wires and splices and circuits Oh My!

[davedottcom]

Re: wires and splices and circuits Oh My!

Originally posted by rattus:
Sounds like an open neutral in the wiring to the boat.

Are you replying to my story or the one about the person swimming?

I know for a fact that the original problem I trouble-shot was an open nuetral in the service that fed the dock panel. There was 185+ volts on one leg and 60 something on the other... again, depending on what loads were applied.

As far as getting shocked while completely emersed... Is it possible that the human body is More conductive than the water itself? In other words the electricity is taking a path of lesser resistance? Just a guess!?

 

[jbwhite]

Re: wires and splices and circuits Oh My!

Originally posted by davedottcom:
As far as getting shocked while completely emersed... Is it possible that the human body is More conductive than the water itself? In other words the electricity is taking a path of lesser resistance? Just a guess!?

Just another guess. Water (H2-O ) in its pure form is not a conductor at all. What makes the water that we encounter a conductor is the mineral content. I can see the possibility that there are various gradiants of water in such a situation as discribed.

what i mean is that there could be areas of different mineral content, and the human body could become the conductor from one high concentration area through a less concentrated area to the next higher concentrated area.

 

[bthielen]

Re: wires and splices and circuits Oh My!

That does sound reasonable. Even if the body was a lower resistance than the surrounding water, there needs to be a potential differnce from one point of contact to another in order to promote current flow. If all the water is of the same material in its entirety, then it seems that this potential difference would not exist. JB's thoughts seem to hold water (punn intended).

Bob

 

[rattus]

Re: wires and splices and circuits Oh My!

Our insides are highly conductive, I would guess about the same as salt water. It matters not which is more conductive, the current will divide accordingly.

Usually when we touch live wires, the contact area is small, the conductivity of the skin is relatively high, and we may not even feel the current.

But, if we are in salt water, the contact area is large which lowers the skin resistance. A smaller voltage would be required to create harmful currents in the body.

Obviously, there are electrical currents in the water, probably from an ungrounded boat hull.

 

[rattus]

Re: wires and splices and circuits Oh My!

Originally posted by bthielen:
That does sound reasonable. Even if the body was a lower resistance than the surrounding water, there needs to be a potential differnce from one point of contact to another in order to promote current flow. If all the water is of the same material in its entirety, then it seems that this potential difference would not exist. JB's thoughts seem to hold water (punn intended).

Bob

The water acts as a 3-dimensional voltage divider. Its resistance is neither zero nor infinite! If there are electrical currents in the water, one could immerse probes a foot or so apart and read the voltage drop.

[ December 29, 2005, 03:52 PM: Message edited by: rattus ]

 

[rattus]

Re: wires and splices and circuits Oh My!

Another thought:

The boat in question may not be the offender. It may simply serve as a voltmeter probe. The electrical current may come from other sources.

Rattus

 

[iwire]

Re: wires and splices and circuits Oh My!

Originally posted by hardworkingstiff:

Originally posted by jes25:
I knew that, for some reason I thought there was something specfic to baot docks. Seems like there should be.

555.19(B)(1)

That again depends.

Part of 555.1 Scope

Private, noncommercial docking facilities constructed or occupied for the use of the owner or residents of the associated single-family dwelling are not covered by this article.