Offset Nipple between Meter and Disco

Status
Not open for further replies.

e57

Senior Member
Fatigue is not an option. :D

Checkmate! :cool:

Edit to add - you put the tuna sandwich on the wrong end of the raceway.
No I did not - it becomes a tuna sanwich in terms of "bonding" right off the neutral buss on the right. And it remains a tuna sandwich clear to the left neutral buss - where it becomes the grounded service conductor again. :D

And - no - this is not over.... ;) :cool:
 

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
I was alerting him to changes that require EACH enclosure to include metering and other enclosures prior to the main(s).
One more time, in English? :-?

Edit to add:
No I did not - it becomes a tuna sanwich in terms of "bonding" right off the neutral buss on the right. And it remains a tuna sandwich clear to the left neutral buss - where it becomes the grounded service conductor again. :D
I need a translation for this one too.
 
Last edited:

e57

Senior Member
One more time, in English? :-?
I did not notice he said isolated in the discconnect - which is hard to believe he would pass any inspections that way... But was alerting him to changes in 250.24 that require the bond in EACH enclosure on the supply side. Which is not applicable to us yet.

Edit to add:

I need a translation for this one too.
My point here and the one from the begining is that while bonding to the grounded service conductor is fine as a method in 250.92(B)1 in one direction from the nipple - but the grounded service conductor itself is not an equipment bonding jumper, or mentioned as a method of providing continuity along the second path/connection of electrical continuity from the nipple to the meter pan.
 

ike5547

Senior Member
Location
Chico, CA
Occupation
Electrician
I did not notice he said isolated in the discconnect - which is hard to believe he would pass any inspections that way...

Actually, I can't remember the last time I used one of those things (single meter only). Maybe never, unless I was ganging them in apartments. I put a main ahead of them in this case.
 
Last edited:

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
But was alerting him to changes in 250.24 that require the bond in EACH enclosure on the supply side. Which is not applicable to us yet.
I hate to break this to you, Mark, but the 2005 NEC's 250.92(A)(2) clearly required bonding on every enclosure on the supply side of the service disconnect.

e57 said:
My point here and the one from the begining is that while bonding to the grounded service conductor is fine as a method in 250.92(B)1 in one direction from the nipple - but the grounded service conductor itself is not an equipment bonding jumper, ...
It does not have to be called an "equipment bonding jumper." It is called a grounded service conductor and if the raceway is connected to it, the section is satisfied.

There is no "direction" specified in the text as to where to connect to. Line side, load side, aft side, port side, connect it to either side as far as the NEC is concerned.

e57 said:
...or mentioned as a method of providing continuity along the second path...
Where in 250.92 does it give two lumps about a "second path"?

...of electrical continuity from the nipple to the meter pan.
The meter pan is bonded inside the meter pan, by means of the neutral directly bolted to the can.
The service disconnect enclosure is bonded by the neutral directly bolted to the neutral can.
The nipple between them is bonded by the connection of a bonding bushing, which is connected to the neutral of the service disconnect enclosure.

All three components are bonded (synonymous with "electrical continuity") and therefore comply with 250.92.

End of story.
 

e57

Senior Member
I hate to break this to you, Mark, but the 2005 NEC's 250.92(A)(2) clearly required bonding on every enclosure on the supply side of the service disconnect.
Don't take the mention of 250.24 out of context to suit yourself or claim that 250.92(A)2 required (or in my case in CA still requires) bonding to the neutral as it does in 250.24 in the '08 NEC - it clearly does not. It too requires effective bonding between enclosures and the methods are laid out in 250.92(B) - and the grounded service conductor is still not mentioned as one of those methods....
2005 NEC said:

250.92 Services.
(A) Bonding of Services. The non-current-carrying metal
parts of equipment indicated in 250.92(A)(l), (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.
As if anything - it serves only to reinforce my points made earlier and the analogies to GEC raceways... And 250.92(B)...

I'll be back after some TV time to play.... It is still not over.... ;) :roll:
 

e57

Senior Member
We can agree to disagree - it's not the first time - or the last...

