Grounding of main distribution panel?

Donn Lindorfer · 12-14-2009, 08:07 PM

I have seen the main panel grounded to the cold water pipe, and to a grounding rod, but I have never seen it grounded to the pipe that goes to the meter before. Is this an acceptable method for grounding the main panel? I sure don't think so, but I thought I would ask to be sure. The picture I have included shows what I am refering to. (Its a little hard to see, but the ground wire is connected to the pipe with a weaver clamp.) Interestingly enough, the ground wire also goes to a cold water pipe that has been physically cut and abandoned. Appreciate your feedback.

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**Jim Luttrall** · 12-14-2009, 08:16 PM

I am assuming you mean the electric meter conduit.
No that is not appropriate for a grounding electrode, bonding yes, GEC no.
There should be bonding to ALL metal piping in the house and grounding to an approved grounding electrode (I.e. buried water pipe, driven rode, etc.)

**Ken Rowe** · 12-14-2009, 08:44 PM

Hey Donn,

The ground wire should pass through that clamp. It's basically a bonding clamp to ground the conduit. Then the ground wire should continue on to a cold water pipe with a bond jumper over the water meter.

The end that is abandoned was most likely cut off the pipe when a well was removed. I see it a lot in older houses. Repairs by a qualified electrician are in order.

Donn Lindorfer · 12-14-2009, 10:07 PM

Thank You guys for your help!! I'm surprised this was missed since the basement was recently rewired when it was finished. (Of course I am not sure who wired it...)

**John Kogel** · 12-14-2009, 11:23 PM

Originally Posted by Donn Lindorfer

Thank You guys for your help!! I'm surprised this was missed since the basement was recently rewired when it was finished. (Of course I am not sure who wired it...)

We can't be sure it WAS missed, unless you have pics of inside the service panel. We see the bare copper bonding wire coming out of the panel, clamped to the conduit and then continuing off to the upper left. It may go to the cut water pipe from there, can't tell.
That doesn't mean there is no grounding conductor, that is another wire, probably stranded copper, from a ground rod to the panel.

**Jon Errickson** · 12-15-2009, 07:11 AM

Ken -- wouldn't it still be OK if it's connected to that pipe that likely goes out to an abandoned well? (i've seen that a bit too around here.)

Thanks.

**Ken Rowe** · 12-15-2009, 07:40 AM

Originally Posted by Jon Errickson

Ken -- wouldn't it still be OK if it's connected to that pipe that likely goes out to an abandoned well? (i've seen that a bit too around here.)

Thanks.

It should be fine as long as the ground wire and the well pipe are still intact. The problem comes when the well pump gets removed and the well capped. Many times I've seen where they just cut the pipe off along with the ground wire and just leave the wire hanging. Most people removing wells have no idea what that wire is for.

**Jon Errickson** · 12-15-2009, 08:18 AM

Thanks Ken. Just a follow-up question: In my house for instance, the well was capped out in the yard, so i have no way of seeing it. But the grounding wire is connected to the cut-off pipe that used to come into the home from it, towards the base of my foundation near my SE. The pipe is cut-off a few inches after it comes into my house, but there's enough room for the grounding wire to be properly clamped to it. This should be fine, right? (i also have a grounding wire connected to a grounding rod).

You're referring to the old wells we sometimes see under the front stoop, right?

Thanks again,

Donn Lindorfer · 12-15-2009, 08:31 AM

Originally Posted by John Kogel

We can't be sure it WAS missed, unless you have pics of inside the service panel. We see the bare copper bonding wire coming out of the panel, clamped to the conduit and then continuing off to the upper left. It may go to the cut water pipe from there, can't tell.
That doesn't mean there is no grounding conductor, that is another wire, probably stranded copper, from a ground rod to the panel.

The wire that goes off to the left does attach to the old water pipe that is cut a few feet away. I have uploaded a picture of inside the box if that is helpful. Thank You for your feedback!

**Ken Rowe** · 12-15-2009, 12:51 PM

Originally Posted by Jon Errickson

Thanks Ken. Just a follow-up question: In my house for instance, the well was capped out in the yard, so i have no way of seeing it. But the grounding wire is connected to the cut-off pipe that used to come into the home from it, towards the base of my foundation near my SE. The pipe is cut-off a few inches after it comes into my house, but there's enough room for the grounding wire to be properly clamped to it. This should be fine, right? (i also have a grounding wire connected to a grounding rod).

You're referring to the old wells we sometimes see under the front stoop, right?

Thanks again,

If I'm following you correctly the ground wire is connected to the pipe going to the well, but that pipe is no longer connected to the water pipes of the home. This would be incorrect as the water pipes in the home should be grounded and bonded to the other metal pipes (gas, conduit etc).

Assuming your water pipes are metal, the easiest thing to do would be to clamp your ground to an interior water pipe and install a bond jumper across the water meter.

**Jon Errickson** · 12-15-2009, 01:22 PM

Sorry, I should have mentioned that I have another grounding wire connected to the pipes.

Do you need the jumper wire around the water meter if the main water pipe coming into the home is plastic? (no, right?)

**Ken Rowe** · 12-15-2009, 01:50 PM

Originally Posted by Jon Errickson

Sorry, I should have mentioned that I have another grounding wire connected to the pipes.

Do you need the jumper wire around the water meter if the main water pipe coming into the home is plastic? (no, right?)

Correct. So you've got a ground from the panel to the capped well supply pipe, a bond wire from the well supply pipe to the interior water pipes and a second ground wire from the panel to a grounding rod. Non-metallic water pipes from the city supply. If that's the case you'd be fine.

**Jon Errickson** · 12-15-2009, 02:31 PM

One last question, and then i swear i'm done. For the bonding of the gas pipes -- can you use one wire that clamps onto the gas piping, then continues on to the copper water piping (or vice versa), or do you need separate wires from the gas to the water and water to SE?

**Ken Rowe** · 12-15-2009, 03:17 PM

Originally Posted by Jon Errickson

One last question, and then i swear i'm done. For the bonding of the gas pipes -- can you use one wire that clamps onto the gas piping, then continues on to the copper water piping (or vice versa), or do you need separate wires from the gas to the water and water to SE?

One wire from the gas pipes to the water pipes should be fine.