Grounding 24x24 box

[GoldDigger]

One conjecture is that if there is a splice or termination in a hot conductor you would like the return path from a ground fault to include the associated EGC too, not just one bonded EGC from another circuit.
Not quite sure why, but it feels like that should be better.
If you have different EGCs, at a minimum you need to bond the largest one. But having all if them together as part of the return path reduces the fault clearing impedance. And therefore the voltage offset of grounded metal in the time before the OCPD operates.

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[jap]

One conjecture is that if there is a splice or termination in a hot conductor you would like the return path from a ground fault to include the associated EGC too, not just one bonded EGC from another circuit.
Not quite sure why, but it feels like that should be better.
If you have different EGCs, at a minimum you need to bond the largest one. But having all if them together as part of the return path reduces the fault clearing impedance. And therefore the voltage offset of grounded metal in the time before the OCPD operates.

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That's assuming the hot conductor that shorts out is the one that is spliced in the box.
There's no way of knowing that.

In a real world scenario, lets use all small branch circuits of the same size for instance.
It's very common that the contractor is going to pull all the runs at one time using the same 500' roll of wire for the EGC.

Say he pulls in 14 runs straight through the J-box, but, his roll of green runs out on the 15th pull, so he has to splice it in the box.
Does he then have to cut the 14 EGC's that he just pulled straight through and combine them all together to satisfy the rule?


JAP>

 

[jap]

If we however have circuits of all different sizes, and, we say we need to bond the largest EGC in the J-box, and, that large 200 amp circuit happens to be one of the first ones we pulled in, and straight through, when our #12 EGC we pulled in in the 15th run ran short, and we had to cut the #6 EGC of the 200a feeder to bond it to the box, which is now too short to land it on a single Ground bar or ground lug in the J-box, well then that doesn't make much sense either.

JAP>

 

[Smart $]

If we however have circuits of all different sizes, and, we say we need to bond the largest EGC in the J-box, and, that large 200 amp circuit happens to be one of the first ones we pulled in, and straight through, when our #12 EGC we pulled in in the 15th run ran short, and we had to cut the #6 EGC of the 200a feeder to bond it to the box, which is now too short to land it on a single Ground bar or ground lug in the J-box, well then that doesn't make much sense either.

JAP>

Here's the section...

250.148 Continuity and Attachment of Equipment
Grounding Conductors to Boxes. Where circuit conductors
are spliced within a box, or terminated on equipment
within or supported by a box, any equipment grounding conductor(s)
associated with those circuit conductors shall be connected
within the box or to the box with devices suitable for
the use in accordance with 250.148(A) through (E).

Exception: The equipment grounding conductor permitted
in 250.146(D) shall not be required to be connected to the
other equipment grounding conductors or to the box.

(A) Connections. Connections and splices shall be made
in accordance with 110.14(B) except that insulation shall
not be required.

(B) Grounding Continuity. The arrangement of grounding
connections shall be such that the disconnection or the
removal of a receptacle, luminaire, or other device fed from
the box does not interfere with or interrupt the grounding
continuity.

(C) Metal Boxes. A connection shall be made between the
one or more equipment grounding conductors and a metal
box by means of a grounding screw that shall be used for
no other purpose, equipment listed for grounding, or a
listed grounding device.

(D) Nonmetallic Boxes. One or more equipment grounding
conductors brought into a nonmetallic outlet box shall
be arranged such that a connection can be made to any
fitting or device in that box requiring grounding.

(E) Solder. Connections depending solely on solder shall
not be used.

That's about as straightforward as you can get in my mind.

 

[jap]

Here's the section...



That's about as straightforward as you can get in my mind.

The part that says "associated with those circuits" is what makes the difference.

JAP>

 

[jap]

So if a splice is made in a box, then only the EGC's "associated with that particular circuit" is required to be spliced in the box and bonded to the box.

JAP>

 

[texie]

Here's the section...



That's about as straightforward as you can get in my mind.

All the discussion so far seems to be centered on the 2014 NEC. Isn't this the reason that they made some language changes in 250.148 for 2017 to make it clear that all EGCs would would have to be bonded to the box if even 1 was spliced?

 

[jap]

All the discussion so far seems to be centered on the 2014 NEC. Isn't this the reason that they made some language changes in 250.148 for 2017 to make it clear that all EGCs would would have to be bonded to the box if even 1 was spliced?

If that's true then I'm back to what's the point of that rule.

JAP>

 

[Smart $]

All the discussion so far seems to be centered on the 2014 NEC. Isn't this the reason that they made some language changes in 250.148 for 2017 to make it clear that all EGCs would would have to be bonded to the box if even 1 was spliced?

IMO the 2017 change in the wording can be taken to mean what it has in earlier versions.

