# Bundling romex



## kb1jb1 (Nov 11, 2017)

I thought if you bundle then you have to derate the wires. So if the romex is feeding three LED lights then you can derate it 80% and still be OK. I think there are more important things to look at rather then cables under a staple or through a drilled hole. What about cables that are encased in spray foam?


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## Dennis Alwon (May 9, 2009)

The only place where bundling is an issue and it is less than 24" is when the cbles go thru a hole that is filled with firestop, or a thermal insulation.



> 334.80 Ampacity. The ampacity of Types NM and NMC cable shall be determined in accordance with 310.14. The ampacity shall not exceed that of a 60°C (140°F) rated conductor. The 90°C (194°F) rating shall be permitted to be used for ampacity adjustment and correction calculations, provided the final calculated ampacity does not exceed that of a 60°C (140°F) rated conductor. The ampacity of Types NM and NMC cable installed in cable trays shall be determined in accordance with 392.80(A).
> 
> 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 insulation, caulk, or sealing foam, the ampacity of each conductor shall be adjusted in accordance with Table 310.15(C)(1) and the provisions of 310.14(A)(2), Exception, shall not apply.
> 
> *Where more than two NM cables containing two or more current-carrying conductors are installed in contact with thermal insulation without maintaining spacing between cables, the ampacity of each conductor shall be adjusted in accordance with Table 310.15(C)(1)*.


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## Tesla AC (Mar 30, 2013)

If you have 4 cables x 2 conductors per cable or 8 current carrying conductors you should be ok.

using 90 degrees table 310.15(B) (16) and
310.15(B)(3)(a)


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## blueheels2 (Apr 22, 2009)

I’d be interested in knowing if there has ever been one fire started by having more than 4 romexes in a fire stopped hole. Also would like to know if there have been any proven issues from bundling of romex. I think this stuff is tremendous overkill but that’s just my opinion. If proof exists these things are problems I guess I’ll quit crying.


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## 99cents (Aug 20, 2012)

blueheels2 said:


> I’d be interested in knowing if there has ever been one fire started by having more than 4 romexes in a fire stopped hole. Also would like to know if there have been any proven issues from bundling of romex. I think this stuff is tremendous overkill but that’s just my opinion. If proof exists these things are problems I guess I’ll quit crying.


There’s no proof but you can quit crying anyway. 😊


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## eddy current (Feb 28, 2009)

I don’t see why it would be a fail. 

Doesn’t the NEC just say they need to be derated if bundled? And in most cases, wouldn’t they still be able to carry the current of the circuit even after derating?


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## Steve Loew. (Feb 8, 2021)

blueheels2 said:


> I’d be interested in knowing if there has ever been one fire started by having more than 4 romexes in a fire stopped hole. Also would like to know if there have been any proven issues from bundling of romex. I think this stuff is tremendous overkill but that’s just my opinion. If proof exists these things are problems I guess I’ll quit crying.


Most inspectors are DK heads anyway . Can't make it in the trade, become an inspector...That's my quote for the day.


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## Sberry (Jan 11, 2021)

I am going to agree that some bundling may not be a big deal in the real world of residential due to natural loading. How many conductors would see continuous loads of 15 let alone 20?


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## Sberry (Jan 11, 2021)

Sberry said:


> I am going to agree that some bundling may not be a big deal in the real world of residential due to natural loading. How many conductors would see continuous loads of 15 let alone 20?


I was kind of thinking about this during an installation recently where I used 1 multi wire to get away from fill and especially with the advent of LED. I run a pipe with 9 in part of it, 1 conductor has never seen any load, 4 very intermittant above an amp for griner or drill, another 2 have 2 on them and the intermit welding and equipment have wire 2 sizes larger than the minimums if it were single circuit in pipe. Could carry 13K watts before derating was needed and actual is 4K for a few seconds down number10.


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## Dennis Alwon (May 9, 2009)

You have to de-rate according to the nec but it really doesn't affect the ampacity until you have more than 9 current carrying conductor. For instance, #12 @ 90C is rated 30 amps. With 9 current carrying conductor's the demand is 70%. That makes the 30 amp conductors now only good for 21 amps but it doesn't affect the branch circuit which would be at 20 amps anyway


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## Sberry (Jan 11, 2021)

Home inspectors usually work for who is paying them. I had a homeown type say something to me like tht,,, took him right over to the panel and ask,,,, even if you dont know anything about it does this look right? I should have got a pic, didnt think about it. Whoops, maybe I did.


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## JginIndy (Nov 16, 2020)

Steve Loew. said:


> Most inspectors are DK heads anyway . Can't make it in the trade, become an inspector...That's my quote for the day.


I spent well over 20 years as a very successful Electrician before I became an Inspector.


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## Steve Loew. (Feb 8, 2021)

JginIndy said:


> I spent well over 20 years as a very successful Electrician before I became an Inspector.


Lol, some ,not all........................That has been my experience in 50 or so years .


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## JginIndy (Nov 16, 2020)

Steve Loew. said:


> Lol, some ,not all........................That has been my experience in 50 or so years .


Yeah Steve I agree with the “some”
I have found the “butt head” inspectors lack trade and especially code knowledge so they tend to throw out an attitude ( diagnosis....frustrated ) With that said same goes for “some “ that call themselves “Electricians “ as well.


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## Steve Loew. (Feb 8, 2021)

Agree completely........


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## Thirty-eight (Mar 2, 2020)

I drill like a 2.5” hole through a house and run all my home runs through them. Ive never had an inspector complain but I suppose running only 12 gauge or larger I have a case for derating. With all the steel, and lvl’s and glulams that architects spec for heavy snow loads it’s either bundle or Swiss cheese the buildings Structure


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## blueheels2 (Apr 22, 2009)

Thirty-eight said:


> I drill like a 2.5” hole through a house and run all my home runs through them. Ive never had an inspector complain but I suppose running only 12 gauge or larger I have a case for derating. With all the steel, and lvl’s and glulams that architects spec for heavy snow loads it’s either bundle or Swiss cheese the buildings Structure


Yeah I used to live in Vermont and we wired all our McMansions this way.


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## Jimbo4160 (9 mo ago)

blueheels2 said:


> I’d be interested in knowing if there has ever been one fire started by having more than 4 romexes in a fire stopped hole. Also would like to know if there have been any proven issues from bundling of romex. I think this stuff is tremendous overkill but that’s just my opinion. If proof exists these things are problems I guess I’ll quit crying.
> [/QUOTE


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## Steve Loew. (Feb 8, 2021)

100% agree, just more and more rules that make less and less sense. Typical Government thinking ....


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