Is anyone aware of a jurisdiction where it is NOT common practice to use an underground metal water piping system (where present) as part of the grounding electrode system for a residence and rely soley on a driven rod? Likewise, any jurisdictions where the grounding electrode system is NOT bonded to the interior metal water piping system (where present)?
If so...WHY?

The 2002 code makes it clear that the cold water should be at a minimum be bonded and if 10' of metal in the ground shall be used as a grounding electrode.

250.50 requires that if available each item in 250.52(A)(1)-(6) shall be bonded together. Metal underground pipe is item 250.52(A)(1).

250.104 (A) requires bonding of metal water piping.

So any jurisdiction not using the cold water is violating the NEC. The workbook notes in 250.52(A)(1) that there has always been uncertainty about using the cold water, but that NIST has monitored the issue and found minimal problems.

Just a P.S. folks, I know that the NEC requirements are...what I am wondering about is local practices that may vary. Thanks!

Yes I know you know, I was just stating what the people would be violating if they didnt bond the metal water. Its very clear from the NEC to do so, so I don't think anywhere would say you shouldnt. Everywhere in SoCal you have to bond the cold water.

Ther are places that forbid this. Where? I don't know. But I am 100% sure that this is true.

I have to go with Scott here, I have read on these forums before that certain water companies forbid using the water supply as a grounding electrode.

Where?

Sorry I do not remember.

Bob

Bonding of the metal water pipe is mandatory in the code book, both well water or municipal.

Using it as a ground electrode is not mandatory, code simply states it can be used as an electrode, but must be supplemented if used as an electrode.

At least that is the way I read it..

Dnk......

Dnk


As far as the NEC is concerned if a metal water pipe exists on the premises that fits the criteria of 250.52(A)(1) it must be used.

These areas that do not use it are either ignoring or amending the NEC.

Iwire,

I am aware of what is states.
It is the wording that throws you off.
250.52 States that a water pipe is PERMISABLE, does not state it is mandatory.

I assume, they do not mean you have to have one or use one, but it is permissable to use it as a ground electrode, if it is supplemented by another ground electrode.

250.50 tells us it is mandatory to use each of the items in 250.52 if they are avialable.

It is not a choice.

No it doesn't.
250.50 states if they are available, the must be bonded.
250.50 doesn't state a underground water pipe must be used as a ground electrode.

Better still, 2005 NEC 250.50 says "if present", they must be used.

Sorry, but I think you are worng. I am with Bob on this one.

I haven't got the 2005 code book, maybe they reworded it.

I am going by the wording of the 2002 book.

It's not who's right or wrong, it's just the wording that could throw you off.

It's like Emt. It is PERMISSABLE to use it as a ground, You don't have to, you are allowed to pull and EG in the EMT. But you could use it.

Does the 2005 book state the water pipe has to be used as an electrode or does it still state it has to be bonded?


Dnk.......

Dnk you are really surprising me on this one, I thought this was a clear one.


Yes 250.50 states it must be bonded.

Bonded into the grounding electrode system.

Then 250.24(C) requires this grounding electrode system to be connected to the grounded conductor by means of a grounding electrode conductor.

If a water pipe is present that meets the criteria of 250.52(A)(1) it must be used along with any other present electrodes as a grounding electrode.

Bob

It does say bonded...."bonded together to form the grounding electrode system.

I allready posted about Bufflao Grove IL does not allow grounding rods. Why? They don't know it's just allways been that way sence the last electrical inspector.

Tom

It doesn't say "shall be permitted to be bonded", it says it "shall be bonded." Period. By the NEC, all the available grounding electrodes shall be used.

See 90.5 for a refresher on mandatory versus permissive language.

I think the confusion comes from the change in how we look at the water pipe.

In the old days, the water pipe was seen as the "grounding electrode," the point where lost electricity returned to earth.

That is no longer true. Today, the water pipe is nothing more than another piece of metal, that we connect to the ground wire network to "drain" it of any "lost" electricity, return that electricity to the panel, and let it return to earth through the ground rod.

