Ground Conductor Splicing

[George Stolz]

Re: Ground Conductor Splicing

Bob, I had a hum-dinger of a response written up, and then She Who Must Be Obeyed booted me off and lost it.

Edit on last cut: This post wound up twice as long, sorry.

Originally posted by iwire:
George the wording describing a water pipe grounding electrode and a concrete encased electrode are quite different.

Can you point to the differences that you think are the most relevant?

A water pipe grounding electrode can and does exist outside of the ground up to 5'.

Let's look at it.

Interior metal water piping located more than 1.52 m (5 ft) from the point of entrance to the building shall not be used as a part of the grounding electrode system...

1. It does not say that the electrode is 5' long once it's inside.

2. It says that you cannot use beyond 5' as part of the GES.

There's a subtle difference between these two concepts that is pivotal to our discussion. One, although the interior does not qualify as a grounding electrode, they assume we will make our connection to the electrode from the interior. This is profound. This makes my case. This sets a precedent that there is no specific permission to use portions of this particular object, that are connected to but not qualifying as "electrode", but it is inherently allowed.

It is inherently allowed because they have to write language to restrict it. Working backward, if this sentence did not exist, then we could do exactly what it's prohibiting us from. Otherwise it's existence would be pointless.

The presence of the "shall not be used" comment indicates that if this sentence weren't there, I could run my GEC to the toilet next to the service. I could connect anywhere in the structure, so long as the pipe were "continuous to the points of connection of the grounding electrode conductor and the bonding conductors."

The 5' comment is not in the description of the electrode. It's a peripheral rule related to the pipe, but it's not a descriptor of the pipe itself.

Read the sections carefully using "Charlie's Rules".

Forget what you have done or what you think they should mean.

You took the words right out of my mouth.

As electricians, a water pipe electrode is second nature to us, because it's easy, and it's always done a certain way. You never install your own, it usually looks the same, we never have to give it much thought.

Then again, for many, it's also natural to look to the water pipe as a "primary" grounding electrode. It's natural for someone to assume they must install a "secondary" ground rod for a Ufer. They did it for a water pipe. People operating on their daily experiences without research will rely on their experience to come to their own conclusions. You have taught me and dispelled some of these myths for me.

It's natural to look at a piece of #4 and call it a "conductor." It's not natural to look at that same item protruding from a concrete wall and call it an "electrode." If it were a chunk of rebar, it'd be an easier pill to swallow. As it is, it just doesn't feel right.

Recently I posted a series of methods that a local inspection agency listed as being acceptable. I just searched high and low for it, but it appears the thread (or just my post) was deleted. It was long and I'm not going to re-type it. I don't believe that I said anything inflammatory, and I don't remember the tone being tense when I left the thread, so I'm a little ticked it was deleted.

For the "preconceptions" portion of our discussion, it was a fine display of how a chunk of rebar sticking out is more acceptable to our collective tastes than the #4 version of what the NEC considers to be the exact same thing.

 

[iwire]

Re: Ground Conductor Splicing

Originally posted by georgestolz:

Originally posted by iwire:
George the wording describing a water pipe grounding electrode and a concrete encased electrode are quite different.

Can you point to the differences that you think are the most relevant?

I have but I will again.

250.52(A) (1) Metal Underground Water Pipe. A metal under-ground water pipe in direct contact with the earth for 3.0 m (10 ft) or more (including any metal well casing effectively bonded to the pipe) and electrically continuous (or made electrically continuous by bonding around insulating joints or insulating pipe) to the points of connection of the grounding electrode conductor and the bonding conductors.

That tells us the water pipe grounding electrode is both in direct contact with the earth and electrically continuous to the point of connection.

250.52(A)(3) Concrete-Encased Electrode.

An electrode encased by at least 50 mm (2 in.) of concrete, located within and near the bottom of a concrete foundation or footing that is in direct contact with the earth, consisting of at least 6.0 m (20 ft) of one or more bare or zinc galvanized or other electrically conductive coated steel reinforcing bars or rods of not less than 13 mm (? in.) in diameter, or consisting of at least 6.0 m (20 ft) of bare copper conductor not smaller than 4 AWG. Reinforcing bars shall be permitted to be bonded together by the usual steel tie wires or other effective means.

