# NEC reference/#of NM in hole



## MikePEC (Jun 23, 2012)

Can anyone tell me the maximum number of Romex in a 13/16" hole thru stud with fire foam? Local inspector found this issue on last rough and I haven't received code article from him yet? Thanks!


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## Going_Commando (Oct 1, 2011)

However many fit, but what you'll find is some inspectors start talking about "bundling" and will want to apply 310.15(b) whatever that has to due with derating for multiple current carrying conductors in a raceway.


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## MikePEC (Jun 23, 2012)

He said "everything's good except a few holes with 3 cables in them". SMH


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## Chris Kennedy (Nov 19, 2007)

334.80


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## Chris Kennedy (Nov 19, 2007)

Here.



> 334.80 Ampacity.
> The ampacity of Types NM, NMC, and
> NMS cable shall be determined in accordance with 310.15.
> The allowable ampacity shall not exceed that of a 60°C
> ...


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## MikePEC (Jun 23, 2012)

Thanks, never been called on that ever. Normally most we put in a 13/16" hole is three Romex and 6 maybe 7 in a 1 1/2" hole.


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## MHElectric (Oct 14, 2011)

Chris Kennedy said:


> Here.


:thumbsup:


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## sbrn33 (Mar 15, 2007)

Yep, one of the dumber codes out there. No real problems found but the code panel just thought it was the right thing to do.


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## MikePEC (Jun 23, 2012)

My question is? What is sufficient spacing? 2 - 12/2 NM in a half inch whole or a two inch hole. Very vague IMO


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## gold (Feb 15, 2008)

Don't caulk it.


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## Dennis Alwon (May 9, 2009)

MikePEC said:


> My question is? What is sufficient spacing? 2 - 12/2 NM in a half inch whole or a two inch hole. Very vague IMO


It doesn't matter how big the hole is if all the wires are together with caulking.

If you separate the wires in the hole with insulation between then that is another story.

If you are talking about 12 and 14 gauge NM cables then you can have up to 9 current carrying conductor in the caulked hole without an issue-- that could be 3- 2 wire cables and a 3 wire cable or any combination less than 10 current carrying conductor.


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## Dennis Alwon (May 9, 2009)

Goldagain said:


> Don't caulk it.


unfortunately that is not an option with the energy codes.


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## Bugz11B (May 12, 2013)

for 12 gauge romex you can put 9 threw a hole and be fine 30A*.70=21A derated (pending no "neutrals").
for 14 gauge romex you can put 9 threw a hole and be fine 25A*.70= 17.5A derated (pending no "neutrals").

When I say no neutrals if you are unsure of what I mean see 310.15 (B)(4). also take note I assumed 20A overcurrent device for #12 and 15A overcurrent device for #14.


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## Celtic (Nov 19, 2007)

Dennis Alwon said:


> It doesn't matter how big the hole is if all the wires are together with caulking.
> 
> If you separate the wires in the hole with insulation between then that is another story.


Is it?



334.80 said:


> ...Where more than two NM cables containing two or
> more current-carrying conductors are installed, without
> maintaining spacing between the cables, through the same
> opening in wood framing that is to be sealed with *thermal
> ...


Isn't all insulation "thermal insulation"?


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## ceb58 (Feb 14, 2009)

MikePEC said:


> He said "everything's good except a few holes with 3 cables in them". SMH


 Still not a problem. Lets say they are 14-2 and we count both conductors as ccc. So we have 6 ccc and have to derate at 80%. #14 in the 90 deg. is good for 25 amps. 25*.80 = 20 amps your going on a 15 amp breaker so there is no problem. Same as if you had 4-14-2's. you derate by 70% 25 * .70 = 17.5 amps so you are still good on a 15 amp ocp.
Same with 12-2 if you had 8 ccc 30 * .70 = 21 amps


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## Dennis Alwon (May 9, 2009)

Celtic said:


> Is it?
> 
> 
> 
> Isn't all insulation "thermal insulation"?