In very simple terms, this is the difference between "grounding" and "bonding".

We used to "ground" through the pipe.

We now "bond" the pipe.

Again, metal water piping must be bonded in all cases, and may double as a grounding electrode if certain circumstances permit.

If you blind yourself to everything else and read this: "250.53(2) Supplemental Electrode Required. A metal underground water pipe shall be supplemented by an additional electrode of a type specified in 250.52(A)(2) through (A)(7)."

It might sound as thought an underground water pipe were the MAIN GROUND electrode, all others were extra.

As to the original question, I can not think of anywhere that would not want it bonded, if not part of the electrode system.

And only time I think it would not be considered part of the electrode system is if it had a water meter less than 10' away.

As far as local practice:
Water GEC is sized for service - always!
(2) rods as supplimentary electrodes
Bonding:
Load side of gas meter bonded to service or electrode system.
And hot water at the point nearest origin and continuous to the electrode system cold water at nearest point. (Like at the water heater.) Used to hit the gas there too, until a few years back.

And yep, different places require different things as far as this goes.

Saw some commentary in the code about this:
Maybe they are still arguing about it somewhere?

[This message has been edited by e57 (edited 06-01-2005).]

A similar change occurred here in the U.K. as well. Up until the 1950s it was common for the water line to be used as the sole method of grounding. Now we use a separate electrode, but the water pipe must be bonded to it.

e57 - in your quote:
It is mentioned that DC can cause minumal problems. Does the article mention anything about AC? For the record, I support using the qualifying water line as an electrode or bonding it if it's not qualified as an electrode. It does sound like the code panel don't trust the water pipe though because it's is in need of a suppliment. Other electrodes are probable more reliable.

The reason I threw this out there is because I lost a dinner to it.

We all know the applications of bonding the water pipes, however, back to my original post:
Nowhere in the NEC does it state you have to use a water pipe as a ground electrode.
I threw every argument you guys have tossed out there, and all it states is it SHALL be bonded to the Grounding Electrode System.

The whole PERMISSABLE thing cost me dinner.

Dnk.....

Dnk: I don't know how you are not getting this. 250.50 seems very clear to me.

dnk make me understand this.

Do you agree 250.50 requires us to bond the water pipe to any other present grounding electrodes forming a grounding electrode system?

Do you agree that theses electrodes that are bonded together into a grounding electrode system are required to be connected to the service grounded conductor?

If your answer is yes to both of these then how can you say the water pipe is not required to be used as a grounding electrode?

Now lets look at this from another direction.

250.50 references all electrode types.

It seems by your interpretation that none of the electrodes are required to be used.

Bob

You have to be careful when you actually apply logic, otherwise your inground concrete pool is the biggest ground electrode in the system. Just don't say that out loud. ;-)

I know it will be the main grounding path when lightning hits my screen cage. That's why there is so much 8ga wire there and so many bonding lugs on the cage.

Sure is hard to see which way those pesky electrons are going! :-)

Gee, I miss looking at this for a day and the replies go wild! Little flame icon and all...

Let me ask my original question again... Is anyone aware of a jurisdiction or part of the US where this is NOT done as regular practice. If so, why not?

Thanks.

jes the areas that I have heard about not allowing the water pipe as a GEC do so for the safety of the water department workers.

A dielectric fitting is placed in the pipe and you can bond the water pipes on the house side of the dielectric fitting.

No electrical connection is allowed on the street side of the dielectric fitting.

[This message has been edited by iwire (edited 06-04-2005).]

I guess it would be difficult to require all water pipes to be used as electrodes when a good percentage don't qualify as electrodes.

You could be required to prove that there is a continuous 10' of pipe in contact with the earth, which isn't easy to do in existing work.

Bob, Just because you bond something to a ground electrode system, that doesn't make that item a ground electrode, does it?

Because 250.50 directs us to bond the water pipe, this doesn't make that water pipe a ground electrode.

Dnk....

DNK
250.50 directs us to bond TOGETHER all of the electrodes that are present(05).

