transformer ground

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trock918

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the ground wire going from building steel to the transformer, can you use a simply romex conn. to enter the transformer or is there a new code were you have to use something else
 
The NM connector would have to be listed for the type and size of conductor passing through it, not very likely.

Welcome to the forum. :smile:
 
I don't know of any section that requires a connector on a GEC entering an enclosure.

If there is not such a requirement, the non-required connector can have an appropriate listing on it, or no listing at all.

If there is a requirement somewhere, we need to see what that section says.

It might be hard to get around 110.3(B) though. There is no wiggle room there. If it is listed, we have to use it in accordance with the listing.

That would be better written as "Equipment required to be listed or labled by this Code shall be installed and used in accordance with any instructions included in the listing or labling."

That way a galvanized rigid metal conduit length installed as a raceway would need to be installed per whatever instructions may exist, but if it was to be used as a driven pipe electrode per 250.52(A)(5)(a), that would be allowed to. Too bad, might have to use a non-listed pipe for that.

On the other hand, UL seems to allow at least one instance of using a "single conductor" cable with a fitting not recognized for the use in the White Book 2007:
NONMETALLIC-SHEATHED CABLE CONNECTORS (PXJV)
GENERAL
Connectors for use with nonmetallic-sheathed cable are also suitable for
use with multi-conductor underground feeder and branch circuit cable
where used in dry locations unless otherwise indicated on the carton.
Single Cable ? If single conductor Type UF cable is terminated with a
fitting not specifically recognized for use with single conductor cable, special care should be taken to assure it is properly secured and not subject
to change.
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How about 250.64 but really 250.64(F).

I want to say it elimates the choking effect, I hear this old timer talk about when he's around the Big Stuff;
"No, one can't just pop a bare GEC through a metal frame without using a bonding type bushing...", which 250.64 says. I guess he failed a inspection on that point alone a long time ago :)

I realize its a little different than the use of a nm conductor.

Grounding is not my strong point, I should get that MH book on that subject and it on Sale! :)

& welcome to the Forum !!!!
 
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Sorry to bump this thread but this is an important point that most electricians dont understand.
Cadpoint you are very close. The relevant article is 250.64(E). Basically, if the GEC passes through any ferrous metal, (enclosure, conduit, etc) the ferrous metal part must be "made electrically continuous". That means bonded to the GEC. (If its conduit it has to be bonded at both ends) The reason is inductance, or as you say the choking of current flow. Doesnt matter what kind of wire.
This is one of the most common code violations in the country.
 
ZZDoug said:
Sorry to bump this thread but this is an important point that most electricians dont understand.
Cadpoint you are very close. The relevant article is 250.64(E). Basically, if the GEC passes through any ferrous metal, (enclosure, conduit, etc) the ferrous metal part must be "made electrically continuous". That means bonded to the GEC. (If its conduit it has to be bonded at both ends) The reason is inductance, or as you say the choking of current flow. Doesnt matter what kind of wire.
This is one of the most common code violations in the country.
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When the GEC is bonded to the enclosure inside the enclosure itself there is no electrical or code reason to bond the GEC to the enclosure at the point where the GEC enters the enclosure. It is made electrically continuous when it is bonded to the terminal point inside the enclosure.
 
This reminds me of an IAEI meeting with either Jim Pauley (it was some time ago so I think it was Jim Pauley) or Alan Manche of Square D. This question came up and the response was, "why do you think we put the ?" KO in the bottom of a meter fitting?" It is for a #4 or smaller conductor to pass through to the ground rod. I believe the UL representative was Don Nisson who agreed. Right (I believe that the panel was right) or wrong, that was the end of the discussion from the panel. :)
 
charlie said:
This reminds me of an IAEI meeting with either Jim Pauley (it was some time ago so I think it was Jim Pauley) or Alan Manche of Square D. This question came up and the response was, "why do you think we put the ?" KO in the bottom of a meter fitting?" It is for a #4 or smaller conductor to pass through to the ground rod. I believe the UL representative was Don Nisson who agreed. Right (I believe that the panel was right) or wrong, that was the end of the discussion from the panel. :)
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Yes, and most resi load centers have a small ko for same thing. Thanks Don and Charlie!
 
HotConductor said:
I can't imagine an inspector failing an install over something like this. If this is what we've come to, that's sad.
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AMEN!, Brother. In this area:
If it's installed, great. If it's the correct size, fabulous
 
don_resqcapt19 said:
When the GEC is bonded to the enclosure inside the enclosure itself there is no electrical or code reason to bond the GEC to the enclosure at the point where the GEC enters the enclosure. It is made electrically continuous when it is bonded to the terminal point inside the enclosure.
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Don - I have always thought this was the case and have installed and passed inspections with this view...however.

