Amount of romex in hole

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alcon192

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I am having a hard time finding the amount of romex wires you can run through a hole of any size. I was turned down last week for runnung about 10 romex #14 and #12 through a 1 1/4 hole. The inspector limited me to 3 wires of any size through a vertical hole of any size. He will let me run as many as I want in horizonal holes which I thought was odd. I have wired homes for 20 plus years and first time I have ever had this problem. New area and inspector.:confused:
 
Look at article 334.80 last paragraph. If the hole is going to be fire or draft stopped using foam or thermal insulation you need to derate. I am not sure why he is using 3 cables because 12 thhn is rated 90 degree drerating doesn't affect the 30 amp rating until after 8 conductors. The grounds don't count.
 
NM

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Alcon192, what is posted above is correct NEC 2005, the only difference is if your in Mass. 334.80 was amended, the second paragrah was deleted and first paragraph was rewitten.
 
Dennis Alwon said:
I totally agree. Now the real question. As an inspector-- what do you do? Ignore it or fail it?
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Dennis, I hate to say it and I know 334.80......But I mention it to the EC and we talk about it, and Yes. I do pass it.
 
Multiple romexes through a hole in a stud are only bundled for 1-1/2". I'm not sure how people say they need derated. You can splay the romexes apart a bit in the stud cavity.
 
mdshunk said:
Multiple romexes through a hole in a stud are only bundled for 1-1/2". I'm not sure how people say they need derated. You can splay the romexes apart a bit in the stud cavity.
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If theres fire or draft stopping involved the 24" does not mater. You have to derate after two NM cables.
 
Sometimes the code does not make sense. It is not for a code official to say he does not agree, so he does not enforce that particular code section. Otherwise we would have anarchy.


I do not agree with 2 ground rods, but I enforce it.

And yes, I agree in discussing issues with contractors. That is how they will know about how issues are enforced...allowing him to not meet code will only hurt him in the long run and the industry as well.
 
So, in a nutshell, if I keep my top and bottom plate holes filled with 2 or less NM cables, I'm fine. I can continue to pass as many as possible without damaging the cable through successive bored holes in joists and studs. Asking, not saying.
 
mdshunk said:
So, in a nutshell, if I keep my top and bottom plate holes filled with 2 or less NM cables, I'm fine. I can continue to pass as many as possible without damaging the cable through successive bored holes in joists and studs. Asking, not saying.
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Actually, you can put 4 nm cables through a hole that will be fire stopped without any issues. Nm is rated 30 amp at 90C so 8 conductors is a 70% derate. 70% 0f 30 is and always has been 21 amps.

2) yes as long as there is no firestop. Some inspectors may consider bored holes for more than 2 feet as bundling. I tend to believe it would be unless you separate the cables here and there. That is not likely to happen.
 
Dennis Alwon said:
2) yes as long as there is no firestop. Some inspectors may consider bored holes for more than 2 feet as bundling. I tend to believe it would be unless you separate the cables here and there. That is not likely to happen.
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Thanks for taking the time to respond, Dennis. The reason this concerns me a little is because my normal practice in homes with basements it to drill a series of 2-9/16" holes though the joists or TJI's for all the home runs. Unless you're being anally neat, you can't help but to have interstitial air space between the cables in the joist cavity. They are only bundled for 1-1/2" every 16", in my observation of installed cable.

How do you suppose this rule would effect top plate penetrations with home runs into the panel? Where the normal practice is to remove the top plate and put steel mending plates on both sides?
 
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mdshunk said:
How do you suppose this rule would effect top plate penetrations with home runs into the panel? Where the normal practice is to remove the top plate and put steel mending plates on both sides?
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Yikes-- I never did that-- I always use to bore a 2 9/16 hole or smaller and run all my wires in 2 or 3 holes but this is an issue now.

Your installation will not allow for foam but one could use thermal insulation. Unfortunately the way art. 334.80 reads you would have to derate. I think the only way around this is to use a bunch of 5/8" holes. I am not sure there is enough space in one stud space esp. on a 40 cir. panel.

I plan on using 2 or 3 stud spaces and then bore across where foam is not an issue.

What a pain in the a**
 
mdshunk said:
How do you suppose this rule would effect top plate penetrations with home runs into the panel? Where the normal practice is to remove the top plate and put steel mending plates on both sides?
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I have been thinking about this concept and I do believe that derating would not be necessary if your wires came down the wall stapled 2 together and separated a bit. I can't see how that would be bundling.

Not a bad idea either. It would be a little more difficult to do on the bottom plate but it could be done.
 
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