Do you see anything in that that says it continues outside the concrete encasement until it reaches the point of attachment?

No, all you see is that a Concrete-Encased Electrode is in fact encased in concrete.

Here is an image that may help



Bob

[ December 09, 2005, 04:48 AM: Message edited by: iwire ]

 

[iwire]

Re: Ground Conductor Splicing

Originally posted by georgestolz:
Recently I posted a series of methods that a local inspection agency listed as being acceptable. I just searched high and low for it, but it appears the thread (or just my post) was deleted.[/i]

As far as this, I have much trouble with the search feature here.

I am willing to bet you post is still there but the search engine is missing it.

 

[George Stolz]

Re: Ground Conductor Splicing

Originally posted by iwire:

250.52(A) (1) Metal Underground Water Pipe. A metal under-ground water pipe in direct contact with the earth for 3.0 m (10 ft) or more (including any metal well casing effectively bonded to the pipe) and electrically continuous (or made electrically continuous by bonding around insulating joints or insulating pipe) to the points of connection of the grounding electrode conductor and the bonding conductors.

That tells us the water pipe grounding electrode is both in direct contact with the earth and electrically continuous to the point of connection.

The "and" that you bolded means it must be underground and continuous. As in, it must be continuous underground. How do you read that to say that the electrode becomes continuously an electrode outside of dirt to the connection? We are to make things continuous - it's not telling us that the electrode becomes continuous by virtue of not having a GEC connected to it for 3 feet.

It's telling us to ensure that we have ten continuous feet of metal water pipe to the connection. It doesn't say a word in the first sentence to indicate the connection is to be anywhere but underground.

250.52(A)(3)

Do you see anything in that that says it continues outside the concrete encasement until it reaches the point of attachment?

No, but I don't see a permissive statement to that effect in (A)(1) either. The second sentence in (A)(1) restricts an area not covered by the definition of the electrode in the first sentence.

Any section of rebar or wire not encased by a minimum of 2" of concrete is not per the NEC description a concrete encased electrode.

Any section of metal water pipe that is not continous and underground is not a grounding electrode. But they expect us to connect to the electrode outside the defined area, don't they?

 

[iwire]

Re: Ground Conductor Splicing

I am done believe what you want.

I do not buy any of your argument.

 

[pierre]

Re: Ground Conductor Splicing

George
You are making this topic much more difficult than need be. You are dissecting the Code like a Shakespere novel.

The cold water electrode is permitted to be terminated to no more than 5 ft after the point of entrance. The cold water pipe is the electrode, the conductor to the 1st point of disconnect is the GEC. The NEC gives permission for this electrode to actually extend to the inside of the building.

The concrete encased electrode has to be encased by at least 2 inches of concrete, and the GEC actually will itself have 2 inches of concrete for a bit, as it terminated to the electrode (the electrode is the copper conductor or rebar).
There is no permission by the NEC for any part of this electrode to extend past the concrete.

 

[George Stolz]

Re: Ground Conductor Splicing

Originally posted by pierre:
You are making this topic much more difficult than need be. You are dissecting the Code like a Shakespere novel.

I have a tendency to dissect things. Sometimes, it leads somewhere, sometimes I'm just being stupid. Persuing it helps me to achieve a better understanding of the code.

Bob, I'm sorry if I've been like arguing with a brick wall. I'm just not seeing it. I mean, I know where you're coming from, but I'm not convinced it says what we expect to see.

Does anyone have the 250.52(A)(1) text prior to the existing text, before the 5' rule for the water pipe electrode came into being? I am very curious as to what that said.

Just going on gut instinct, I'd wager 50? that it mentioned nothing about terminating indoors, and that it was assumed to be permissible by virtue of it's ongoing practice in the field.

