Using the water pipe as an actual EGC

Interesting find today, and sadly not my first time seeing this.

Ah, not good!

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What seems to be the problem? The equipment bond is physically secured with solder.
What was the bond for?

Do you mean GEC? I see that often with older homes, they will run the GEC to the main water shut off, but I always recommend another means. Water lines should be the secondary, not primary


Was it soldered?

No to the GEC that is in picture 2 here.
Older home 2 wire system and installing EGC to copper water pipe instead of return back to the service panel

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If everything is bonded back to the GEC, I don’t think it would be an issue, as long as it is secure.
Even the diagram says it can be at any accessible point of the grounding system.

I would question the adequacy of the solder. Are each of those connection points sold, and holding up? The normal method involves a clamp. Also the bare ground wire should not touch the cast iron pipe. It should either be firmly clamped to, or isolated, from each metal service line.

@dhorton2 why do you say the water line should be the secondary and not primary? A water line on a public system certainly has more in contact with the earth than a rod.

Because the water line cannot be the only grounding electrode. If that water service was ever changed to plastic, they have no grounding.

Still doesn’t make that secondary to rods in my mind.

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My ‘bread and butter’ homes are “cold water pipe only” homes.
When their systems get upgraded, a “Secondary grounding” is added. That doesn’t downgrade the original to secondary. It remains as the Primary source with a secondary rod.

If the water main is metal and is in contact with earth for more than 10 feet, it is always the primary electrode. The only time it is not is when the water main is plastic. NEC requires the water main to be used as an electrode and be supplemented by at least 1 more electrode. That’s the way the code is written :slight_smile: The logic behind this is that you don’t install a water main to supplement any other approved electrode. The water main pipe comes first (thus being primary) and then you supplement (secondary) it with another grounding electrode.

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Yes, you are all right… I guess I was just trying to point out that it isnt allowed to be the only one. I always considered the water line as being another means of “bonding”, which made it a secondary in my mind

The NEC does not use the terms primary or secondary electrodes so IMO HI’s should refrain from using those terms at all. If the water pipe qualifies as an electrode then it’s used as part of the building GES (grounding electrode system). As already mentioned it cannot be the sole electrode as it must be supplemented by another electrode typically two ground rods or on new buildings a CEE. If you had a water pipe and a CEE would you still call the pipe electrode the primary?


I would consider the water main “primary” because it would be supplemented by CEE, not the other way around per NEC. This is not to say or imply that one will perform somehow better than the other.

I do agree, it can open a can of worms and lead to an argument. There is no reason to define an electrode as primary or secondary, it is not helpful, if anything will confuse.

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The primary/secondary terminology is confusing to say the least and is not supported by the code language so there is no reason to ever use it. I would disagree that the NEC would consider the water pipe the primary electrode as there is no such distinction made in Article 250. It states that all electrodes present must be used.

Having said that I can see how someone may consider the water pipe as the primary electrode because it must be supplemented by another electrode. I just think of it as if there is a water pipe electrode then you must have two electrodes. If there is a CEE and no water pipe then you only need one electrode.

Related… 2020 NEC Changes series: 250.68(C) Grounding electrode conductor connections - YouTube

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