# ground fault path



## Zaped (Jul 6, 2008)

In building 3 in attached pic (Exhibit 250.17, 2008 NEC Handbook), where is the ground fault path from EGC bus back to the source ? 

(CORRECTION: there is a neutral to ground jumper present in the pic of my OP--which pic came from the 2005 NEC. But in that "same" pic in my 2008 NEC Handbook, there is no such jumper present, and also no path otherwise for ground fault current path for building 3) ( the lack of ground fault current path for building 3, in my '08 NEC Handbook pic, seems to have been remedied in the '11 NEC...see that pic provided by Celtic below in this thread ).


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## BBQ (Nov 16, 2010)

The grounded (neutral) conductor. 

Notice the neutral is bonded to the grounding bar.


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## Celtic (Nov 19, 2007)

....from '11


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## BBQ (Nov 16, 2010)

Celtic said:


> ....


That is not the same as the OPs file.


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## Zaped (Jul 6, 2008)

BBQ said:


> That is not the same as the OPs file.


BBQ, Correct. Celtic posts a nice pic, but the pic of my original post is different. My original quesiton remains. Thanks.

(see correction elsewhere in thread. Thanks. Zaped.)


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## Celtic (Nov 19, 2007)

...from the '05


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## BBQ (Nov 16, 2010)

Zaped said:


> BBQ, Correct. Celtic posts a nice pic, but the pic of my original post is different. My original quesiton remains. Thanks.


And my original answer remains the same, the ground fault path from panel 3 back to the source is via the neutral.

Just like it is from the service panel back to the source.


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## BBQ (Nov 16, 2010)

Celtic said:


> ...from the '05


Thanks, you had me all messed up with the first posting. :jester:


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## Zaped (Jul 6, 2008)

Celtic said:


> ....from '11


Celtic, nice pic...but different from pic in OP. The lack of ground fault current path, as shown in pic in original post (from 2005 NEC Handbook), is a lack of ground faulth path for...BUILDING 3.

But the pic you provide and cite as being from '11 NEC, which pic is a different pic from my OP, makes me wonder if the different pic is a case of they 'corrected' a mistake in the earlier edition(s) and put the corrected pic in the '11 NEC. Hmmm.

--Zaped


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## Celtic (Nov 19, 2007)

Zaped said:


> Celtic, nice pic...but different from pic in OP. The lack of ground fault current path, as shown in pic in original post (from 2008 NEC, and same as 2005 NEC), is a lack of ground faulth path for...BUILDING 3.
> 
> But the pic you provide and cite as being from '11 NEC, which pic is a different pic from my OP, makes me wonder if the different pic is a case of they 'corrected' a mistake in the earlier edition(s) and put the corrected pic in the '11 NEC. Hmmm.
> 
> --Zaped


There is a change from '05 to '08...
....I don't have the '08 NECH....
....no change from '08 to '11.


Florida is on the '08 code cycle?


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## BBQ (Nov 16, 2010)

Here is the OPs file


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## Zaped (Jul 6, 2008)

*ground fault current path*



BBQ said:


> The grounded (neutral) conductor.
> 
> Notice the neutral is bonded to the grounding bar.


 
BBQ, thanks. No, in the pic in original post, the neutral is not bonded to the EGC bar (for BUILDING THREE(3) ), and that is what prompted the question of my original post.

But the pic Celtic providee, and cite as being from '11 NEC, may be a 'corrected' pic that more less 'solves the problem' of a lack of ground fault path for building 3. ( but the 'solution' as shown in the pic, apparently from the '11 edition of NEC, is a solution that is interesting....i.e., running an equipment bonding conductor from building 3 EGC bus bar to building 2 EGC bus bar. That's interesting. )

Again, I guess the pic from the '11 NEC is a correction of an error in earlier NEC edition. What say you? Does it appear that way to you ?

Thanks, Zaped


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## BBQ (Nov 16, 2010)

Zaped said:


> BBQ, thanks. No, in the pic in original post, the neutral is not bonded to the EGC bar (for BUILDING THREE(3) ), and that is what prompted the question of my original post.


Look again, the file you posted in the first post has a jumper from neutral bar to the ground bar in panel 3.


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## Zaped (Jul 6, 2008)

BBQ said:


> Here is the OPs file


 (( see my subsequent correction further down the thread.
Thanks, Zaped)).
BBQ, thanks. Again, nice jpg pic you provide. But that pic is different from the pic in my original post. (where did you get your jpg pic?). I have the 2008 Handbook open to the Exihit 250.17 right in front of me as I speak, and that pic of your post is different from my book (in my 2008 NEC, for building 3, the bonding jumper between EGC bus and neutral bus DOES NOT EXIST).

Also, in the pic (from my 2008 NEC Handbook)....

from building 1 to building 2...feeder is existing feeder
from building 2 to building 3...feeder is new feeder.

Since feeder from building 2 to building 3 is not an 'existing feeder', but a 'new feeder', it would seem to be not code compliant to put a bonding jumper (in building 3) between EGC bus and neutral bus (i.e., illegal re-bonding in subpanel). But...the pic Celtic provided, and cite as being from '11 NEC, provides an equipment bonding jumper from EGC bus in building 3 to EGC bus in building 2--which seems to be a 'correction' of earlier NEC and also seems to be a nice solution--as far as I can judge--for providing a faulth current path missing in earlier NEC edition pic.

(P.S. -- I am glad to get this much resolution on the question, because the lack of a faulth current path (for building 3), a lack that exists in the pic in the '08 NEC handbook setting in front of me, was nagging the heck out of me.).