I think- emphasis on think- that the concept is the bundling together of the wires. If this were not true then installing a panel in the wall with insulation would subject all the circuits to large derating. NO?


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## Bugz11B (May 12, 2013)

Dennis Alwon said:


> It doesn't matter how big the hole is if all the wires are together with caulking.
> 
> If you separate the wires in the hole with insulation between then that is another story.
> 
> If you are talking about 12 and 14 gauge NM cables then you can have up to 9 current carrying conductor in the caulked hole without an issue-- that could be 3- 2 wire cables and a 3 wire cable or any combination less than 10 current carrying conductor.


Addition, if no multi-wire (neutrals) this would become 9 cables. grounded conductors are not counted in derating. 
*I know you mentioned CCC but i see alot of people count grounded conductors when not needed, didnt point as as a correction, more of a clarification)


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## Dennis Alwon (May 9, 2009)

Erik.Schaeffer said:


> Addition, if no multi-wire (neutrals) this would become 9 cables. grounded conductors are not counted in derating.


You mean 9 current carrying conductors - this is true but I am allowed 9 at 70%- not an issue


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## HackWork (Oct 2, 2009)

I don't know what's going on here but it seems as if Erik is saying the grounded conductor isn't a CCC and you can run 9 NM's together.


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## Bugz11B (May 12, 2013)

HackWork said:


> I don't know what's going on here but it seems as if Erik is saying the grounded conductor isn't a CCC and you can run 9 NM's together.


Correct, thank you


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## Celtic (Nov 19, 2007)

Dennis Alwon said:


> I think- emphasis on think- that the concept is the bundling together of the wires. If this were not true then installing a panel in the wall with insulation would subject all the circuits to large derating. NO?


I understand the logic, but can't answer the question.


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## HackWork (Oct 2, 2009)

Erik.Schaeffer said:


> Correct, thank you


I'm still not understanding how you came to that conclusion.


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## ceb58 (Feb 14, 2009)

HackWork said:


> I don't know what's going on here but it seems as if Erik is saying the grounded conductor isn't a CCC and you can run 9 NM's together.


 The grounded conductor would not be counted if it were a multi-wire branch circuit. So if you had 3 14-2's and 1-14-3 that was a MWBC you would have 8 ccc.


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## HackWork (Oct 2, 2009)

ceb58 said:


> The grounded conductor would not be counted if it were a multi-wire branch circuit. So if you had 3 14-2's and 1-14-3 that was a MWBC you would have 8 ccc.


I agree with this.

It seems as if Erik confused where the neutral was counted as a CCC.


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## Bugz11B (May 12, 2013)

Dennis Alwon said:


> I think- emphasis on think- that the concept is the bundling together of the wires. If this were not true then installing a panel in the wall with insulation would subject all the circuits to large derating. NO?


In school they defined bundling as "2 consecutive feet with no air space between cables", another thing we went over (I knew I kept my notebook for something), Also the reason for needing to derate romex when threw wood is because wood is a "combustible framing member", Im fairly certain no such rules apply when going threw metal frames (not 100% on that)


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## Bugz11B (May 12, 2013)

ceb58 said:


> The grounded conductor would not be counted if it were a multi-wire branch circuit. So if you had 3 14-2's and 1-14-3 that was a MWBC you would have 8 ccc.


No sir. 
3 14/2's = 3 CCC
1 14/3= 3 CCC
total of 6 CCC


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## Bugz11B (May 12, 2013)

HackWork said:


> I agree with this.
> 
> It seems as if Erik confused where the neutral was counted as a CCC.


310.15 (B)(4) a,b

I think you have that backwords... re-read (b)...

EDIT*** 310.15 (B) (5) a-b (sorry was looking in 2008 code, but the facts are still the same)


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## HackWork (Oct 2, 2009)

Erik.Schaeffer said:


> 310.15 (B)(4) a,b
> 
> I think you have that backwords... re-read (b)...


