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.
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
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
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. ;)
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
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
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.
First I don't know, nor did I look up the code. However I strongly
suggest that you always should follow the code, especially when you don't
understand why it is code. They don't write code without good reasons.
My guess (SWAG) is that at least some of those devices that are being
bypassed may be damaged by the leakage and the larger cable will make sure
the cable is the path of least resistance to protect them.
When using two ground rods, they should be seperated by a minimum of 6 feet.
Also, 6 AWG wire is required when using
ground rods, not 10AWG. If the work is done "to code" then this is how it
should have been done.
Did they pull a permit? Better verify what they did and what wire sizes
You know I wasn't asking for a critique of the job, I was asking WHY the
size difference between the two. Or do you not know, but you felt compelled
to answer anyway?
In any case I got the answer I needed a couple posts back. Thanks for
Sorry, didn't mean to make you mad, that wasn't the intent. I was just
pointing out what
the code requirements are vs. the information you supplied. I felt it was
more important to
point out a potentially unsafe situation than to state the reason for
differing wire sizes.
This is a newsgroup - it's filled with people that I've either pissed off,
offended, insulted, or harassed.
So far as I'm concerned - everything that occurs here is water under the
bridge when the day is done.
The National Electrical Code requires that ground rods should be no less
than 6' apart. However tests have proven that ideally for two eight foot
ground rods a distance of 16' or more is best. I think that the minimum
wire size for supplementary ground rods is #6. Depending on the size of the
service your bonding jumpers can be #8 or #6.
I hope that this work will be inspected.
NEC and engineering studies have determined that a ground rod cannot
dissipate any more electrons into the earth in a given time than can be
carried by a #6 copper wire, thus there is no need to use a wire larger
than a #6 copper for ground rod, pipe or plate electrodes.
Now I'm curious........what was used to ground your electric system
before all this?
The galvanized pipes were undoubtedly connected to an underground metal
water pipe that was metal to metal connected to a metal well casing or a
public water system consisting of literally miles of pipe and you call
that nothing. Underground metal water pipes of significant length or
depth make a much better grounding electrode than those two driven rods
you are asking about. The entire purpose of the two driven metal ground
rods is to provide a backup to the water piping in case it is opened
during plumbing work or replaced with plastic during a future repair.
If your entire home were piped with plastic so that there was no
metallic piping inside the home and the only metal piping was the
underground metal water piping that supplies the building the code would
still require that underground metal water piping of twenty or more feet
in length be used as a grounding electrode.
"This alternating current stuff is just a fad. It is much too dangerous
I see where you are coming from, and I have a feeling that this has been
discussed at length ad nauseum, but I'm gonna ask anyway.
The supply pipes feeding my house are plastic not metal (I've been watching
them install them all summer long, those 6"+ blue/green nylon plastic
pipes. - I'm presuming those are water mains, I guess they could be sewer
lines too but sewer lines are concrete usually. So how would bonding to the
water mains help there? At that point there is no metal pathway except from
my house to the meter. Not that I'm disputing your claim mind you, when I
convert my house to PEX I still intend on having the inlet cold water pipe
be copper - if only so that it's solid and secure. But if the water mains
are plastic pipe, how would my house be bonded then?
Anyways we're getting off track here, so if you want to just point me in a
good direction I can take it from there so we don't have to go over this
I imagine he is talking about the pipe at the street
Green pipe is sewer, blue pipe is potable water, purple pipe is
It is true that any new water pipe will be plastic but in older
neighborhoods it is metal.
The larger grounding electrode conductors for water pipes is from
those days when a water pipe was as good an electrode as you could
get. The code never backed off of that, in spite of the fact that
water pipes can't be trusted anymore and must be suplimented.
If you do still have a 3/4 or 1" copper pipe going to the steet it is
an excellent electrode and will sink every amp a #4 copper wire could
source. Just be sure the connection is on the street side of the meter
or anything else that could insulate it.
"Recycled water" is a general term for non-potable water recovered
from ground water, surface ponds or the effluent of a sewer plant. It
is used for irrigation and in some real water hungry places, to fill
As bad as that sounds, a swimming pool treatment system is expected to
treat a certain amount of poo and pee. People are dirty creatures.
In real life most water people use is recycled and virtually all the
water is the same water we have had all along. People in Chicago pee
in that river and send it on to Peoria who treat it, drink it, pee
back in the river and send it on. Imagine how many people have peed in
the river by the time it gets to New Orleans.
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