I was a little confused with the new rules on romex. Can you no longer sleeve all your romex into a 2'' pvc then into the panel to make it look nice. And from what I understand you cant have more than 2 romex in the same hole in a stud? Am i understanding this right? Am i missing anything?
new nec romex rules
- Thread starter fireryan
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Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
Take a look at 312.5(C) for the answer to your PVC question.
In regards to your question on the number of cables through a bored hole, I am wondering from where you are getting this info.
In regards to your question on the number of cables through a bored hole, I am wondering from where you are getting this info.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
This is the last paragraph of art. 334.80
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
fireryan said:
Art. 334.80 allows only 2 wires in a bored hole where thermal insulation, firecaulk, etc will be used-before you must derate.
I have never seen anyone caulk between the studs so that is usually not an issue.
If you put 4 12/2 nm cables in a hole you must derate for 8 current carrying conductors. Table 310.15(B)(2)(a) tells us we must derate 70% to 9 conductors. Since NM cable has 90 C conductors we can use the 30 amp rating from T310.15. 30 times 70% = 21 amps so you are still good. Add that 5 nm cable and you have to lower the ampacity of all the conductors to a 15 amp breaker
Minuteman
Senior Member
- Location
- The Sooner Nation
benaround said:
I'm not sure I follow you Frank.
Minuteman said:I'm not sure I follow you Frank.
That's probally a good thing you don't. Last I knew romex needed to be
supported at the panel by a romex connector, but, that was many,many years ago.
I didn't read 334.30 as ' those cables need physical protection ' as the cables
entering the panel. Hey, that's only twice this week I've been wrong.
- Location
- Massachusetts
fireryan said:
This is covered as Pierre pointed out by 312.5(C) and has strict restrictions.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
fireryan said:
Yes, you can still run them in PVC but take a close look at the Article Pierre posted, 312.5(C). This installation method if very restrictive and it meet all seven conditions outlined in 312.5(C).
Pertaining to 334.80, if a sleeve is used to protect the nm cables through the wood framing and fire stop sealant is used, derating does not apply?? If thermal insulation is used, derating does apply. The reason i say that is because, i am not in direct contact with the wood.
334.80 Ampacity.
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 fire- or draft-stopped using thermal insulation, caulk, or sealing foam, the allowable ampacity of each conductor shall be adjusted in accordance with Table 310.15(B)(2)(a) and the provisions of 310.15(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 allowable ampacity of each conductor shall be adjusted in accordance with Table 310.15(B)(2)(a).
334.80 Ampacity.
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 fire- or draft-stopped using thermal insulation, caulk, or sealing foam, the allowable ampacity of each conductor shall be adjusted in accordance with Table 310.15(B)(2)(a) and the provisions of 310.15(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 allowable ampacity of each conductor shall be adjusted in accordance with Table 310.15(B)(2)(a).
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