Grounding a house via overhead suspension cable?

[DerbyDad03]

I'm renting a vacation house on the Outer Banks of NC. It's one of those
stilt built houses.

I was looking at the service entrance and noticed 3 wires going into the
pipe. 2 are obviously power but the 3rd is clamped to the suspension cable
that carries the service wires from the pole to the house. I followed that
cable back to the pole and found that it was attached to a tap on the
transformer, as was the suspension cable from 2 other houses.

From that tap, it looked like that there was a fairly small wire that ran
to the same type of suspension cable which ran from pole to pole along the
street.

At the house, there was no ground wire going into the ground like I'm used
to seeing, so I am assuming that they are using the suspension cable as the
ground wire.

Is this method used because the house is on stilts (i.e. in an area prone
to flooding) or is that just a different method of running the ground, a
method that could be used on any house, anywhere?

[RBM]

On 8/8/2012 9:52 PM, DerbyDad03 wrote:
That's pretty standard overhead triplex cable. The bare wire, which has
a steel core and is the suspension cable, is the neutral. The neutral is
grounded at the poles and at the houses.

[Steve Barker]

On 8/8/2012 8:52 PM, DerbyDad03 wrote:

I would still expect to see a ground at the house. Are you sure there's
not a bare copper running down one of the stilts?

--
Steve Barker
remove the "not" from my address to email

[DerbyDad03]

RBM <rbm2@live.com> wrote:

Where should I expect to find the ground at the house? There's nothing
going into the ground (earth) from the meter box.

[fred.flintstone@thecave.com]

On Thu, 9 Aug 2012 01:52:12 +0000 (UTC), DerbyDad03
<teamarrows@eznet.net> wrote:


Unless those stilt homes have special codes, There *should* be a ground
at the house. It might come off the bottom of the breaker box.

That suspension cable serves as the neutral as well as ground. The
transformer pole should also have a bare wire coming down the pole to a
ground rod.

[RBM]

On 8/8/2012 11:51 PM, DerbyDad03 wrote:
Most likely coming out of the main service panel.

[DerbyDad03]

RBM <rbm2@live.com> wrote:

After further inspection, I found a ground wire coming out of the bottom of
the meter box. The meter is mounted on some PT wood and there's a space
between it and the house. A ground wire comes out of the back bottom and
then goes up behind the meter and comes out of the side where it's tied to
the cable TV ground and then goes into the earth.

It's not as big as I was expecting, maybe 8 gauge? 10? I was looking for a
much larger cable like I'm used to seeing at home. Something about the same
size as the suspension cable, which is why I thought it might be the
ground.

Thanks for the explanation.

[gfretwell@aol.com]

On Thu, 9 Aug 2012 15:17:45 +0000 (UTC), DerbyDad03
<teamarrows@eznet.net> wrote:



It is based on the size of the service entrance cable.

8ga is the minimum for 100a service, using 4ga or 2ga SE cables.
A 200a service typically uses 4ga.

You do run into a conundrum. If the grounding electrode is just a rod
or two you are only required to run a 6ga to it because that is all
the current it will sink. Then the inspector has to ask, which rule
applies.