A shows what you said is wrong and B has nothing to do with this.


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## MikePEC (Jun 23, 2012)

So if I follow correctly my 1 1/2" hole (which size doesn't matter) with 7 - 12/2 Romex is compliant?


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## Celtic (Nov 19, 2007)

Erik.Schaeffer said:


> In school they defined bundling as "2 consecutive feet with no air space between cables",...


Defined by whom?


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## Bugz11B (May 12, 2013)

A= A neutral conductor that carries only the unbalanced current from other conductors of the SAME circuit SHALL NOT be required to be counted when applying the provisions of 310.15(B)(2)(a)


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## HackWork (Oct 2, 2009)

Erik.Schaeffer said:


> A= A neutral conductor that carries only the unbalanced current from other conductors of the SAME circuit SHALL NOT be required to be counted when applying the provisions of 310.15(B)(2)(a)


The grounded conductor in a 2-wire circuit is not "_A neutral conductor that carries only the unbalanced current from other conductors of the SAME circuit_"


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## Bugz11B (May 12, 2013)

Celtic said:


> Defined by whom?


that was a note in my notebook, NCCER/NFPA? would be a point of debate I dont care enough to have, its what I was taught and is taught in every school that uses a NCCER curriculum (nationwide). If it is incorrect im sorry.


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## Bugz11B (May 12, 2013)

HackWork said:


> The grounded conductor in a 2-wire circuit is not "_A neutral conductor that carries only the unbalanced current from other conductors of the SAME circuit_"


You are correct my friend.
Its only a neutral if it carries the unbalanced load of 2 phases, you must have a 3-wire circuit to have a neutral. It was a error on the part of NFPA when they put the word "neutral" there, if you were fully correct than that whole section would be pointless, the only error there is using the word "neutral" because all the words folling it make it impossible for it to be a neutral


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## Celtic (Nov 19, 2007)

Erik.Schaeffer said:


> that was a note in my notebook, NCCER/NFPA? would be a point of debate I dont care enough to have, its what I was taught and is taught in every school that uses a NCCER curriculum (nationwide). If it is incorrect im sorry.


It is not defined as such in the NEC [NFPA publication] and therefore is not bound by any other publications definition and/or opinion.


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## HackWork (Oct 2, 2009)

Erik.Schaeffer said:


> You are correct my friend.
> Its only a neutral if it carries the unbalanced load of 2 phases, you must have a 3-wire circuit to have a neutral. It was a error on the part of NFPA when they put the word "neutral" there, if you were fully correct than that whole section would be pointless, the only error there is using the word "neutral" because all the words folling it make it impossible for it to be a neutral


I disagree. The word "neutral" fits in there perfectly.


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## MikePEC (Jun 23, 2012)

Erik.Schaeffer said:


> for 12 gauge romex you can put 9 threw a hole and be fine 30A*.70=21A derated (pending no "neutrals").
> for 14 gauge romex you can put 9 threw a hole and be fine 25A*.70= 17.5A derated (pending no "neutrals").
> 
> When I say no neutrals if you are unsure of what I mean see 310.15 (B)(4). also take note I assumed 20A overcurrent device for #12 and 15A overcurrent device for #14.


So you're saying I have a case when I call inspector tomorrow? And thanks for all the info guys!


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## Speedy Petey (Jan 10, 2007)

MikePEC said:


> So you're saying I have a case when I call inspector tomorrow? And thanks for all the info guys!


Yes, definitely.
It's not that it's not allowed, it's that it is only allowed after derating.

Basically you can have up to four cables before you have to worry about things.


