BOX FILL QUESTION

[PEDRO ESCOVILLA]

2008 NEC SECTION 314.16 (B)(1) when dealing with and counting " looped " conductors, does an eguipment grounding conductor also get counted if it loops, or is it counted (or discounted if you will) with the other "one" which pass thru or are made up to the box, which may or may not be more than one:lol:

 

[infinity]

Good question. I would say no. It would make little sense to count a long looped conductor as two when you could have any number of other EGC's and still only need to count one.

 

[Dennis Alwon]

If there is only one egc that loops thru the box then it is counted as one wire. If there are more then one egc's then they still count as one whether they are looped or not. So one is terminated and the other passes thru then I would count it as one conductor total.

 

[tkb]

If any of the wires are spliced in the box, ALL of the EGC's need to be connected together and connected to the box.

 

[jumper]

If any of the wires are spliced in the box, ALL of the EGC's need to be connected together and connected to the box.

I am not sure of that. I believe only the EGCs associated with circuit conductors that are spliced in the the box need to be attached to the box.

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).

 

[al hildenbrand]

2008 NEC SECTION 314.16 (B)(1) when dealing with and counting " looped " conductors, does an eguipment grounding conductor also get counted if it loops, or is it counted (or discounted if you will) with the other "one" which pass thru or are made up to the box, which may or may not be more than one:lol:

All the EGCs, in a box, are counted only as "1". The cubic inch requirement for that "1" is that of the largest gauge of any of the EGCs present in the box.

If the EGC loops or is cut, makes no difference, unless the cut EGCs are of different gauges.

 

[al hildenbrand]

I am not sure of that. I believe only the EGCs associated with circuit conductors that are spliced in the the box need to be attached to the box.

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

So, you saying that an EGC that passes through a j-box, even though other EGCs are present in the box, that the pass-through EGC is not to be connected to the other EGCs nor is it to be connected to the box?

And are you saying that a j-box that contains only a pass-through EGC (uncut) that doesn't connect to a device is NOT to be connected to the box?

Let's say I run a 14/2 NMB into and out of a metal wall box, looped, without cutting the EGC. Then, by your logic, I'm NOT to bond the EGC to the metal wall box?

 

[jumper]

So, you saying that an EGC that passes through a j-box, even though other EGCs are present in the box, that the pass-through EGC is not to be connected to the other EGCs nor is it to be connected to the box?

And are you saying that a j-box that contains only a pass-through EGC (uncut) that doesn't connect to a device is NOT to be connected to the box?

Let's say I run a 14/2 NMB into and out of a metal wall box, looped, without cutting the EGC. Then, by your logic, I'm NOT to bond the EGC to the metal wall box?

I am saying that an EGC need not be connected to a box or to another EGC in that box, if that EGC and its circuit conductors are not spliced or terminated within that box. The whole circuit may pass through if all wires of that circuit remain whole.

 

[al hildenbrand]

Let's say I run a 14/2 NMB into and out of a metal wall box, looped, without cutting the EGC. Then, by your logic, I'm NOT to bond the EGC to the metal box?

Make that a metal box with a blank metal cover (no device).

I am saying that an EGC need not be connected to a box or to another EGC in that box, if that EGC and its circuit conductors are not spliced or terminated within that box. The whole circuit may pass through if all wires of that circuit remain whole.

 

[jumper]

Make that a metal box with a blank metal cover (no device).

Well, since 314.4 leads me 250.112 and I see that this box fits none of the items there, I would say the box does not have to be bonded by the EGC if the NM circuit conductors just pass through.

I would bond it, but required. It seems not.

 

[gndrod]

Illustration misleading

Illustration misleading

I am saying that an EGC need not be connected to a box or to another EGC in that box, if that EGC and its circuit conductors are not spliced or terminated within that box. The whole circuit may pass through if all wires of that circuit remain whole.

Hi jumper,
In the MH illustration, the detail shows conductor exit to the external raceway that is a conduit connector. According to 250.146(D), an isolated grounding terminated on a connector contact is the only time the 'through wiring' is permitted without bonding within the box. The NEC does not give reason for isolated grounding terminations in through-connector circuits that prevent 'ground loops' in signal circuits. This might be a case for better definition changes in the 2014 ROP.

