Bored Holes

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Alex electrical student

Alex electrical student

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How many 12/2 romex wires can you put into a 1 1/2" bored hole? I looked in the code and i found article 310.15(b)(2)(a). What i got out of the article is that i can put as many wires into the hole as i can because this bored hole is in 2 x 6 board. Am i correct?
 
Alex, It boils down to, how are you going to maintain an air space between

the cables from joist to joist. Also, there is no gauge for what the air space

is required to be. So, you maybe right, but you maybe changing your plan.

JMO.
 
The requirements on this seem to change from day to day so I drill a few smaller holes as this is better for the wood beams also. I try not to bundle more than 3 unless forced to and let everyone else argue it out while I pull wire.
 
Many electricians state the maximum number of cables in a bored hole is 3.
There is no code rule to support this. It may be in a 2x4 wall the biggest hole you can drill and maintain 1 1/4" from each face will only allow 3 cables

And don't believe anything you are told. Ask for the code rule
Not "I think".
 
tom baker said:
Many electricians state the maximum number of cables in a bored hole is 3.
There is no code rule to support this. It may be in a 2x4 wall the biggest hole you can drill and maintain 1 1/4" from each face will only allow 3 cables

And don't believe anything you are told. Ask for the code rule
Not "I think".
Click to expand...
There are fire penetrations that come into play also it is not all about the NEC.
 
Alex electrical student said:
How many 12/2 romex wires can you put into a 1 1/2" bored hole? I looked in the code and i found article 310.15(b)(2)(a). What i got out of the article is that i can put as many wires into the hole as i can because this bored hole is in 2 x 6 board. Am i correct?
Click to expand...

If the hole has to be filled with fire caulk then you are limited to 4 wires wires otherwise you would have to upsize your wire due to derating. art 334.80
 
Dennis Alwon said:
If the hole has to be filled with fire caulk then you are limited to 4 wires wires otherwise you would have to upsize your wire due to derating. art 334.80
Click to expand...


Dennis how did you come up with 4 wires? Did you mean 4- 2 wire cables?
 
Alex electrical student said:
How many 12/2 romex wires can you put into a 1 1/2" bored hole? I looked in the code and i found article 310.15(b)(2)(a). What i got out of the article is that i can put as many wires into the hole as i can because this bored hole is in 2 x 6 board. Am i correct?
Click to expand...


The answer yes, you are permitted to install as many as you can fit if the hole has no fire or draft stopping material within the hole.
 
Hypothetical question: If I drilled the biggest hole allowable in a 2X4 and kept my cables 1 1/4" away from the plane of the surface of the 2 by, and I used "stack-its" to maintain the 1/4" spacing through the actual stud hole and used "stack-its" in the free space between studs (horizontally), I think I could put together as many as the hole spacing would allow without "bundling", since I would be maintaining spacing through the stud hole and the free space. Right or not?
This method might be a little more expensive at rough-in, but less drilling time might make up for the expense of the "stack-its".
 
wbalsam1 said:
Hypothetical question: If I drilled the biggest hole allowable in a 2X4 and kept my cables 1 1/4" away from the plane of the surface of the 2 by, and I used "stack-its" to maintain the 1/4" spacing through the actual stud hole and used "stack-its" in the free space between studs (horizontally), I think I could put together as many as the hole spacing would allow without "bundling", since I would be maintaining spacing through the stud hole and the free space. Right or not?
This method might be a little more expensive at rough-in, but less drilling time might make up for the expense of the "stack-its".
Click to expand...

Sounds like a lot of work. Many don't think it is bundling when you run horizontally thru a large hole. I tend to think it is but we don't want to go there.
 
Dennis Alwon said:
Sounds like a lot of work. Many don't think it is bundling when you run horizontally thru a large hole. I tend to think it is but we don't want to go there.
Click to expand...

Yeah, it would be a lot of work, I guess. I was just thinking of a sure-fire, fool-proof way to maintain spacing so that conductors and cables could freely dissipate their heat and do so with a method that wouldn't weaken load-bearing walls with too many holes. :smile:
 
wbalsam1 said:
Yeah, it would be a lot of work, I guess. I was just thinking of a sure-fire, fool-proof way to maintain spacing so that conductors and cables could freely dissipate their heat and do so with a method that wouldn't weaken load-bearing walls with too many holes. :smile:
Click to expand...
The bigger problem for me is when you have a 40 circuit, interior panel and most of the wiring must exit below. What a pain in the butt. You have to drill 10 smaller holes instead of two large one like we use to do.
 
Dennis Alwon said:
The bigger problem for me is when you have a 40 circuit, interior panel and most of the wiring must exit below. What a pain in the butt. You have to drill 10 smaller holes instead of two large one like we use to do.
Click to expand...

as I often say:
"we're here from the inspection department. We are here to help you!" :)
 
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