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## ceb58 (Feb 14, 2009)

Erik.Schaeffer said:


> No sir.
> 3 14/2's = 3 CCC
> 1 14/3= 3 CCC
> total of 6 CCC





Erik.Schaeffer said:


> A= A neutral conductor that carries only the unbalanced current from other conductors of the SAME circuit SHALL NOT be required to be counted when applying the provisions of 310.15(B)(2)(a)


You need to look at your notes again. For example in a 14-3 mwbc the neutral is carrying the unbalanced load between the phases and would not be counted. In a 14-2 the neutral will be carrying the same amount as the ungrounded therefore it is counted. So 3-14-2's and 1-14-3 as a mwbc would total 8 ccc.


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## ceb58 (Feb 14, 2009)

MikePEC said:


> So you're saying I have a case when I call inspector tomorrow? And thanks for all the info guys!


 Yes you have a great case. I was flagged by an inspector saying they only wanted 2 cables per hole. When I challenged him with the same code references he laughed and said most electricians he runs into don't know how to figure the derating so he just tells them 2 per hole. Passed inspections.


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## Dennis Alwon (May 9, 2009)

I have a feeling we have been trolled again.... It never stops.


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## Bugz11B (May 12, 2013)

Dennis Alwon said:


> I have a feeling we have been trolled again.... It never stops.


If you referring to me, I don't intentionally troll, I have been looking threw notes to see where I may have got this confused since hackwork mentioned I may be looking at it wrong, when speaking electrical I won't troll, and I admit when I realize I'm mistaken, here is my issue, they say "the same circuit" how can they say that and mean a multiwire which requires 2 circuits, to prevent aimless chatter I decided to look into it and see where I may have mis interpreted it. I am leaning towards him being correct because he's right they say neutral and unbalanced load, 2 sure traits of a multiwire circuit.
I'm never afraid to admit if I'm wrong, I just like to know in my heart of hearts I am.
I did troll Electrically my first day but it was so fun, however no more, not in a serious electrical discussion.


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## sbrn33 (Mar 15, 2007)

I don't see that DA. By hackwork? His answers seem right on, By erik? maybe.


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## Bugz11B (May 12, 2013)

And right here in my notes what do I see? That I was mistakin. Glad to know, this is exactly why I joined the site, to get my brain back to thinking about things I don't do daily. Fortuneitly as a personal rule I don't bundle more then 4 romex cables. Keeps it neat looking.


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## Bugz11B (May 12, 2013)

Celtic said:


> It is not defined as such in the NEC [NFPA publication] and therefore is not bound by any other publications definition and/or opinion.


How does the NEC/NFPA define bundling bud?


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## Bugz11B (May 12, 2013)

Next post. Phone error here.


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## Bugz11B (May 12, 2013)

310.15 (3)(a) 
https://law.resource.org/pub/us/code/ibr/nfpa.nec.2011.html


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## Jlarson (Jun 28, 2009)

sbrn33 said:


> Yep, one of the dumber codes out there. No real problems found but the code panel just thought it was the right thing to do.


Yeah if putting large numbers of the evil NM through one hole was a real problem we'd have a lot of problems here :laughing:


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## MikePEC (Jun 23, 2012)

Just got off phone with inspector ..... Was a bunch of ahhhh well ahhh ill have to get my code book and find the exception to using the table at 310.15(b)(2)(a). He's telling me the derating doesn't pertain to it?? He says just drill a hole next to existing hole and spread out wires amongst the existing hole and new hole. From the way you code experts talk its not the size of the hole! FML


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## electricmanscott (Feb 11, 2010)

Inspector is a moron.


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## Bugz11B (May 12, 2013)

MikePEC said:


> Just got off phone with inspector ..... Was a bunch of ahhhh well ahhh ill have to get my code book and find the exception to using the table at 310.15(b)(2)(a). He's telling me the derating doesn't pertain to it?? He says just drill a hole next to existing hole and spread out wires amongst the existing hole and new hole. From the way you code experts talk its not the size of the hole! FML


Could be a local code. Here (South Florida) if they fail you they MUST provide the reason- code art and or local code. If its the same there he should be able to provide a reason why, if its local code thats something you may want to familiarize yourself with.