I believe this entire discussion has great relevance, because it's fundamental. It affects what advice we give to the original poster of this thread, and threads in the future. It affects our options for our day-to-day operations. Besides, it's just good to know.

Right now it is common practice around here to stub rebar out of the concrete and attach to that. If it's wrong, I'd like to know for certain it is wrong; because it's one of three methods recommended by a local (tight) inspection agency to comply with 250.50. It's also recommended in other jurisdictions.

That does not jive with the majority opinion here.

I would like to feel 100% sure about something, even if I'm shown to be woefully stupid yet again.

 

[mvannevel]

Re: Ground Conductor Splicing

Originally posted by georgestolz:
Is the #4 CU the grounding electrode, or the Grounding Electrode Conductor to the electrode?

I see exactly what you are saying here George. And I also see your point about leaving the re-bar stubbed out of the concrete for connection to the GEC. That's the common method around here when the pour will be made before the electrician gets there to make the connection (that's when a Ufer is used. We're still on the '02 Code here so they're not used that often).

This whole business of being required to use Ufer grounds is going to take some getting used to. While they were an option, no provisions had to be made for them. You either got there before the pour and connected to the re-bar (or installed the #4) or you didn't. Now it's a different story. Electricians and inspectors are going to need to come to a consensus on this unless (or until) the code becomes more specific.

I see the concrete encased electrode stubbed out of the concrete as being analogous to the metal water piping extending into the building. Just as long as you have 20' of it encased in 2" of concrete, where you attach to it doesn't seem to be addressed. A metal underground water pipe becomes a grounding electrode when you have 10' or more in direct contact with the earth. In both instances, we address bonding to make the electrodes continuous. 250.68(A) requires the GEC connection to a grounding electrode to be accessible but since the metal underground water pipe is buried, the exception would allow us to make the connection to that pipe underground. We wouldn't normally do that, but we could if we wanted to go to the trouble. It's just "normal" practice to make the connection inside. And when we do that, it's required to be within 5' of where it enters.

The requirement for making the GEC connection to the water piping within 5' of where it enters the building has everything to do with the fact that metal piping can be isolated by insulating joints or installation of nonmetallic piping and nothing to do with the necessity to make the connection close to where the piping is in direct contact with the earth. Obviously, (I've never seen nonmetallic re-bar) no such consideration is necessary with re-bar.

So, for the original posters question, it does matter whether the #4 is being used as the grounding electrode or is connecting to the grounding electrode.

All that having been said, if it were me, I'd use an irreversible splicing method no matter what. Why take a chance?

 

[George Stolz]

Re: Ground Conductor Splicing

Why take a chance?

Expense and resources.

 

[iwire]

Re: Ground Conductor Splicing

Originally posted by georgestolz:
Bob, I'm sorry if I've been like arguing with a brick wall.

Thanks, as that was the root of my frustration in this thread.

Originally posted by georgestolz:
Does anyone have the 250.52(A)(1) text prior to the existing text, before the 5' rule for the water pipe electrode came into being?

IMO All that is relevant to this disagreement we have is contained in 250.52(A)(3).

Originally posted by georgestolz:
Right now it is common practice around here to stub rebar out of the concrete and attach to that. If it's wrong, I'd like to know for certain it is wrong;

I have never said that pratice is wrong.

What I have said is that section of rebar that is not encased in 2" of concrete is not a Concrete encased electrode that section is a bonding jumper or a GEC. (Yeah that's a problem in itself)

Originally posted by georgestolz:
I would like to feel 100% sure about something,

100% sure about an NEC section?....come on....now you want miracles!

If you want to keep going on this lets keep it confined to one section at a time.

250.52(A)(3) Concrete-Encased Electrode.

What does the title of the section tell us?

Main Entry: en?case
Pronunciation: in-'kAs, en-
Function: transitive verb
: to enclose in or as if in a case

Main Entry: en?close
Pronunciation: in-'klOz, en-
Function: transitive verb
(1) : to close in : SURROUND <enclose a porch with glass>

Now does the section go on to tell us the electrode is not encased, enclosed or surrounded?