Upon further reflection and reading 250.92(A) - "The non-current carrying metal parts of equipment indicated in 250.92(A)(1), (2), and (3) shall be effectively bonded together.

250.92(A)(3) - "Any metallic raceway or armor enclosing a grounding electrode conductor...."

Further, Exhibit 250.32 [2002 NEC Handbook....I'm at work and don't have my 2008 with me] shows an additional bonding bushing/jumper on the metal raceway at the service enclosure.

When I checked with my senior electrical inspector he concurs that the bonding jumper at the service equipment is a requirement.
 
don_resqcapt19 said:
When the GEC is bonded to the enclosure inside the enclosure itself there is no electrical or code reason to bond the GEC to the enclosure at the point where the GEC enters the enclosure
Click to expand...
This is true, 250.64(E) essentially says that. But thats assuming that the enclosure is indeed bonded correctly for this ....... its not always. The point is that it has to be "electrically continuous" with the GEC, not something else. My thinking is that if the enclosure isnt bonded directly to the point (ground bar etc) where the GEC is connected, or bonded to the GEC itself, then its not legal. So it depends on how its done.
 
dana1028 said:
Don - I have always thought this was the case and have installed and passed inspections with this view...however.

Upon further reflection and reading 250.92(A) - "The non-current carrying metal parts of equipment indicated in 250.92(A)(1), (2), and (3) shall be effectively bonded together.

250.92(A)(3) - "Any metallic raceway or armor enclosing a grounding electrode conductor...."

Further, Exhibit 250.32 [2002 NEC Handbook....I'm at work and don't have my 2008 with me] shows an additional bonding bushing/jumper on the metal raceway at the service enclosure.

When I checked with my senior electrical inspector he concurs that the bonding jumper at the service equipment is a requirement.
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Dana,
I don't see where those rules apply when the GEC is not in a raceway. I do not see the installation of a GEC directly through the enclosure wall as being the same as installing a GEC in a ferrous raceway that is connected to the enclosure.
However I have said that the ferrous raceway connection to the enclosure does not require any bonding other than the two locknuts. I see from the section that you have cited that I am wrong about that. Service bonding methods are required for the GEC raceway connection to the enclosure are required.
 
don_resqcapt19 said:
I see from the section that you have cited that I am wrong about that. Service bonding methods are required for the GEC raceway connection to the enclosure are required.
Click to expand...

Don what specific wording are you seeing that requires this? Are you saying that at the least a bonding locknut is required?
 
Rob,
I did that at work and was looking at the following in the 2005 code.
250.92 Services
(A) Bonding of Services The non–current-carrying metal parts of equipment indicated in 250.92(A)(1), (A)(2), and (A)(3) shall be effectively bonded together.
(1) The service raceways, cable trays, cablebus framework, auxiliary gutters, or service cable armor or sheath except as permitted in 250.84.
(2) All service enclosures containing service conductors, including meter fittings, boxes, or the like, interposed in the service raceway or armor.
(3) Any metallic raceway or armor enclosing a grounding electrode conductor as specified in 250.64(B). Bonding shall apply at each end and to all intervening raceways, boxes, and enclosures between the service equipment and the grounding electrode.
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And then applying part B of the same section. I now see that 250.92(A)(3) is not in the 2008 code. However a quick at the ROP and ROC does not indicate that this subsection should have been removed from the 2008 code. The proposal, 5-84, was only to remove the following words; "Bonding shall apply at each end and to all intervening raceways, boxes, and enclosures between the service equipment and the grounding electrode." and relocate them to 250.64(E). I did not find a comment on this proposal in the ROC.

Edit, I guess this rule only applies to the GEC at the service equipment and not to the GEC for a SDS which is the scope of this thread.
 
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Guess we got a bit off track from the original XO querry - I too see the removal of this code section in 2008....I wonder what happened between the ROP and the publication to remove this section??
 
dana1028 said:
Guess we got a bit off track from the original XO querry - I too see the removal of this code section in 2008....I wonder what happened between the ROP and the publication to remove this section??
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That wording was still in the draft version of the 2008 code and there is nothing in the ROC that would support its removal. Maybe just a printing error?
 
The Exhibit 250.32, that had been in the 2005 NEC Handbook showing the bonding for the GEC metal raceway for 250.92(A)(3) has been moved and is now designated Exhibit 250.28 and supports the 250.64(E) language.

I'm wondering if this change was the correlation committee believing this language [250.92(A)(3)] belonged in 250.64(E).
 
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