Thanks, Zaped


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## Zaped (Jul 6, 2008)

*ground fault*



BBQ said:


> Look again, the file you posted in the first post has a jumper from neutral bar to the ground bar in panel 3.


 
BBQ, thanks. You're right, the pic of my original post does have a jumper (from neutral bar to the ground bar in panel/building3). I am laughing at myself for overlooking that, but not totally laughing at myself. Because here's the rub still...my '08 NEC Handbook, setting right in front of me, DOES NOT HAVE THAT JUMPER in the pic. ( but I had grabbed the "same" pic from a pdf of the 2005 NEC Handbook edition, WITHOUT NOTICING THAT THE JUMPER WAS PRESENT IN THE 2005 PIC. I guess I was going fast enuf that I missed that detail.). So, the moral of the story, I think, subject to revision if later needed, is that the pic in my 2008 NEC Handbook may be in error in that it lacks that jumper for building 3--but that jumper indeed should not be present in a sub panel anyhow (i.e., illegal re-bonding in a sub panel. I forgot what year the Code changed on that.), and without providing otherwise for a fault current path for building three. But if you look in the pic Celtic provided (from '11 NEC), the neutral-to ground jumper for building 3 is not present. Instead, the problem is solved by providing a jumper between building 3 EGC bus and building 2 EGC bus ( I would guess that that EGC bus to EGC bus jumper should have--but was not--included in the '08 NEC. ).

BBQ, thanks again fro noticing my oversight. --Zaped.

(P.S. -- this thread has turned out to be a mini-history in the recent editions of the NEC Handbook ).


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## BBQ (Nov 16, 2010)

Zaped said:


> (where did you get your jpg pic?)


I opened your file on my PC, took a screen shot of it and saved it as a jpeg.


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## Celtic (Nov 19, 2007)

Same pic...



















..no?


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## brian john (Mar 11, 2007)

Zaped said:


> BBQ, thanks. Again, nice jpg pic you provide. But that pic is different from the pic in my original post. (where did you get your jpg pic?). I have the 2008 Handbook open to the Exihit 250.17 right in front of me as I speak, and that pic of your post is different from my book (in my 2008 NEC, for building 3, the bonding jumper between EGC bus and neutral bus DOES NOT EXIST).


The pic you posted and the one I opened is the exact same as the one BBQ posted and Bob is correct.


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## brian john (Mar 11, 2007)

Celtic said:


> There is a change from '05 to '08...
> ....I don't have the '08 NECH....
> ....no change from '08 to '11.
> 
> ...


Does not change physics.


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## Zaped (Jul 6, 2008)

*.*



BBQ said:


> And my original answer remains the same, the ground fault path from panel 3 back to the source is via the neutral.
> 
> Just like it is from the service panel back to the source.


 
BBQ, thanks. You're right. My bad. As noted elsewhere in this thread, the problem is that there are different versions of the pic in different editons of the NEC ( and, in fact, in my hard copy '08 NEC Handbook, right in front of me, there is for building 3 no neutral to ground jumper, which would be illegal as of some recent year anyhow, and also no path otherwise for ground fault current. But the pic from '11 NEC provided by Celtic shows a remedy, and so all is well. ).

--Zaped.


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## Celtic (Nov 19, 2007)

brian john said:


> Does not change physics.


Only changes the pictures


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## Zaped (Jul 6, 2008)

*.*



Celtic said:


> There is a change from '05 to '08...
> ....I don't have the '08 NECH....
> ....no change from '08 to '11.


Celtic. Thanks for the post of the nice '11 NEC pic.

My '08 NECH pic (Exhibit 250.17) is different from the '11 NEC pic you posted...details of that difference noted elsewhere in this thread.

But my original question is nicely resolved by the '11 NEC pic you posted, which '11 pic does show a ground fault return path provided for building 3 (which was lacking in the '08 NECH pic. Unfortunately, I do not have a digital copy of the '08 NECH pic to post. I have just the book in the '08 edition of NECH.).

Thanks. Zaped.


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## Zaped (Jul 6, 2008)

BBQ said:


> I opened your file on my PC, took a screen shot of it and saved it as a jpeg.


 
BBQ, Thanks. Nothing new to add to the many helpful posts all the posters already provided to this thread except the below pic of Exhibit 250.17 from 2008 NEC edition. ( as already commented about in previous posts in this thread, the copy of the 2008 NECH pic shown below lets any observer see the apparent lack of any code-compliant ground fault return path in building three--unless I am missing something (???). Maybe just a simple 2008 publication misprint (???), but in any case has been nicely improved and corrected in the 2011 edition pic already posted elsewhere in this thread. ). --Zaped


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## Zaped (Jul 6, 2008)

Celtic said:


> Only changes the pictures


Thanks. Nothing new here except to say that earlier today I posted above in this thread a copy of the Exhibit 250.17 pic from the 2008 edition of the NECH. --Zaped.


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## di11igaf (Jan 1, 2012)

Zaped said:


> BBQ, Thanks. Nothing new to add to the many helpful posts all the posters already provided to this thread except the below pic of Exhibit 250.17 from 2008 NEC edition. ( as already commented about in previous posts in this thread, the copy of the 2008 NECH pic shown below lets any observer see the apparent lack of any code-compliant ground fault return path in building three--unless I am missing something (???). Maybe just a simple 2008 publication misprint (???), but in any case has been nicely improved and corrected in the 2011 edition pic already posted elsewhere in this thread. ). --Zaped


You didn't miss anything, someone definitely messed that picture up and it was not caught.
Looks like the added green egc jumper was missed from building 2 to 3, and probably revised in a later edition in that same year.


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