 

[George Stolz]

Re: Ground Conductor Splicing

Originally posted by iwire:

Originally posted by georgestolz:
Does anyone have the 250.52(A)(1) text prior to the existing text, before the 5' rule for the water pipe electrode came into being?

IMO All that is relevant to this disagreement we have is contained in 250.52(A)(3).

Humor me.

What's good for the goose is good for the gander. If a water pipe has always been permitted to be connected outside of the defined zone, then it sets a precedent that should be allowable for the other electrodes.

 

[iwire]

Re: Ground Conductor Splicing

Originally posted by georgestolz:
If a water pipe has always been permitted to be connected outside of the defined zone, then it sets a precedent that should be allowable for the other electrodes.

[ December 10, 2005, 09:47 AM: Message edited by: iwire ]

 

[George Stolz]

Re: Ground Conductor Splicing

Originally posted by iwire:
It in no way 'sets a precedent'.

Two entirely different items.

Bob, they're located in the same section, they're doing the same job, and they're similar in construction.

A water pipe is not specifically required to be encased in dirt, a concrete encased electrode is specifically required to be...get this...encased in concreate...go figure.

 

[iwire]

Re: Ground Conductor Splicing

Originally posted by georgestolz:
Bob, they're located in the same section, they're doing the same job, and they're similar in construction.

Yes they are in the same section, they do the same job, they are not of similar construction.

All the tap rules are in the same section, that does not mean they are interchangeable?

OK I did overlook the underground part but is still not required to be encased or surrounded by dirt.

Again I am frustrated with your lack of seeing the obvious.

Maybe I will come back to this, hopefully others will join in.

Bob

[ December 10, 2005, 10:31 AM: Message edited by: iwire ]

 

[George Stolz]

Re: Ground Conductor Splicing

Originally posted by iwire:
Again I am frustrated with your lack of seeing the obvious.

 

[iwire]

Re: Ground Conductor Splicing

George I am not going to agree to disagree.

I feel I am correct and you are not.

 

[iwire]

Re: Ground Conductor Splicing

Originally posted by georgestolz:
Here's something obvious: If (A)(3) had the sentence "rebar protruding farther than 5' into the structure shall not be used for the interconnection of electrodes" added at the end, these two sub-sections would be virtually identical.

And if a frog had wings it could fly. :roll:

 

[George Stolz]

Re: Ground Conductor Splicing

I am pretty good with computers, so I am going to draw a analogy from my experience with computers to try to explain where I am coming from. Step out on to my rickety mental bridge and take in the view, I can guarantee it's worthwhile.

Computers are absolutely logical. If you type something into code that is not logical, or unrelated, you get an error message, or the computer waits for the end of time for some input to keep going, or the unrelated piece of code gets ignored. It doesn't come to conclusions, it starts at the beginning, goes through the events in a row, and if you've done your job well, you get the desired results at the end.

If a computer were to be programmed to start at the beginning of the section, and work through it, it would need guidelines for how to interpret that information and then how to proceed.

The simplified guidelines (we agree on) would include the following:
</font>

• <font size="2" face="Verdana, Helvetica, sans-serif">One: This code is a permissive document.</font>
• <font size="2" face="Verdana, Helvetica, sans-serif">Two: Mandatory and Permissive statements are defined in 90.5.</font>

<font size="2" face="Verdana, Helvetica, sans-serif">
To that, we'll add Bob's rule:
</font>

• <font size="2" face="Verdana, Helvetica, sans-serif">Three: The connection to an electrode must be to the defined portion of the electrode.</font>

<font size="2" face="Verdana, Helvetica, sans-serif">
When we apply these rules to the Ufer, everything comes out the way it's expected to. The GEC must enter the concrete to connect to the Ufer.

When we turn this mechanism against the water pipe, what happens?

The water pipe connection suddenly must be underground. What happened? The defined area of the electrode is underground. So, the connection can't be anywhere else.