And I don't see it as a debate one can - WIN... It about what it says and what it does not. It does not say what you say - specifically. And it does not say what I say - specifically. It does not say one end, and it does not say both.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
For what it is worth, a past chairman of CMP5, says that the connection to the enclosure does not satisfy the requirements for bonding a ferrous raceway that contains the GEC. I don't recall a proposal that addressed this specific issue, but have not searched for one.
 

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
I hate to break this to you, Mark, but the 2005 NEC's 250.92(A)(2) clearly required bonding on every enclosure on the supply side of the service disconnect.
Don't take the mention of 250.24 out of context to suit yourself or claim that 250.92(A)2 required (or in my case in CA still requires) bonding to the neutral as it does in 250.24 in the '08 NEC - it clearly does not. It too requires effective bonding between enclosures and the methods are laid out in 250.92(B) - and the grounded service conductor is still not mentioned as one of those methods....
It is the first method listed!!!

I believe I have asked you 14 times now what else you would be bonding to, and you have yet to provide a meaningful answer.

You have not presented a valid response to why you ignore 250.92(B)(1)'s directive telling you to bond to the service neutral.

There is an outside chance that you just don't understand the objective of bonding, let me help you:

250.4(A)(3) Bonding of Electrical Equipment. Normally non? current-carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected together and to the electrical supply source in a manner that establishes an effective ground-fault current path.
e57 said:
2005 NEC said:
250.92(A)(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.
As if anything - it serves only to reinforce my points made earlier and the analogies to GEC raceways... And 250.92(B)...
Unless your GEC is inside the nipple between the meter and service disconnect, your reference is irrelevant. It plainly reiterates 250.64(E), and is equally as specific to raceways and enclosures containing a Grounding Electrode Conductor.

e57 said:
And I don't see it as a debate one can - WIN...
From my seat, I'd say I won it. :D

e57 said:
It does not say what you say - specifically. And it does not say what I say - specifically. It does not say one end, and it does not say both.
The Code is a minimum requirement.

I say I must bond the nipple one time. You say I must bond the nipple two times. Since the code does not spell out that it must be bonded two times, and 1 is less than 2 (last time I checked), then it seems readily evident to me that the lesser requirement is all that can be supported by the text of the NEC.
 

e57

Senior Member
Here we are again....
~
I believe I have asked you 14 times now what else you would be bonding to, and you have yet to provide a meaningful answer.
Each enclosure to each other. By providing electrical continuity between each adjoining enclosure or raceway forming an effective fault current by 'the permanent joining of metallic parts to form an electrically conductive path that ensures electrical continuity and the capacity to conduct safely any current likely to be imposed.' And I usually do that with 'a reliable conductor to ensure the required electrical conductivity between metal parts required to be electrically connected.' Or other listed means - like a bonding locknut, threaded connections of conduit, or treadless connectors made up wrench-tight etc.

George - as it stands now as I am still under the '05 NEC - I do not have to make a connection between the grounded service conductor in each enclosure on the supply side of the main disconnect(s) - I will in the next California electrical code cycle.... I can obtain meters and enclosures without even a means of doing so... In some cases, like with my particular POCO I am in many circumstances required by them to provide a specific enclosure fitting their specifications of dimensions and terminations mounted in it, and no connection between the neutral. In that type of situation can I rely on the neutral to be an effective fault current path - NO. In previous codes the grounded service conductor was not even required to be present in each enclosure. In that type of situation can you rely on the neutral to be an effective fault current path - NO. In the case of ungrounded systems - what do you bond to?

You have not presented a valid response to why you ignore 250.92(B)(1)'s directive telling you to bond to the service neutral.

Your interpretation (a common and popular one) assumes there is another connection between items that should be grounded and the grounded service conductor in enclosures before the main disconnecting means. If there is not one - you have bonded the raceway to a tuna sandwich... As well as the enclosure(s) it is connected to. Only installations after '08 will require that connection be made in other than the main disconnecting means. I hope that persons making future alterations check to make sure there is a connection.

