes here in the USA

[goboatingnow]

Originally Posted by boatpoker

I agree but if you practice what you preach, I think there may be about four such protected marinas in North America

Unless it is a little mom & pop place with 15amp service

well , thats what you get away with using 110Vac, 220-240Vac and you-all be dead guys. ( which is why were covered in RCDs)


AT the very least they all should be retrofitted to US boats given that ABYC has suddenly "discovered" them.

dave

[fstbttms]

Originally Posted by FlyingCloud1937

As a diver I'm suprised you don't take you're own precautions. A simple $200.00 tool that you use before you ever hit the water could and would save your life.

Please do not presume to know what precautions I do or do not take.

Originally Posted by FlyingCloud1937

Every Pro-Diver I know won't go in the water with out one.

Know a lot of "Pro-Divers" do you?

Electric shock drownings (ESD) are extremely rare in saltwater. So rare that none have occured to hull cleaners in the Bay Area in the 18+ years I have been in the business. And we are talking about over 1,000,000 in-water hull cleaning events performed by divers in marinas here during that time. So I think it's safe to assume that swimming in salt water marinas is not inherently dangerous. Which is why it's kinda important that the OP divulge the marina where this incident ocurred. He lists his location as Benicia, which is brackish, so maybe it wouldn't be particularly strange if it happened there. In addition, there aren't a lot of divers working there. But if it happened in a truly saltwater marina, it is a matter of public safety and I'm a little befuddled why bazzer is reluctant to tell us where it occurred.

[bazzer]

Originally Posted by goboatingnow

well , thats what you get away with using 110Vac, 220-240Vac and you-all be dead guys. ( which is why were covered in RCDs)

AT the very least they all should be retrofitted to US boats given that ABYC has suddenly "discovered" them.

dave

What's RCD?

[fstbttms]

Originally Posted by bazzer

I doubt if you know the diver in question since this incident took place in San Diego and I believe you are in San Francisco

In actuality, I probably do know the diver, or at the very least, his boss. If you feel the need to keep the details of this potentially life-threatening situation secret for some reason, no matter, that's on your head. I'll send out some feelers to my San Diego hull cleaning contacts and report back here if I get any response.

[bazzer]

Originally Posted by fstbttms

Please do not presume to know what precautions I do or do not take.

Know a lot of "Pro-Divers" do you?

Electric shock drownings (ESD) are extremely rare in saltwater. So rare that none have occured to hull cleaners in the Bay Area in the 18+ years I have been in the business. And we are talking about over 1,000,000 in-water hull cleaning events performed by divers in marinas here. So swimming in salt water marinas is not inherently dangerous. Which is why it's kinda important that the OP divulge the marina where this incident ocurred. He lists his location as Benicia, which is brackish, so maybe it wouldn't be particularly strange if it happened there. In addition, there aren't a lot of divers working there. But if it happened in a truly saltwater marina, it is a matter of public safety and I'm a little befuddled why bazzer is reluctant to tell us where it occurred.

I am not currently in Benicia. How to you know there have been 1,000,000 hull cleanings done? And I have seen plenty of divers cleaning at that marina which is known by the boaters there to be " Hot". What is a pro diver? Anyone who is willing to get paid to clean from what I have seen. I digress, but in Grand Marina I saw two divers breathing off a Hooka setup which was no more than a air brush compressor. Pro? I think not

Power in Marina's can range from 110 volts AC to 440 volts three phase which freshwater or not can be lethal

[goboatingnow]

Power in Marina's can range from 110 volts AC to 440 volts three phase which freshwater or not can be lethal

Water is lethal, I dont see the ocean being covered up.

Dave

[fstbttms]

Originally Posted by bazzer

How to you know there have been 1,000,000 hull cleanings done?

Because hull cleaning is the business I am in and I have done the math.

Originally Posted by bazzer

And I have seen plenty of divers cleaning at that marina which is known by the boaters there to be " Hot".

Every single marina I have ever worked in has been called "hot" by somebody at one time or another. I hear it all the time. Not only are the marinas not "hot" (a term used primarily by boaters who do not understand why they are going through zincs rapidly) but even if they were, the term does not describe a situation where somebody is going to be zapped by coming in contact with the water.

Originally Posted by bazzer

...in Grand Marina I saw two divers breathing off a Hooka setup which was no more than a air brush compressor. Pro? I think not

This is a statement made in ignorance. You have no idea what constitutes a safe and reliable hookah rig and in fact, every commercially available recreational-level hookah is based on an air compresser (whether it is 12v, 110v or gas-powered) that was designed for another purpose. Many hull cleaners using hookahs (myself included) build their own rigs and they are essentially identical to commecially available units.

[goboatingnow]

Originally Posted by bazzer

What's RCD?

Residual Current Device , or also called a RCB ( residual current breaker) often called a GFI in the US

see Residual-current device - Wikipedia, the free encyclopedia

[Richard_W]

Originally Posted by bazzer

Of course all shore power connections should be GFI protected and I'm surprised to learn it is not in the marina codes here in the USA

It is in the building codes that apply to kitchen, bathrooms, hot tubs, docks, and anything close to water, and connected to main power source. It is just ignorance and stupidity, and not a lack of codes.