6 Gauge Wire Clamped to Cold Water Copper Pipe Below Washer Box. Why?

[Fragile Bill]

I cut out a section of wall as the first step towards replacing my washer box. There is an insulated copper wire clamped to my copper pipe on the cold side. There is a 15 amp outlet about two feet from the washer box and a 20 amp outlet about four feet from the washer box. Both outlets are three prong and therefore grounded, so I don't expect the wire to have anything to do with them. My house was built in 1978. Does anyone know the purpose of the wire? Thank you!

 

[Twowaxhack]

It bonds the copper to the electrical system. Leave it be.

 

[Fragile Bill]

It bonds the copper to the electrical system. Leave it be.

Thank you! I have to cut the copper supply pipes and the two inch pvc drain pipe to replace the washer box. So I can't leave it be, but I can of course reattach it after the new box is in. Where does the wire connect on the other end?

 

[Twowaxhack]

Thank you! I have to cut the copper supply pipes and the two inch pvc drain pipe to replace the washer box. So I can't leave it be, but I can of course reattach it after the new box is in. Where does the wire connect on the other end?

It connects to your electrical system.

In your case I would use automotive jumper cables to temporarily connect to the wire to the copper pipe below where I would be working.

 

[Fragile Bill]

It connects to your electrical system.

In your case I would use automotive jumper cables to temporarily connect to the wire to the copper pipe below where I would be working.

Thank you! I will do that. Does the other end of that wire likely connect to the ground wire in one of those two outlets that I described in my original post?

 

[Twowaxhack]

Thank you! I will do that. Does the other end of that wire likely connect to the ground wire in one of those two outlets that I described in my original post?

No, it most likely goes to the main electrical panel or possibly a ground rod. Realize, I’m just a plumber, you could consult with a licensed electrician.

 

[BlueSkyHigh]

It bonds the copper to the electrical system. Leave it be.

And, hopefully, to “earth” ground.

 

[Twowaxhack]

And, hopefully, to “earth” ground.

Well yes, it’s part of the ground/bonding system.

 

[MicEd69]

Both outlets are three prong and therefore grounded

My interpretation of what you wrote is that because the outlets are three prong, you "know" they are grounded. That is not the case by any stretch.

There are thousands of 3-prong outlets that are installed with NO wiring connected to the ground at all, and there are thousands that have a jumper between the neutral and the ground on the outlet. Neither of those approaches are safe or up to any code.

And since you mention that the two outlets are two different styles, one 15 amp and one 20 amp, and you noted that they both were tree prong, I'm thinking you may have some two prong outlets in this house as well. You've found a 6-gauge wire connected to the cold-water line to your washing machine, which is not usually where the ground for the main electrical panel is found. It is normally connected to a primary water line near the electrical panel. And since you did not mention that your electrical panel is close by and are questioning the wire's purpose, I'm thinking the line to the washer is not particularly close to the panel.

So, while that wire could end at the electrical panel, it just as easily could end at a row of three prong outlets. #6 is pretty big wire, but I've seen where good meaning people have installed a large wire as a ground path for new outlets where existing two wire power and neutral cables were reused. Grounding them to a cold-water line isn't per code, but it does make the outlet checker read correctly, and is safer than using a jumper between the neutral and the ground on the outlet.

 

[Fragile Bill]

My interpretation of what you wrote is that because the outlets are three prong, you "know" they are grounded. That is not the case by any stretch.

There are thousands of 3-prong outlets that are installed with NO wiring connected to the ground at all, and there are thousands that have a jumper between the neutral and the ground on the outlet. Neither of those approaches are safe or up to any code.

And since you mention that the two outlets are two different styles, one 15 amp and one 20 amp, and you noted that they both were tree prong, I'm thinking you may have some two prong outlets in this house as well. You've found a 6-gauge wire connected to the cold-water line to your washing machine, which is not usually where the ground for the main electrical panel is found. It is normally connected to a primary water line near the electrical panel. And since you did not mention that your electrical panel is close by and are questioning the wire's purpose, I'm thinking the line to the washer is not particularly close to the panel.

So, while that wire could end at the electrical panel, it just as easily could end at a row of three prong outlets. #6 is pretty big wire, but I've seen where good meaning people have installed a large wire as a ground path for new outlets where existing two wire power and neutral cables were reused. Grounding them to a cold-water line isn't per code, but it does make the outlet checker read correctly, and is safer than using a jumper between the neutral and the ground on the outlet.

No, I have no two prong outlets in my house. My service panel is in the garage and my utility room (washer and dryer) is adjacent to the garage. I'm guessing it's 10 feet between the service panel and this particular cold water pipe.

I have read that the NEC began requiring grounding rods in 1978. My house was built in 1978. I have looked for a 1/4 inch diameter wire outside the house in the vicinity of the electric meter going into the ground and have not found one.

I put this same question on an electrician's online forum and the consensus so far seems to be that that water pipe is being used as the grounding electrode conductor for my service panel. Today it is required to be located within five feet of where the water service enters the house. But one electrician stated that that condition did not exist in 1978.

Also, it was stated that code does not permit such a connection to be concealed behind drywall. There should have been an access panel.

 

[Fragile Bill]

Picture (a) is a closeup of the wire that is clamped to my water pipe. I just now went into my service panel to look for "Keen Wire 6 AWG". See picture (b). The ultimate question is whether I can safely remove the clamp, replace the washer box, and then reattach the clamp. It sounds like the answer is "probably".

 

[MicEd69]

Yes, but when that is disconnected, you don't have a grounded electrical system. If you just need to move the clamp downstream a bit, you can loosen the clamp and try to keep it in contact with the pipe, slide it down, and tighten it back down. But as long as there is not an electrical event, you should be fine even if you have to remove the wire and reconnect it. Just don't come between the wire and the pipe with any part of your body.

 

[Twowaxhack]

Yes, but when that is disconnected, you don't have a grounded electrical system. If you just need to move the clamp downstream a bit, you can loosen the clamp and try to keep it in contact with the pipe, slide it down, and tighten it back down. But as long as there is not an electrical event, you should be fine even if you have to remove the wire and reconnect it. Just don't come between the wire and the pipe with any part of your body.

Jumper cables work great.

 

[MicEd69]

Yes, you can just peel off some of the insulation so you can clamp a jumper cable on the wire and then the other end to the copper pipe upstream of where you are cutting it before removing the ground clamp if you are concerned about an event happening when you move the clamp.

 

[RDKirk]

Hmm. We had our house (built 1960, low unimproved crawlspace) re-piped with PEX just a few weeks ago. The plumbers just replaced the supply lines with PEX, attaching to the copper lines descending from each fixture down to the crawlspace supply lines.

That means each fixture is electrically standing alone and no longer part of a grounded system, because I seriously doubt the plumbers individually grounded each fixture or ran a jumper between all the fixtures of the house. They did supply me with photographs showing each connection.

All of the electrical receptacles in the house are GFCI receptacles because the electrical system was originally ungrounded and many of the circuits still are ungrounded (although those close to plumbing fixtures have been grounded, but still have GFCI receptacles).

Do I have anything to worry about?

 

[MicEd69]

Not at all. The grounding we are talking about is for the electrical panel and your fixtures are not a part of that.

And using GFCIs is the way to bring your electrical up to code when your distribution wiring has no ground wire.