On Wed, 2005-02-23 at 14:13 -0600, Mike Hord wrote:
> One other thing puzzles me.  What good does it do to tie
> the neutral to the ground rod outside, then run two seperate
> wires to each outlet?  Is the benefit derived from the fact that
> the green/bare wire is nominally supposed to be a 
> non-current-carrying wire?  That proves helpful in ground-fault
> detection schemes, but how so otherwise?

Actually this one is very simple: safety.

Consider this: you have a computer with a metal chasis. The metal
chassis is normally connected to the green wire. Consider there's a
fault in the supply that causes the hot to hit the chassis: boom,
breaker blows, all is good.

Now consider the case where there is no green wire: you have two
choices: 

- connect the chassis to nothing (you can easily see what happens if you
happen to touch the chassis with hot in contact with the chassis).

- second choice - connect the chassis to the neutral. Sounds good right
since the neutral is connected to the same point as ground used to be
connected. But, what happens if the neutral wire is broken somewhere in
the house? The computer won't turn on. What will you do? Probably end up
touching the chassis, which is now at pretty much line voltage (even if
the PC power supply switch is on all it takes is one device on that
neutral leg to be on, a light bulb will do it). Not a good end for
you...

TTYL
 

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