Volts500,

There is no such thing as a "central earth ground" unless only _one_
grounding electrode is used.....a very poor practice in itself (with the
possible exception of a metal well casing)....much better to have
_multiple_
grounding electrodes bonded together. All grounding electrodes are bonded
together to form a _single_ grounding electode _system_. The ground rod
that is being installed is merely a _supplement_ to the main grounding
electrode.......in this case the metal water pipe. Not a good idea to try
to dump all that on a single ground rod.......a single ground rod will in
fact become a choke to lightning trying to get into the ground. That
single
ground rod should be supplemented by at least another ground rod 6 feet
away
(or use a delta ground), or a ground ring can be installed with a minimum
#2.....and catch the cable TV while you are at it.

I guess I could be convinced to install 2 rods. I'm doing the work to
install the first.


The basic idea is too run an unbroken GEC from the main panel to the
underground water pipe (min. #4) and suppliment that with a ground rod (or
two). Then bond all systems together.

If I plant the ground rods just outside the wall of my service panel, I'd
have to dig 20 yards over and eight feet down to bring the #4 to the water
pipe. If I run #4 from the ground bar to the water pipe from inside the
house and then do two ground rods, won't that be enough?

The idea is that when all the
systems are bonded together, ALL will come up to the same voltage (can be
ma
ny thousands of volts), thus _not_ allowing a destructive current flow in
equipment served from different systems....like a modem. Don't forget to
jumper around the water meter and bond the hot water.

If I bond the hot water pipe, I'm guessing I would do it the same way as the
cold (from the inside).

What do you mean by "jumping around" the water meter?

Bottom line, electric system grounding is a very misunderstood subject and
needs to be done by people who know and care about how to install it.

Don't get me wrong. I trust the advice here or I wouldn't be here. But
here's the bottom line for me. Whatever electrician the previous home owner
hired didn't do the job right, the electrician I hired to inspect the home
before I bought it didn't see the problems, and the electrician I'm
currently paying to fix things now is contradicting the advice I'm getting
here. I guess I could go to the yellow pages again, but at this point I if
I don't know what "right" is, I don't think I'll ever have peace of mind
over what work is finally done.

You still have your inside metal gas line to deal with.......you should
call
your gas co. to see if they allow an (inside) connection to the electric
grounding system as required by NEC.

I had the gas guy out ther other day. Although the pipes I see are metal,
he said the lines underground were plastic, but I'll make the call to make
sure.


I hope that after going through all that trouble that you are also going to
install a lightning arrestor at the electric meter or service panel.

I'll look into that, but it seems like overkill at this point.

Then
use a decent point of use surge protector for the computer that has
provision for power _and_ phone....cable too if you ever use a cable modem.

I have a $35 surge protector I use for electrical and telephone.


Also, since you said that you have a subpanel in another thread, you should
check to see that the subpanel is fed from the main panel with a _4_ wire
feeder (2 hots, neutral, equipment ground).

Power enters the house in the form of two hot conductors going to the single
100A breaker box
and then exit the box, going to the modern service panel. The neutral
conductor coming into the house
goes to a short metal "bar" which is bonded to the box itself, and then it
also leaves the box and goes
to the neutral bar of the modern service panel. From inside the 100A
breaker box, from that same short metal "bar" there are also two 4 gague
bare copper conductors that leave the box. Currenly, one leaves the box and
goes through the basement wall and out to earth ground. The other copper
conductor leaves the box and goes to the ground bus bar of the modern
service panel.

Thanks keeping me straight on the details.