But, you say, George, you're ignoring the second sentence. And you'd be right. You know why? Because that's exactly what the computer would do. We draw a connection between the two sentences, and make assumptions. The computer can't do that. It can only follow it's guidelines. The defined area of a water pipe electrode is underground, so applying the three guidelines, we end up with it underground.

Interior metal water piping located more than 1.52 m (5 ft) from the point of entrance to the building shall not be used as a part of the grounding electrode system or as a conductor to interconnect electrodes that are part of the grounding electrode system.

If it is interior, then it is not in the defined underground area of the electrode. So the connection cannot be there, when applying the guidelines with Bob's rule attached.

When we remove Bob's rule, then the scenery changes dramatically. The second sentence of the water-pipe code falls into place, and we can make our connection inside.

We as people with preconceptions and experiences and expectations see what we want to see. And compounding the issue, people wrote this section. People are doing the reading, and the writing. People can create patterns where there are none. Stars that are billions of miles apart are turned into constellations. Satan can be heard telling you to murder Snoopy and tickle your dog when you turn a record backwards.

We see something that doesn't exist when we look at (A)(1). Permission to connect to the interior water piping.

When the code says "Interior metal water piping located more than 5 ft from the point of entrance to the building shall not be used as a part of the grounding electrode system" we see permission. What is the designed phrase for permission? Shall be permitted. What's mandatory? Shall or shall not.

If that sentence is not our permission, and all it's saying is that we shall not connect farther than 5 ft from the entry, where's the permission to connect in that interior 5 feet? No where.

We're permitted because we're not prohibited; it goes back to Guideline Number One.

 

[LarryFine]

Re: Ground Conductor Splicing

Just a quick jump-in of what may be the obvious here:

In order to qualify as a grounding electrode, the connection must be within 5 feet of the pipe's entrance, and the pipe must have at least 10 feet in the ground.

Even if the above requirements are not met, the pipe must still be bonded to the system ground. We're not prohibited from making this bond; it just doesn't qualify as an electrode.

 

[pierre]

Re: Ground Conductor Splicing

George and Bob
Take 3 deep breaths, stay away from this thread for a little and lets see....

Bob
I happen to agree with you 100% on this one... see we can agree

George
Regardless of what the code may have said prior to '93 we are reading and following the current codes. Yes they are in the same section, but Bob's analogy to 240.21(B) is very good for this thread.
To humor you though, I will post the '90 code section on this.


H. Grounding Electrode System

"250-81(a) Metal Underground Water Pipe.
a metal underground water pipe in direct contact with the earth for 10 feet or more (including any metal well casing effectively bonded to the pipe) and electrically continuous (or made electrically continuous by bonding around insulating joints or sections or insulating pipe) to the points of connection of the grounding electrode conductor and the bonding conductors. Continuity of the grounding path or the bonding connection to the interior piping shall not rely on water meters.

(the rest of the section specifies the supplemental electrode - not part of this thread, so I did not type it).


K. Grounding Conductor Connections

250-112. to Grounding Electrode.
... Where necessary to assure this for a metal piping system used as a grounding electrode, effective bonding shall be provided around insulated joints and sections and around any equipment that is likely to be disconnected for repairs or replacement. Bonding conductors shall be of sufficient length to permit removal of such equipment while retaining the integrity of the bond.
exception: An encased or buried connection to a concrete-encased, driven, or buried grounding electrode shall not be required to be accessible.

SIDE NOTE: It it is interesting how different this portion of the NEC is from '90, to now.


I think what needs to be done is not add information, just read what is there.


250.52(A)(1)
Mentions the cold water is permitted to be connected within 5 ft of where it enters the building.


250.52(A)(3)
Only mentions the electrode itself, encased in 2 inches of concrete - nothing about how it enters the building.

250.66(B) Connections to Concrete-Encased Electrodes.
This subsection does not mention any location.

With this comparison, the GEC needs to be connected to the Electrode - the concrete-encased electrode as per code is buried in 2 inches of concrete. (what local jurisdictions permit is another story)