Little girl gets electrocuted .

[Buck Parrish]

Little girl gets electruted while swimming near marina. She and a couple freinds we're swimming near a boat that was plugged in. Evidently the hull became energized.
They all felt the electricity in their bodies. But the one girl was unable to controll her mucsles and she died in the water. She wasn't even touching the boat.

A rescuer tried to save her. But he to was over welmed by the electricity and had to get out of the water.

Does the electricity go through water or is it in the minerals, or dirt (muddy) in the water?

I've heard of this in a bath tub where their is metal near by. But never in a lake.

I'll try to post the article.
Mean while if you are wireing any marina's . Make sure the ground is good and solid.

 

[zbang]

Does the electricity go through water or is it in the minerals, or dirt (muddy) in the water?

Pure water is almost non-conductive.The addition of minerals/salts raises the conductivity to where it becomes lethal. See http://www.lenntech.com/water-conductivity.htm or http://kywater.org/ww/ramp/rmcond.htm.

 

[quogueelectric]

There is an anti grounding group within us that feels that grounding is more dangerous than it is worth. Maybe they have been beating the wrong drum.

 

[George Stolz]

There is an anti grounding group within us that feels that grounding is more dangerous than it is worth. Maybe they have been beating the wrong drum.

What do you mean?

 

[Rockyd]

Mike holt has a section on his DVD of Grounding VS Bonding on saltwater, and freshwater drownings/water electrocutions, Also if you go to miscellaneous on Mike's opening page, type in drowning (in the newsletters search section) there is a lot of research being done to understand water electrocutions.

Electrocution becomes a whole different issue when it is more than a "surface contact".

 

[Legrand]

Sounds like someone grounded directly to the motor, instead of the inverter, which is the way to avoid this, I think.

 

[roger]

What do you mean?

Maybe a case of PWI

Roger

 

[Buck Parrish]

Sounds like someone grounded directly to the motor, instead of the inverter, which is the way to avoid this, I think.

I guess the hull of the boat should be grounded , too.
Here is the link on the story.


http://www.mikehlot.com/newslettersphp?action=display&letterid=69

 

[Buck Parrish]

Try this link. It is the lattest news letter .
"The electric shock drowning of Samanthe Shepley"

www.mikeholt.com/newslettersarchive.php?listall&back=articlecategories.php

At "New Letters Articles" Click on - Back To Menu.
Then "All Newletters." It's the top one or two articles.

 

[don_resqcapt19]

It is my opinion that one of the problems with bodies of water and an electrical fault is the voltage gradient created by the resistance of the water and that in many cases wet skin is a better conductor than the water. The wet body "shorts" out the voltage gradient permitting more current to flow across the wet skin.

 

[jim dungar]

There is an anti grounding group within us that feels that grounding is more dangerous than it is worth. Maybe they have been beating the wrong drum.

I definitely do not want to go OT, but are you talking about the group that feels every conductive path needs to be bonded to create an equipotential plane versus simply making a connection to dirt?

This boat and marina connection definitly need to have their bonding investigated.

 

[winnie]

It is entirely possible in a case such as this that standard grounding and bonding techniques actually made the problem worse.

Standard techniques would have effectively bonded the boat hull, via the various EGC and bonding connections, all the way back to the utility primary neutral.

Some upstream fault could raise the potential of this bonded metal system relative to the surrounding earth, without any wiring fault at the boat itself. When the boat is connected this would cause current flow between the boat hull and the water. A GFCI would provide no protection, because it would neither sense nor open the EGC connection.

Of course, it is far more likely that some local fault, either on the boat or in the marina system, caused the problem.

-Jon

 

[Buck Parrish]

It is entirely possible in a case such as this that standard grounding and bonding techniques actually made the problem worse.

Standard techniques would have effectively bonded the boat hull, via the various EGC and bonding connections, all the way back to the utility primary neutral.

Some upstream fault could raise the potential of this bonded metal system relative to the surrounding earth, without any wiring fault at the boat itself. When the boat is connected this would cause current flow between the boat hull and the water. A GFCI would provide no protection, because it would neither sense nor open the EGC connection.

Of course, it is far more likely that some local fault, either on the boat or in the marina system, caused the problem.

-Jon

I agree, I was wondering if a solid #8 attached to the hull back to the main would help. Like on a hot tub. This of course would have to be taken off every time the boat left.
It wouldn't be prudent.

 

[dbuckley]

Although it sounds like the assertion that "Evidently the hull became energized" is correct the question is why, and I see two obvious scenarios.

It could be a local fault with a lost EGC, in which case a GFCI on the shore power feed would have saved this little girls life.

The alternative scenario is that the EGC to the hull was fully intact, and a potential was imported from (possibly far,) far away. No electrical fault with the boat or the shore supply.

In really wet places a a transformer SDS with no bond to the secondary, local ground rod and GFCI is so much safer than connecting up to the "real" multi grounded neutral through bonding.

 

[brother]

Would an 'isloation transformer or ungrounded system' made any difference here?? Seems like that might have helped here, if there wasnt a referrence to ground/grounded conductor here. Seeing how there was no gfci protection.

 

[don_resqcapt19]

...
In really wet places a a transformer SDS with no bond to the secondary, local ground rod and GFCI is so much safer than connecting up to the "real" multi grounded neutral through bonding.

That would require some major code changes, as that installation would not be permitted by the NEC rules.

 

[wawireguy]

"This boat and marina connection definitly need to have their bonding investigated."

You can bet your last dollar this is going to be thouroughly investigated by a team of lawyers..

 

[220/221]

Several years ago one of my clients daughter was killed and her husband hospitalized when the mast of their sailboat came in contact with an overhead power line at a new marina. Very sad and very stupid. Somebody really dropped the ball.

 

[iwire]

I agree, I was wondering if a solid #8 attached to the hull back to the main would help. Like on a hot tub. This of course would have to be taken off every time the boat left.
It wouldn't be prudent.

There is no requirement that the bonding conductor of a hot tub run back to the main.

With either the boat or hot tub the EGC run with the circuit supplying it is all that is required or needed.

 

[sparky59]

Boat docks are very dangerous. Electricity everywhere and lots of water to cause corrosion. There was a case in my area a few years ago. A man bought a new houseboat and the plug on the power cord didn't match the receptacle. So he went to the supply house and bought one that would work. He decided to install it himself and got the wires crossed. when he turned the power on his wife and daughter were sitting on the back boat deck with their feet in the water. Both died of electrocution. A very sad story.