Re: [PSUBS-MAILIST] Thoughts on Volts and H2O was Compensation

["Gary R. Boucher" <protek@shreve.net>]

David,
     To answer your question, 120-volts as you would find it in a wall 
outlet is actually a single "hot" wire that carries a voltage in reference 
to the neutral wire.  The neutral is, or is "supposed" to be at ground 
potential.  There is also a protective ground that is "supposed" to be at 
ground potential.  A circuit is made when the hot wire comes in contact 
with anything that is attached to earth ground.  Most people think of 
current flowing in a wire only, but it can flow through water if it has 
enough ions.  The hot wire supplied current that fanned out through the 
water to the bottom of the lake which is earth ground.  The kids just got 
in between.  The human body is more conductive than the water that 
surrounds it so the current tends to flow through the body more than the 
water.  It is a very difficult problem in electrical engineering to 
calculate the current densities in a situation like that.  You would have 
to model it or simulate it with a computer.
     In theory, if you drove a metal rod into the ground and put a light 
bulb between the hot wire of the 120 line and the ground rod it will 
light.  Usually ground of that nature have some voltage drop and it's not 
the way to go.  Like it is dangerous to run just one wire and hope your 
ground is good enough.  Years ago they used to run telephone and even 
telegraph hookups with one wire using the ground as the return.  It's an 
interesting subject for an EE.

GB

> >     One last thought.  I recently saw on some TV show a reenactment of a
> >near electrocution where this kid jumped off in a lake from a pier and
> >suddenly stopped moving.  The problem was a 120 volt line hanging into the
> >water supplying power to a pier light.  I seem to remember another person
> >jumping into the water and having the same problem.  They got the power off
> >and I believe both lived.  Had that been a saltwater scenario they would
> >have probably died.  Killed by low resistance!!!
> >
> >Gary Boucher
>
>
>Gary,
>Thanks for the wise words on electrocution and volts and amps and such. 
>(Although Dave's story was much, much funnier!).
>
>I like to think I'm pretty safe with the 12-volt circuits through most of 
>my house, but I manage to be pretty careless sometimes, and boy can you 
>get some pretty big sparks and some pretty warm wires when you make a boo-boo.
>
>In the part about the wire in the lake above... how could the people 
>diving in have become part of the circuit, if the wire was just hanging in 
>the water? Or did they brush against it on the way in? Huh? I don't get it.
>
>--
>David
>Osage MN USA
>buchner@wcta.net - http://customer.wcta.net/buchner