Bundling Romex

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220/221

Senior Member
Location
AZ
A/A Fuel GTX said:
OK........I have a dwelling with 2 X 10's as floor joists. I bore 2 1/2" holes through the joists for the length of the dwelling and place my homeruns through these holes. There may be 10 to 15 homeruns passing through some of these holes. They are not fire blocked. The joists are 2' on center. Is this bundling?
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I'd be more concerned about the 2.5" holes in a 2x10



Bundling of any type has never been an issue out here.
 
mcclary's electrical

mcclary's electrical

Senior Member
Location
VA
Article 90.1 said:
Check your local amendments, we have one here that only allows 2 cables per bored hole, period.
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I hope this is a joke. I can think of instances where you could have (4) 14/3's going through one hole to be firestopped,,,,and still only have (8) ccc's. Is that an actual rule? or rule of thumb?
 
A

Article 90.1

Senior Member
Hey guys relax a bit. Yes, I agree, it is a stupid rule. However, it is a legally adopted amendment in the state of Tennessee. I didn't make the rule, and most installers don't follow it. There is one local inspector that will hold you to two NM cables per bored hole though.
 
A/A Fuel GTX

A/A Fuel GTX

Senior Member
Location
WI & AZ
Occupation
Electrician
Article 90.1 said:
Hey guys relax a bit. Yes, I agree, it is a stupid rule. However, it is a legally adopted amendment in the state of Tennessee. I didn't make the rule, and most installers don't follow it. There is one local inspector that will hold you to two NM cables per bored hole though.
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Augie........Enlighten us here. What say you?
 
M

macmikeman

Senior Member
Location
Planet macmikeman
I think the guys on the code panels probably never had their hands on a single piece of romex in their lives, unless it was a short section cut for display at whatever meetings and seminars these guys get to go to. My bets is they are all dyed in the wool solid conduit guys (if they actually do any electrical work, vs the engineer's on the team), who worked in high rises in downtown Manhattan. And conduits getting really hot are not that uncommon to find, whereas romex overloaded to the point of combustion is fairly rare in modern houses if they are wired by real electricians instead of Craigslist coyboys. De-rating and number of conductors in conduits in the code book led to the addition of "bundling" for non metallic cables. It isn't a real problem and probably never caused a fire. (By the way, I have read the full story on the two wires in top plates with fire caulking testing.) Harumph. :roll:
 
Jim W in Tampa

Jim W in Tampa

Senior Member
Location
Tampa Florida
macmikeman said:
I think the guys on the code panels probably never had their hands on a single piece of romex in their lives, unless it was a short section cut for display at whatever meetings and seminars these guys get to go to. My bets is they are all dyed in the wool solid conduit guys (if they actually do any electrical work, vs the engineer's on the team), who worked in high rises in downtown Manhattan. And conduits getting really hot are not that uncommon to find, whereas romex overloaded to the point of combustion is fairly rare in modern houses if they are wired by real electricians instead of Craigslist coyboys. De-rating and number of conductors in conduits in the code book led to the addition of "bundling" for non metallic cables. It isn't a real problem and probably never caused a fire. (By the way, I have read the full story on the two wires in top plates with fire caulking testing.) Harumph. :roll:
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While most here will agree with you and that includes me , the fact is it is now code. Might try to get it removed but more holes means more fire caulk and drill bits. Wonder if money or doughnuts is involved.
 
F

Fred Jones

New member
Bundling Romex ok for #14 and #12 after derating

Bundling Romex ok for #14 and #12 after derating

I just got called for this by inspector. He will not allow more than 2 romex cables in a wood bored hole. He states Article 334.80. After reading and being referred back to 310.15(B)(2)(a) to derate cables as per 334.80. It allows you to derate 7-9 current carrying conductors at 70%. Derating 12/2 70% starting with it's 90 degree ampacity of 30amps as shown in Table 310.16, 30amps X 70% = 21amps derated. It's still a 20amp circuit. The same holds true for 14/2. 90 degree ampacity of 25amps for 14/2 derated 70% is 17amps. Still a 15amp circuit. The 70% derating holds true for up to 9 current carrying conductors as per Table 310.15(B)(2)(a).

So as long as you are bundling only #12 and #14 wire and have no more than 9 current carrying conductors, including neutrals, in a wood bored hole there shouldn't be a code problem after derating.

For those who have or can get there hands on a 2008 HandBook, it explains this in detail after 334.80. Now I need to enlighten the assistant chief inspector to this and I'm not so sure he will be open minded. Wish me luck.

Thanks,
Fred Jones
 
I

insparks

Member
Where does this fall in this discussion

Where does this fall in this discussion

The first photo is the top plate and the second one is the bottom plate and in between they are still loosely together. So Where does this fall in this discussion.
 
mcclary's electrical

mcclary's electrical

Senior Member
Location
VA
Fred Jones said:
I just got called for this by inspector. He will not allow more than 2 romex cables in a wood bored hole. He states Article 334.80. After reading and being referred back to 310.15(B)(2)(a) to derate cables as per 334.80. It allows you to derate 7-9 current carrying conductors at 70%. Derating 12/2 70% starting with it's 90 degree ampacity of 30amps as shown in Table 310.16, 30amps X 70% = 21amps derated. It's still a 20amp circuit. The same holds true for 14/2. 90 degree ampacity of 25amps for 14/2 derated 70% is 17amps. Still a 15amp circuit. The 70% derating holds true for up to 9 current carrying conductors as per Table 310.15(B)(2)(a).

So as long as you are bundling only #12 and #14 wire and have no more than 9 current carrying conductors, including neutrals, in a wood bored hole there shouldn't be a code problem after derating.

For those who have or can get there hands on a 2008 HandBook, it explains this in detail after 334.80. Now I need to enlighten the assistant chief inspector to this and I'm not so sure he will be open minded. Wish me luck.

Thanks,
Fred Jones
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Welcome to the forum,,,,and good point
 
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