250.148 Continuity and Attachment of Equipment
Grounding Conductors to Boxes. Where circuit conductors
are spliced within a box, or terminated on equipment
within or supported by a box, any equipment grounding conductor(
s) associated with those circuit conductors shall be connected
within the box or to the box with devices suitable for
the use in accordance with 250.148(A) through (E).

250.148 Continuity and Attachment of Equipment
GroundingConductors to Boxes. If circuit conductors
are spliced within a box or terminated on equipment within
or supported by a box, all equipment grounding conductor(s)
associated with any of those circuit conductors shall be
connected within the box or to the box with devices suitable
for the use in accordance with 250.8 and 250.148(A) through (E).

 

[jap]

IMO the 2017 change in the wording can be taken to mean what it has in earlier versions.

The argument as to how many EGC's would need to be tied together and bonded to the box would start with what all EGC's were "associated" with the conductors that were spliced in the J-box, would it not?


JAP>

 

[MAC702]

The argument as to how many EGC's would need to be tied together and bonded to the box would start with what all EGC's were "associated" with the conductors that were spliced in the J-box, would it not?

Agreed.

 

[Smart $]

The argument as to how many EGC's would need to be tied together and bonded to the box would start with what all EGC's were "associated" with the conductors that were spliced in the J-box, would it not?


JAP>

Agreed.

Then why would the requirement even use the word associated. All grounding conductors are associated by their very nature. Just say what you mean. If circuit conductors are spliced or terminated within a metal box, all grounding conductors within the box shall be connected together and to the box... and so on.

 

[jap]

Just say what you mean. If circuit conductors are spliced or terminated within a metal box, all grounding conductors within the box shall be connected together and to the box... and so on.

If it actually said just that,then there would be no confusion, but it doesn't.

It says the EGC's "associated" with that circuit.

To me, the way it reads is if 30 or however many circuits with and EGC were pulled straight through a large J-box and those conductors were not spliced, then there would be no need for a bond to the box, but, If I add another circuit, that passes through that J-box, and I splice that particular circuit, then I'm required to splice the EGC that is "associated" with that circuit and bond it to the box.

I don't see where when I added that 1 additional spliced circuit to the J-box that didn't have any splices in it to begin with, where I'd be required to cut all the existing non-spliced EGC's and splice them together and bond all of them to the box just because I added 1 circuit that I did splice.


JAP>

 

[MAC702]

Then why would the requirement even use the word associated. All grounding conductors are associated by their very nature. Just say what you mean. If circuit conductors are spliced or terminated within a metal box, all grounding conductors within the box shall be connected together and to the box... and so on.

Seems to me that the very use of the word "associated" means it is NOT all. For example: Circuit 22 is not spliced. Circuit 22's EGC is not associated with Circuit 20, which has its own. Circuit 20 is spliced, and its associated EGC is therefore spliced and bonded to the box. Circuit 22's EGC therefore has no need to be spliced and bonded, and can run continuously through with Circuit 22's CCCs.

 

[jap]

In my mind the bonding of the box should not be dependent on whether or not a circuit is spliced in that particular box or not.
The box needs to be bonded regardless of the size of the circuit or the number of circuits spliced inside the box.

Maybe it does say that in one way or the other.

JAP>

 

[MAC702]

...the J-box that didn't have any splices in it to begin with,...

To clarify, one of the EGC's would have to be spliced and bonded to the box from the beginning, even if none of the CCCs are spliced, right?

 

[jap]

Seems to me that the very use of the word "associated" means it is NOT all. For example: Circuit 22 is not spliced. Circuit 22's EGC is not associated with Circuit 20, which has its own. Circuit 20 is spliced, and its associated EGC is therefore spliced and bonded to the box. Circuit 22's EGC therefore has no need to be spliced and bonded, and can run continuously through with Circuit 22's CCCs.

I completely agree, and, that's the way I see it also, but, that doesn't make perfect sense either.

To me the box must be bonded regardless of what is taking place inside of it.

JAP>

 

[jap]

To clarify, one of the EGC's would have to be spliced and bonded to the box from the beginning, even if none of the CCCs are spliced, right?

What if a 20 amp circuit was pulled straight through the box and was the only circuit there in the beginning and a #12 EGC was jumper to the box to bond it, then, we came along and pulled a 100 amp feeder straight through that box with a #8 EGC, would we then need to bond the #8 EGC to the box instead of the original #12 bonding since the existing #12 bonding jumper is now not large enough for the 100a Feeder ?


JAP>

 

[ActionDave]

To me the box must be bonded regardless of what is taking place inside of it.

JAP>

And if you have a box bonded by metallic conduit then you don't need a wire EGC. Agree?

 

[jap]

I do not agree by the way it is worded.

I would only agree if a wire type EGC was not installed in the conduit to begin with.

JAP>