250.52(A) Electrodes Permitted for Grounding

This is where I think your confusion lies.
.52 shows us the electrodes that are permitted to be used for electrode, .50 tells us the ones that are present are required to be bonded together to form the grounding electrode system, cold water being one of them.

If the cold water is used for the electrode, it is required to be supplemented. The reason for this is not because it is not a good electrode (on the contrary), but because so many repairs today eliminate the copper pipe with plastic, and the plumbers making these repairs are not worried about our grounding electrode systems.

Believe me when I tell you, I am not confused over this.
I am just looking for the answer that will get me my Burger Dong chicken sandwich back.

But I still haven't got the answer.


Dnk....

I think you have...you just haven't accepted it yet

Dnk, 250.50 addresses grounding electrodes.

250.104 addresses bonding of a water pipe, probably in the event that it is not eligible as a grounding electrode.

You are confusing your concepts.

Open your book!

250.52(A)(1) defines the grounding electrode. It doesn't state whether or not to use it at all. That is accomplished through 250.50.

Are you talking about 250.52(A)'s title?

It's meaningless when taken in context of 250.50's requirement.


The water pipe's inclusion in 250.52(A) makes it a grounding electrode, not a "bonding electrode", as if there is such a thing.

The title of 250.52 is "Electrodes Permitted for Grounding." This section's whole purpose for being is to create a Grounding Electrode System. How can you single out an electrode and say it's not really performing the same function as it's counterparts in (2) through (7)?

[This message has been edited by The_Judge (edited 06-04-2005).]

Open your book?
What kind of comment is that?

Let's look at the Code on cd with the commentary for a second.

""Section 250.53(D)(2) specifically requires that rod, pipe, or plate electrodes used to supplement metal water piping be installed in accordance with 250.56. This requirement clarifies that the supplemental electrode system must be installed as if it were the sole grounding electrode for the system. If 25 ohms or less of earth resistance cannot be achieved with one rod, pipe, or plate, another electrode (other than the metal piping that is being supplemented) must be provided. One of the permitted methods of bonding a supplemental grounding electrode conductor to the primary electrode system is to connect it to the service enclosure.
The requirement to supplement the metal water pipe is based on the practice of using a plastic pipe for replacement when the original metal water pipe fails. This type of replacement leaves the system without a grounding electrode unless a supplementary electrode is provided. """""

If we are required to supplement the water pipe with aditional electrodes,and these supplemental electrodes are required to be the sole grounding electrodes for the service, then the water pipe must not be too reliable of a source. This would mean the water pipe does not cut it as a grounding electrode.

Or am I still reading this wrong?

Dnk......

In my opinion yes, you are reading it wrong.

250.50 applies to the list in 250.52 equally.

I have two questions.

1) How did you single out the water pipe?

2) In your opinion are there any items in 250.52 that are required to be used as grounding electrodes or is it just a water pipe that is excluded?

I'm sorry, that was over the line. I apologize, no offense intended.

I just can't understand how you can pick one item out of a list entitled "Electrodes Permitted for Grounding" and decide it's not really a grounding electrode, but a ground rod (which is no unreliable that it is all but required to install two of them when used) is.

Again, sorry.

I have an idea: Lets each of us kick in and buy Dnkldorf a dinner so he'll lighten up. Or better yet- Lets all of us get our black highlighter and high light the text following 250.52(A)(1).

I haven't seen a metal water pipe installed in over 20 years. Everyone just "pastes PVC pipe" here.

The commercial jobs around here still have metal water supplies, I don't know about new dwelling units.

My house (circa 1925) has a lead water main, we don't drink or cook with the water.

But you still bathe and clean your dishes with it iwire? Might be worth the money to replace it.

I am not worried, we had the lead levels tested and it is nothing to worry about we could drink it.

We did have a scare with one of my kids when she had a lead screening.

It came out dangerously high, second test and all since have proved the 'high' test was thankfully in error.

Here's an important paper made available to Massachusetts residents concerning the lead water pipe problem:
http://www.nber.org/papers/W9549