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## raider1 (Jan 22, 2007)

MikePEC said:


> Just got off phone with inspector ..... Was a bunch of ahhhh well ahhh ill have to get my code book and find the exception to using the table at 310.15(b)(2)(a). He's telling me the derating doesn't pertain to it?? He says just drill a hole next to existing hole and spread out wires amongst the existing hole and new hole. From the way you code experts talk its not the size of the hole! FML


How does derating not pertain to Table 310.15(B)(2)(a)???????

The inspector is confused.

You don't need to drill a new hole and spread the cables out. If you don't have more than 4 NM cables in a hole that is to be draftstopped or fireblocked with expanding foam then you are code compliant with the ampacity adjustments.

Chris


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## Speedy Petey (Jan 10, 2007)

MikePEC said:


> Just got off phone with inspector ..... Was a bunch of ahhhh well ahhh ill have to get my code book and find the exception to using the table at 310.15(b)(2)(a). He's telling me the derating doesn't pertain to it?? He says just drill a hole next to existing hole and spread out wires amongst the existing hole and new hole. From the way you code experts talk its not the size of the hole! FML


So how does he explain:


> 334.80 Ampacity.
> The ampacity of Types NM, NMC, and
> NMS cable shall be determined in accordance with 310.15.
> The allowable ampacity shall not exceed that of a 60°C
> ...


He's not confused, he's a moron. :whistling2:


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## HackWork (Oct 2, 2009)

MikePEC said:


> Just got off phone with inspector ..... Was a bunch of ahhhh well ahhh ill have to get my code book and find the exception to using the table at 310.15(b)(2)(a). He's telling me the derating doesn't pertain to it?? He says just drill a hole next to existing hole and spread out wires amongst the existing hole and new hole. From the way you code experts talk its not the size of the hole! FML


You should say to him "_Buddy, you need to get up to date with your code._"


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## Dennis Alwon (May 9, 2009)

I really don't buy this concept as an issue although I know it is code. How does drilling thru 3" of plates with foam affect the cable. When there is a crawl space below the hole is not caulked from the bottom just at the top. Sure it expands but why doesn't 310.15 (A)(2) come into play. Basically 334.80 tells us to ignore 310.15(A)(2) and yet we can install an entire panel with all the homeruns and smother it with open cell foam-- 


Better yet- I have a 4 or 6 gang switch box fed from 1 or 2 circuits yet if all 6 switch legs go thru the same hole I have to count each set of 2 wire cables as 2 current carrying conductor. Why? Same can be said for 3 way switches


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## Celtic (Nov 19, 2007)

Erik.Schaeffer said:


> How does the NEC/NFPA define bundling bud?



I seem to have missed an "If" in my post...



Celtic said:


> *If* it is not defined as such in the NEC [NFPA publication] and therefore is not bound by any other publications definition and/or opinion.


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## MikePEC (Jun 23, 2012)

Inspector hasn't called me back yet but just talked to his boss. He says max of 4 Romex considering their 12or 14/2 with 1 black and one white per cable which makes two current carrying conductors. He's days the "picture" 2008 code book defines it perfectly.


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## ceb58 (Feb 14, 2009)

MikePEC said:


> Inspector hasn't called me back yet but just talked to his boss. He says max of 4 Romex considering their 12or 14/2 with 1 black and one white per cable which makes two current carrying conductors. He's days the "picture" 2008 code book defines it perfectly.


Your still dealing with morons. You could have 3 -14/2 or 12/2 and one 14/3 or 12/3 (mwbc). This would be 9 ccc. Or any other combination of ccc. The cutoff is 9 ccc for derating by 70% to get you in the ampacities of the breakers.

Correction on brain fart mwbc would still be 2 ccc.


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## FastFokker (Sep 18, 2012)

I count a 3 wire as 2 current carrying conductors. But that's just me!


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## HackWork (Oct 2, 2009)

FastFokker said:


> I count a 3 wire as 2 current carrying conductors. But that's just me!