 

[gndrod]

NM?

NM?

Well, since 314.4 leads me 250.112 and I see that this box fits none of the items there, I would say the box does not have to be bonded by the EGC if the NM circuit conductors just pass through.

I would bond it, but required. It seems not.

Using 146(D) NM in conduit will still require EGC bonding within the box if an isolated grounding connector is not used.

 

[jumper]

Hi jumper,
In the MH illustration, the detail shows conductor exit to the external raceway that is a conduit connector. According to 250.146(D), an isolated grounding terminated on a connector contact is the only time the 'through wiring' is permitted without bonding within the box. The NEC does not give reason for isolated grounding terminations in through-connector circuits that prevent 'ground loops' in signal circuits. This might be a case for better definition changes in the 2014 ROP.

I understand the "pass through" option for IG grounds and that the IG ground does not have to be connected to the box it is terminated in, yet thiat is whole different scenario.

Maybe I am missing something you are saying.:?

 

[jumper]

Using 146(D) NM in conduit will still require EGC bonding within the box if an isolated grounding connector is not used.

Al said nothing about conduit or splices in his box.

He asked: if a NM goes into a box and exits without a splice, does the box have to be bonded?

Similar to using a metal box for a pull point with PVC pipe and the conductors are not spliced. Does this box have to be bonded?

 

[gndrod]

Al said nothing about conduit or splices in his box.

He asked: if a NM goes into a box and exits without a splice, does the box have to be bonded?

Similar to using a metal box for a pull point with PVC pipe and the conductors are not spliced. Does this box have to be bonded?

Derek,
I believe the illustration that you presented is what I am referring to that has a conduit connector detail. A plastic box may be a different issue for a feed-thru EGC....but do you know of a rope puller that has ever been able to do that while running the NM cabling? I would like to learn that time-saving technique.

 

[Little Bill]

2008 NEC SECTION 314.16 (B)(1) when dealing with and counting " looped " conductors, does an eguipment grounding conductor also get counted if it loops, or is it counted (or discounted if you will) with the other "one" which pass thru or are made up to the box, which may or may not be more than one:lol:

Good question. I would say no. It would make little sense to count a long looped conductor as two when you could have any number of other EGC's and still only need to count one.

If there is only one egc that loops thru the box then it is counted as one wire. If there are more then one egc's then they still count as one whether they are looped or not. So one is terminated and the other passes thru then I would count it as one conductor total.

This is true, but I see one exception or addition to that. 314.16(B)(5) says if you run an additional set of conductors for isolated receptacles, then as additional volume allowance shall be made based on the largest EGC in the additional set.

 

[jumper]

Derek,
I believe the illustration that you presented is what I am referring to that has a conduit connector detail. A plastic box may be a different issue for a feed-thru EGC....but do you know of a rope puller that has ever been able to do that while running the NM cabling? I would like to learn that time-saving technique.

Don't look at me it was Al's idea/scenario.

 

[al hildenbrand]

Similar to using a metal box for a pull point with PVC pipe and the conductors are not spliced. Does this box have to be bonded?

Bingo !

 

[jumper]

Bingo !

Al, I think you are corrupting me.

 

[copper chopper]

answer

answer

pedro to answer your ? you need to goto 314.16B5 which states this..
5) Equipment Grounding Conductor Fill.
Where one or
more equipment grounding conductors or equipment bonding
jumpers enter a box, a single volume allowance in accordance
with Table 314.16(B) shall be made based on the largest
equipment grounding conductor or equipment bonding jumper
present in the box. Where an additional set of equipment
grounding conductors, as permitted by 250.146(D), is present
in the box, an additional volume allowance shall be made
based on the largest equipment grounding conductor in the
additional set

What this means is that for all grounds in the box wheather it loops or not you only count the largest size conductor, if there all #12 awg you only count 1 #12awg conductor...even if theres 4 of them....