"Tom The Great" wrote in message
...
On Mon, 25 Dec 2006 15:08:27 -0800, "Eigenvector"
wrote:

I asked the electrician why there was such a difference between the two
types of wires but never got an answer other than "It's code".

So when I had my earth ground installed in my panel, 2 ground rods ~4 feet
apart with a 10 gauge wire connected between them and the panel.

I think code now requires 6 or more feet and should have not been
smaller than 6awg coper, but I'm not beating up the details.


At the same time he installed bonding for the hot, cold, and gas pipes -
but
for this he used like 5 twisted strand 10 gauge wires - it was a HUGE
copper cable.

When I asked why the bonding got the big cables and the earth ground got
the
single 10 gauge he mentioned that 10 gauge is really all that is required
for good solid ground and that's what code called for. But he didn't
really
explain why the bonding required such massive wires. It's not like I
think
he cheated me on the copper, I trust the company he works for and he did
very good frugal work in the panel. I just kind of want to know - why the
difference in size? If anything I would expect the situation to be
reversed, the massive cable to the ground rods and the small wire to the
pipes.


IMHO:

I'm thinking you need to have the work looked at by a qualifed
electrician. The information you gave seems 'weird'. The bonding of
piping shouldn't require such thick cable. Unless you have some
monster water equipement.

Ok, now for some information. The cable going to ground rods aren't
sized to carry fault current. They are sized to stablize voltages
against transiants. The bonding of piping, and equipment(such as
ground wires in circuits) is designed to carry max ground fault
current back to the power source(the service panel, sub panel, etc)
and cause the over current protector (a breaker, fuse, etc) to open.
So you can see who one is to 'fix' voltage fluctuations, and the other
is to protect equipment and lives, which results in different concerns
(amps, etc).

Now this information was just an FYI, you need to have a qualified
electrician to check your system, if you have ANY concerns about it's
safety.

tom

The company that did the work was qualified and greatly respected in the
industry in my area. I trust the work they did. I may have the wire gauge
sizing off, it might in fact be 6 gauge, but I've never seen wire that thick
so I don't know for sure. All I know is that it wasn't 12 gauge or more. I
specified code work, he confirmed that everything he did was to code. I'm
not asking because I don't trust the work, but rather just out of curiosity.
Not slapping you down for answering so don't take offence, I'm merely
clarifying my position.

But your explanation of the purposes does help explain the sizing
differences to me.