Grounding Electrode System Question

[Jerramundi]

I think you are misreading the word "if" to mean you have a choice whether or not to use a qualifying underground water pipe as a grounding electrode. You don't.

It does NOT say "it has to be used as an electrode."

You're confusing an underground metal water piping system (1) QUALIFYING as an electrode (250.50) .....with (2) USING it as an electrode.

If it qualifies as one, it has to be bonded to the other Grounding Electrodes per 250.50.
This can be accomplished with a bonding jumper sized by 250.102(C)(1) and bonded to a local metal conduit (i.e. at the water heater) which is bonded to the service entrance enclosure and thus the other GEs per 250.104(A)(1)

Using it as an electrode invokes different codes

250.53(D)(1) requires continuity shall not be interrupted by the water meter. Now we have size a wire according to 250.66 and run it to the street side of the water main.

Different.

 

[Jerramundi]

Why would there be all these caveats... if used as an electrode if a situation did not exist where a metal water piping system was in place, but not technically used as an electrode, only bonded thereto.

 

[Jerramundi]

I always like to point out that bonding the water piping and using an underground water pipe as a grounding electrode are two different things, although you probably can kill two birds with one stone.

Thank you! At least I know I'm not alone in my interpretation, haha. Interesting debate though.

 

[ActionDave]

It does NOT say "it has to be used as an electrode."

Yes it does. That is exactly what 250.50 says.

250.53 uses the word "if" several places to describe how the electrode system is to be connected. "if practicable", "if multiple rods", "if used as a grounding electrode".

 

[don_resqcapt19]

It does NOT say "it has to be used as an electrode."

You're confusing an underground metal water piping system (1) QUALIFYING as an electrode (250.50) .....with (2) USING it as an electrode.

If it qualifies as one, it has to be bonded to the other Grounding Electrodes per 250.50.
This can be accomplished with a bonding jumper sized by 250.102(C)(1) and bonded to a local metal conduit (i.e. at the water heater) which is bonded to the service entrance enclosure and thus the other GEs per 250.104(A)(1)

Using it as an electrode invokes different codes

250.53(D)(1) requires continuity shall not be interrupted by the water meter. Now we have size a wire according to 250.66 and run it to the street side of the water main.

Different.

If there is at least 10' of metal water pipe in contact with the earth,, you have ZERO choice about using it as a grounding electrode. The language in 250.50 is very clear. It cannot be boded to local metal conduit at the water heater or any other location if it qualifies at a grounding electrode.

 

[electrofelon]

Thank you! At least I know I'm not alone in my interpretation, haha. Interesting debate though.

Hmmm, I don't believe I am agreeing with what you are saying

 

[LarryFine]

I agree that a water service (or any metallic pipe) that qualifies as an electrode must be connected as one.

An inside metallic pipe system must be bonded to, either coincidentally as above, or anywhere on it otherwise.

Interesting side twist: If I want to use a water service pipe as an electrode, is it incumbent upon me to prove it qualifies as one?

If, however, I don't want to use a water service pipe as an electrode, is it incumbent upon an inspector to prove it qualifies as one?

 

[Jerramundi]

Just to clarify.. what you're all arguing FOR... is indeed what I would normally do. I'm trying to avoid having to, for example, run a continuous #4 from the panel to the street side of the water main... and perhaps that is tainting my current read of the code wording.

I'm reading 250.50 as:
(1) Metal water piping exists that would be permissible to use as a Grounding Electrode
(3) Therefore it must be bonded to all other electrodes
... which simply means establishing electrical continuity between...
... and not necessarily a direct wire from Electrode #1 to Electrode #2.

When you say "use it as an electrode," I think continuous wire from the panel to the street side of the water main.

That's not what I get from 250.50. All I get from 250.50 is that if it's there, and qualifies as one, it must be bonded to all the rest.

 

[Jerramundi]

All 250.50 is saying is that a Metal Underground Water Pipe, that would be permissible to be used as a grounding electrode (per 250.52), must be bonded to any and everything else that would be permissible to be used as an electrode (per 250.52).

To me, that's not the same thing as saying "the metal water piping system is being used as a grounding electrode."

