I spent the day with Mark Ode (along with 170 other guys). I caught him on a break, mostly asking about the turned up rebar Ufer deal. (He was OK with it)
Then I got him with the "can a GEC be green"?
He said of course it can. I said prove it.
He was still thumbing the book an the next break. I bet he will remember me ;-)

Greg- I don't find where the color is called out for the GEC but if I were asked by a contractor what color for the GEC my answer would probably be "bare or green". I would be hard pressed to write a violation for them using a red or orange wire. Since it is a grounding wire albeit a GEC it seems practical to use green or bare. Most electricians and other electrically inclined persons recognize green as a grounding conductor. Notice I said "most"

Any color or bare is allowed.
I made a proposal to the Code that at least in panels and switchboards it had to be identified with green or bare.
Rejected.
Seeing a black or red wire on a ground / neutral bar makes most electricians pause.
Oh well.

We plan on tackeling the rebar question next week. Any helpful information ?
Alan--

Start with 310.12
310.12(B) directs us to 250.119 for _equipment grounding conductors_. 250.119 repeats: 'Identification of Equipment Grounding Conductors'
The definition section distinguishes between Grounding Conductors and Grounding Conductors, Equipment. So 250.119 clearly does not apply to grounding conductors in general, but only to the specific subclass of _Equipment_ grounding conductors.

310.12(A) directs us to 200.6 for _grounded conductors_.
200.6 essentially specifies the use of white or grey for grounded conductors, possibly by marking for sizes larger than 6AWG
The definition section says that a grounded conductor is 'A system or circuit conductor that is intentionally grounded.'

The GEC is not an EGC. The GEC is not a circuit conductor. But the GEC is a conductor, and part of the electrical system. Therefor the GEC is a grounded conductor and thus governed by 200.6, and must be bare have a _white_ (or one of the other 200.6 variations) covering.

*grin*

-Jon

[This message has been edited by winnie (edited 01-29-2006).]

Nice "code loop", and interesting interpretation, Jon.
I would equate "grounded" conductors with neutrals, and/or grounded phase conductors which are intended to carry current(if need be)under normal operating conditions.
I never considered the GEC as a "grounded conductor" although it is a conductor and it is grounded.
BTW,
I usually use stranded black.

Redsy,

I quite agree with you. I have always understood 'grounded conductor' to mean a conductor that is _intended_ to carry current, as opposed to the 'grounding conductors' which should _not_ carry current in a properly functioning system. The above interpretation is what I get when I read the literal wording in the code.

This does lead to a logical conflict, since an equipment grounding conductor is also a 'grounded conductor', and therefore required to be white and green at the same time.

How about another funny: if you don't buy that the GEC is a grounded conductor, and by definition the GEC is also not an EGC, then you get to 'the GEC may be any color'. However, based upon 310.12(C) if you use a particular color for the GEC, then you can't use that color for an ungrounded conductor. So your use of the black covering for a GEC means you can't use it as a phase conductor

-Jon

Jon,
I have always rested on Article 200, which although titled "Use and Identification of Grounded Conductors", does not address conductors used for grounding purposes, and therefore would not consider conductors used for connecting Grounded Conductors to ground as grounded conductors, although these indeed are conductors which are connected to ground.

If you followed that, try this...

I can not consider that which is, without considering that by which, which is, is!

As far as 310.12(C), (grounded AND grounding conductors)good call!

Looks like we're back to green or bare for the GEC??

So if we have a bare Grounded or Ungrounded conductor we are stuck with Green for our GEC???

[This message has been edited by George Little (edited 01-29-2006).]

George, If we have bare Ungrounded, we are "stuck" alright.

But you knew that.

If I follow the code loop I end up with white or bare as logical choices. When you hang your amp probe on a GEC it will usually be carrying some of the unbalanced load.
It can be seen as an extension of the grounded conductor from the utility in a ring circuit that ends up being a parallel path back to the X0 via the earth or the water system.
It is hard to get over the idea that "grounding" conductors are not green but this is really a "grounded" conductor.

Alan, the only thing we really figured out on the rebar issue was that nobody could find a rebar listed acorn. There are plenty of 2 part clamps that are rebar rated.
As long as the rebar is not in a corrosive location and it remains accessible I really do not see the problem with this type of connection

Greg- Galvan makes an "acorn" clamp listed for rebar, direct burial in concrete or earth.

Thanks George. I was sure someone showed me one but I couldn't track it down.

oops.. let me try again

[This message has been edited by eprice (edited 01-31-2006).]

I doesn't work that way. If the NEC doesn't say you can't do something, then you can do it. It is your responsibility to prove that he can't do it.


No. I'm in the camp that consideres a GEC to a grounding conductor, not a grounded conductor. But, it is not an equipment grounding conductor. Therefore, there is no code section that requires it to be any particular color. It can not be white according to section 200.7. It can not be a color that would cause confusion with an ungrounded conductor per 310.12.

Try this one. Those of you who would consider the GEC to be a grounded conductor can not install a grounded electrical system. According to definition, a grounded conductor is a system or circuit conductor. The GEC is not a circuit conductor, therefore it must be a "grounded system conductor". 200.6 requires it to be marked with white or gray since it is a grounded conductor. 200.7 prohibits it from being marked by any of those means since it is not a "grounded circuit conductor". Therefore, it can not be installed

Why isn't it a "circuit conductor"? It will certainly be carrying some of the unbalanced current back to the transformer if it has any contact with the earth at all.

Well, I got that from winnie's premis arguing that it is a grounded conductor. But, if it is a circuit conductor, then how does it comply with 300.3(B)? or (A) for tht matter?

Nobody really likes to admit how much circuit current the GEC really does carry, particularly in a place where ground electrodes work well.
It is certainly carrying some unbalanced current.

I agree

BE nice here..

Do all GEC's normally carry current?

I am having a hard time visualizing how a GEC off a SDS 480x208 in a plant would carry current.

Help?

Dnk...

My understanding is that GECs are not _intended_ to carry current. This is the reason for all of the requirements about a _single_ bond between the _intentional current carrying conductors_ and the GEC.

However the _reality_ is that there are multiple bonds all the time. The common example is in residential service, where multiple residences will all share a single transformer, and _each_ residence will have its own grounding electrode, its own GEC, and its own ground to neutral bond at its own main disconnect. In these circumstances, you can expect to have at least some, and perhaps considerable, current on the GEC. Especially when the grounding electrode is the water service pipe, and the common underground piping system is itself metal. My 'hear-say' understanding is that smart plumbers place a jumper cable across water pipes prior to cutting them.

Also, even in a 'perfect' system where the SDS has a single ground bond with no galvanic parallel path, you will have some slight current on the GEC because of capacitive coupling between the system (and loads) and earth. The capacitive coupling of the various phases will tend to balance out, but any asymmetry in the system leads to just a bit of capacitive coupled current on the GEC.

-Jon

Greg,

Getting back to the rebar. You said "accessible", Is it really? Isn't it inside of the concrete?

Ufers around here are stubbed up rebar in a block core with a mud ring and plate over it. It does remain accessible.

Brian Holland, an inspector in North Port Fl came up with these rebar rated acorns

Brian
There are currently only (2) “acorn” style clamps listed for use with REBAR:

Erico (Eritech): Model # CP58 - #4 rebar

ILSCO: Models # GRC-38, GRC-48, GRC-68 - #3, 4, and 5 rebar