Ground clamp to water line but on threaded pipe

Looks like the ground clamp is on a short threaded pipe section. There is copper throughout the crawlspace. To me, the teflon tape breaks the conductivity to the underground copper and should be located on the left underground section of pipe. What do you think?

The ground clamp is not typically designed to clamp on a threaded nipple – this would be atypical use of the clamp. There can also be no interruption of electrical continuity and as you mentioned teflon tape can indeed impede the current. It’s questionable at best, an electrician should evaluate and approve this hackery :slight_smile: BTW, I recommend installation of supplemental electrode whenever ground water pipe is the only grounding electrode.

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As Simon stated above, it’s not the right way to ground the system.
As stated, the Teflon tape, but also the paint will prevent a bond.
And yes, main lines are not to be used as a primary ground due to the amount of plastic pipes in use today. 10 feet of continuous metalic pipe is required for a proper ground, and one can’t visually tell if the line was previously replaced a foot outside of the foundation wall with plastic.

Unless I see an Ufer ground or a ground rod at the exterior connected with a EGC from the meter socket panel or from the service panel, I will always call out the grounding system as inadequate.

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If you move it to the left then the the pipe to the right is not bonded.

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I’d be willing to bet that teflon tape does not interrupt the continuity of the connection. I think it really just seals in gaps and the threads end up resting tight on the metal. Paint will however (and rust) unless you scrape it off. One way to tell is check it for continuity with an ohm meter…

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I realize there is some gray area in this one. I appreciate the great thoughts and insight.

I agree that most likely its bonded even with the teflon tape and most likely it’s copper underground but that’s not my job to assume. I wrote it up as a potential grounding issue that should be evaluated by a licensed electrician as it is an unusual and somewhat suspect installation.

Thanks guys.

I agree, that bond should be on smooth pipe which had been lightly sanded and cleaned to ensure good contact when possible. However, rebar seems to be the exception in many cases. Judgement call.

Is clamp galvanized like the pipe its attached to? Isn’t there a “dissimilar metal” issue with attaching Copper to Galvanized pipe? I we think the grounding clamp should be brass and attached to the copper pipe.

A second thought might be that the threaded pipe is brass and was painted gray with everything else…copper supply pipe covered or added afterward?

You’re correct that the pipe clamp has to be listed for the conductor material type (copper or aluminum) and the type of pipe it’s attached to.