 

[LarryFine]

All 250.50 is saying is that a Metal Underground Water Pipe, that would be permissible to be used as a grounding electrode (per 250.52), must be bonded to any and everything else that would be permissible to be used as an electrode (per 250.52).

To me, that's not the same thing as saying "the metal water piping system is being used as a grounding electrode."

A metal pipe in contact with earth for ten feet or more must be used as an electrode; it's not optional.

 

[ActionDave]

When you say "use it as an electrode," I think continuous wire from the panel to the street side of the water main.....

You seem to be confusing grounding electrode with grounding electrode conductor.

 

[ActionDave]

.... All I get from 250.50 is that if it's there, and qualifies as one, it must be bonded to all the rest.

That is not what you said in earlier posts. Thirty minutes ago you were saying that a qualifying metal water pipe just needed to be jumpered to a metal conduit that feeds the circuit to a water heater.

 

[Little Bill]

If the metal pipe qualifies as an electrode, then it is an electrode and must be used, along with any other qualifying electrode.

 

[ActionDave]

... I'm trying to avoid having to, for example, run a continuous #4 from the panel to the street side of the water main... and perhaps that is tainting my current read of the code wording.

That's been obvious since your first post. Unfortunately you don't get to bend the words of clearly written code sections to fit your hopes for an easier installation.

I don't know what you mean by street side of the water main, but all you have to do is be within five feet of where the water line enters the building.

 

[LarryFine]

I don't know what you mean by street side of the water main, but all you have to do is be within five feet of where the water line enters the building.

I believe he means the street side of a meter. A jumper suffices if not, but the GEC must land within five feet of entrance, regardless of the meter's location.

 

[ActionDave]

I believe he means the street side of a meter. A jumper suffices if not, but the GEC must land within five feet of entrance, regardless of the meter's location.

That may be true but you would think that someone who spends so much time and energy quibbling over a two letter word in article 250 would be a little more clear about what he means when using words that don't appear anywhere in article 250.

 

[infinity]

250.53(D)(1) requires continuity shall not be interrupted by the water meter. Now we have size a wire according to 250.66 and run it to the street side of the water main.

Just to clarify I'll ask again, where in the NEC does it say street side of the water main?

 

[Fred B]

A metal pipe in contact with earth for ten feet or more must be used as an electrode; it's not optional.

250.50 States that any permited grounding electrode present shall be bonded together. Doesn't say that it must be used or must be present as an electrode. On an old work situation you have no way to confirm that the pipe is in continuous contact for 10ft without excavating to know it meets the criteria not likely.
250.52(A) Electrodes Permitted for Grounding
250.52(A)(1) Metal underground Water Pipe. (Lays out criteria needed to be met to qualify as a grounding electrode NOT that it "shall be" and evidenced by the last two words in section. "If installed")
250.53(D) states "If used as a grounding electrode,.... it shall meet the requirements of 250.53(D)(1) and (D)(2).)
I don't see the criteria as requiring the water line to be a grounding electrode only that it must be bonded together with all other grounding electrodes. I think for the very reasoning that confirmation of eligibility without excavation to expose the pipe. New installation could be different.

Just to clarify I'll ask again, where in the NEC does it say street side of the water main?

250.53(D)(1) Continuity of grounding path ...... shall not rely on water meter or filtering devices or similar equipment. Thus anything that would or could break the continuity of the grounding path by removal or high impedance connections like a water meter could be interpreted as requiring the connection take place on the Street side of water main (or where it exits the structure). But a means of bonding jumper bypassing meter or other nonconductive or potentially high impedance connections needed to meeting bonding requirements.

 

[Doc13067]

I had my own question about this. I’ve always thought the ground rods were doing the “grounding” and the reason for running the wire to the pipe was “bonding“ so that the pipes are at the same potential as the rods and lightning will not travel through the dirt and up into the house and through the pipes.

In a situation with a main panel and a sub panel, is it ok to run a wire from the sub panel ground bus because it makes sense geographically (in cases where sub panel is closer to water pipe) or must the pipe be connected to the main panel where the neutral/ground bond occurs?

 

[LarryFine]

250.50 Grounding Electrode System. All grounding electrodes
as described in 250.52(A)(1) through (A)(7) that are
present at each building or structure served shall be bonded
together to form the grounding electrode system.

Doesn't seem like its use as an electrode is an option to me.