If there is one - you assume that to be a reliable 'electrically conductive path that ensures electrical continuity and the capacity to conduct safely any current likely to be imposed', along a circuitous path without elimination of a path that will still always be present. The connections along that second path that Your interpretation (a common and popular one) ignores (nipple to meter pan in the example we're discussing) also needs to ensure electrical continuity and the capacity to conduct safely any current likely to be imposed'. Otherwise that connection and path is not bonded by definition IMO. Why? Because the grounded service conductor itself is not mentioned as a means of providing electrical continuity fitting the definition of "Bonded" (electrically conductive path) outside of the enclosure it is in, and 250.92(B) there is no FPN or additional item list describing that conductor as a means of providing that. (That is the flaw in the code I'm pointing out to you.) So yes, it may as well be a tuna sandwich.


There is an outside chance that you just don't understand the objective of bonding, let me help you:
Now lets not get condescending... ;)

Lets take some objective looks at things right out of the book... Please take note of the word "PATH" below.

Bonding (Bonded).
The permanent joining of metallic parts to form an electrically conductive path that ensures electrical continuity and the capacity to conduct safely any current likely to be imposed.
~~~~~
Ground-Fault Current Path.
An electrically conductive path from the point of a ground fault on a wiring system through normally non-current-carrying conductors, equipment, or the earth to the electrical supply source.
~~~
(3) Bonding of Electrical Equipment.
Non-currentcarrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected together and to the electrical supply source in a manner that establishes an effective ground-fault current path.
(4) Bonding of Electrically Conductive Materials and Other Equipment.
Electrically conductive materials that are likely to become energized shall be connected together and to the electrical supply source In a manner that establishes an effective ground fault current path.
(5) Effective Ground-Fault Current Path.


Electrical equipment and wiring and other electrically conductive material likely to become energized shall be installed in a manner that creates a permanent, LOW-impedance circuit facilitating the operation of the overcurrent device or ground detector for high-impedance grounded systems.
It shall be capable of safely carrying the maximum groundfault current likely to be imposed on it from any point on the wiring system where a ground fault may occur to the electrical supply source. The earth shall not be considered as an effective ground-fault current path.
250.90 General.
Bonding shall be provided where
necessary to ensure electrical continuity and the capacity to

conduct safely any fault current likely to be imposed.
250.92 Services.
(A) Bonding of Services. The non-current-carrying metal
parts of equipment indicated in 250.92(A)(l), (A)(2), and

(A)(3) shall be effectively bonded together.

Your interpretation (a common and popular one) of bonding only one end of a service raceway:
  1. Assumes there is another connection between items that should be grounded and the grounded service conductor in enclosures before the main disconnecting means.
  2. It also assumes that a second path of current does not exist.
  3. It additionally assumes that fault current will ignore the laws of physics and not take that second path in whole or in part.
Those are the points I am trying to make. Could you be so kind as to address these points?

~
From my seat, I'd say I won it. :D
I do not see this as a contest. Or a "check-mate" - 'Touche!' type of debate. Nor do I expect a "winner". And I am not trying to 'educate' anyone. I am mearly debating a set of codes that I see a flaw and contradiction in.

Please join me in that debate, and address the 3 points above. ;)

The Code is a minimum requirement.
~
Yes - it is. And it is not without flaws or contradiction... ;)
 
Last edited:

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
you assume that to be a reliable 'electrically conductive path that ensures electrical continuity and the capacity to conduct safely any current likely to be imposed', along a circuitous path without elimination of a path that will still always be present.
The connections along that second path that Your interpretation (a common and popular one) ignores (nipple to meter pan in the example we're discussing) also needs to ensure electrical continuity and the capacity to conduct safely any current likely to be imposed'.
This last sentence is the crux of the matter. Why does every path need to be a low-impedance path? The usual notion of "bonded" is just that every point be connected to at least one low-impedance path. What language supports "every path" as opposed to "every point connected to some path"?

Cheers, Wayne
 

e57

Senior Member
This last sentence is the crux of the matter. Why does every path need to be a low-impedance path? The usual notion of "bonded" is just that every point be connected to at least one low-impedance path. What language supports "every path" as opposed to "every point connected to some path"?

Cheers, Wayne
Because the other path is still there. ;)

An electrically conductive path from the point of a ground fault on a wiring system through normally non-current-carrying conductors, equipment, or the earth to the electrical supply source.
 
Status
Not open for further replies.
Top