The NEC agrees with you.


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## FastFokker (Sep 18, 2012)

HackWork said:


> The NEC agrees with you.


IMPOSSIBLÉ!

They've been ripping off my ideas for decades.


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## Dennis Alwon (May 9, 2009)

The concept of 4 current carrying conductor's is basically accurate but it really has to do with the number of current carrying conductor's. 

Here is something written by Trevor at Mike Holt
Here's some examples of when to count the neutral as a CCC:



> 208Y/120 volt system-different circuit types:
> 
> A)- 2 wire circuit w/ 1 ungrounded, 1 neutral = 2 CCC's
> B)- 3 wire circuit w/ 2 ungrounded, 1 neutral = 3 CCC's
> ...


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## MikePEC (Jun 23, 2012)

Inspector that failed me returned my call this morning. He says, now that you have brought this to our attention and after my boss and I read the articles wwe r more confused then ever! He goes now I don't think you can have two wires of different ampacities in same hole :001_huh::001_huh:! His resolution for the time being seperate 12/2 and 14/2 in 1 1/2" hole with a shim so there is no more then 4 wires per side.... I says I'm no expert but I'm positive my understand is right, his answer " even tho we are electrical inspectors we aren't code experts. SMH


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## Celtic (Nov 19, 2007)

MikePEC said:


> He goes now I don't think you can have two wires of different ampacities in same hole :001_huh::001_huh:!


What exactly will the ampacity be on a 15A general purpose circuit in a dwelling unit?
Will it be the same as the family grows...and remain constant as it "empty nests"?
Morning, noon and night?

Will that 15A circuit have a larger, smaller or same load as a 20A SABC/bath circuit?
Will it be the same as the family grows...and remain constant as it "empty nests"?
Morning, noon and night?

Hang on Mr. Inspector....








I have a call to make...








it'll be for you...


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## 360max (Jun 10, 2011)

MikePEC said:


> Inspector that failed me returned my call this morning. He says, now that you have brought this to our attention and after my boss and I read the articles wwe r more confused then ever!* He goes now I don't think you can have two wires of different ampacities in same hole *:001_huh::001_huh:! His resolution for the time being seperate 12/2 and 14/2 in 1 1/2" hole with a shim so there is no more then 4 wires per side.... I says I'm no expert but I'm positive my understand is right, his answer " even tho we are electrical inspectors we aren't code experts. SMH


he should not be inspecting electrical installations


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## ceb58 (Feb 14, 2009)

MikePEC said:


> Inspector that failed me returned my call this morning. He says, now that you have brought this to our attention and after my boss and I read the articles wwe r more confused then ever! He goes now I don't think you can have two wires of different ampacities in same hole :001_huh::001_huh:! His resolution for the time being seperate 12/2 and 14/2 in 1 1/2" hole with a shim so there is no more then 4 wires per side.... I says I'm no expert but I'm positive my understand is right, his answer " even tho we are electrical inspectors we aren't code experts. SMH


Where did you find these morons?
*


 
(3) Adjustment Factors.
 
(a) More Than Three Current-Carrying Conductors in a
Raceway or Cable. Where the number of current-carrying
conductors in a raceway or cable exceeds three, or where
single conductors or multiconductor cables are installed
without maintaining spacing for a continuous length longer
than 600 mm (24 in.) and are not installed in raceways, the
allowable ampacity of each conductor shall be reduced as
shown in Table 310.15(B)(3)(a). Each current-carrying conductor
of a paralleled set of conductors shall be counted as

Click to expand...






a current-carrying conductor.
​​​​​

Click to expand...


You would adjust the conductors by their ampacities for their size. 2-14/2 and 2-12/2. 8 ccc total. The 14 would be at 17.5 amp the 12 at 21 amp your still compliant.​*​​​​​


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## raider1 (Jan 22, 2007)

360max said:


> he should not be inspecting electrical installations


Agreed!

Chris


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