So how many fricken wires per hole....?

[checkthisout]

So much all over the net....if I really had any patience left I could probably figure it out....or not...

I need to run a few cable(s) like 50 feet through studs.

Just tell me what size hole(s) and how many 12-2/14-2 (or any combination I can get there in there, in a continuous chain/line of holes bundled together.

And, how many I can get a in single hole, and the size of hole when they aren't going to be bundle before or after the hole.

Thanks.

 

[zmaxmotorsports]

Use 7/8-1" holes

 

[rsnip988]

Depends on the local area inspector as to what is "code", I would call to ask.

Mine told me I could use a 5/8" hole and get in 3*14/2 or 2*12/2 per hole. It's difficult to get the 3rd wire to pull through, but you can do it with a little muscle power.
since I was told there isn't a limit to the number of holes per 2x4 (within reason) I just spread them 3 per hole and spread them out about a foot apart vertically.

You can use a larger hole as Zmax stated but if it is a 2x4 you will have to install metal plate covers over EVERY stud you drill through to protect the wires from any screws used to hang an inner wall sheathing...

 

[rodm1]

If you end up drilling joits read before drilling.

http://diy.stackexchange.com/questions/10657/what-are-the-guidelines-for-holes-in-joists

 

[Speedy Petey]

Depends on the local area inspector as to what is "code", I would call to ask.

This is SO not true!

Code is code, not what the inspector wants or makes up.
It's his job to enforce it, not invent it.

That's why they are technically called "Code Enforcement Officers".

You can use a larger hole as Zmax stated but if it is a 2x4 you will have to install metal plate covers over EVERY stud you drill through to protect the wires from any screws used to hang an inner wall sheathing...

This is only true if the holes wind up being closer than 1-1/4" from the edge or face of the framing.

 

[Speedy Petey]

I would also use 7/8" or 1" holes. Bear in mind the requirement to keep any part of the hole at least 1-1/4" from the edge of the framing. This means 1" holes in 2x4's would need to be dead center and dead straight. 7/8' would be a better choice there.

Bottom line for running cables is before derating affects "standard" ampacities for #14, #12 or #10 **/2 or **/3 cables you can run up to four cables in a hole or bundled.
The key here is nine CCC's, or current carrying conductors (hot and neutral). Once you get over nine you run into issues.

 

[MushCreek]

This is SO not true!

Code is code, not what the inspector wants or makes up.
It's his job to enforce it, not invent it.

That's why they are technically called "Code Enforcement Officers".



This is only true if the holes wind up being closer than 1-1/4" from the edge or face of the framing.

Sadly, not all inspectors interpret the codes the same way. I asked one inspector a question about future work on the house I was building, and he said, "Well, I would pass it, but that doesn't mean that one of the other inspectors would." Huh? Also, local jurisdictions can change anything they want. Our local code books specify 'IRC 2006, plus the following amendments...'

 

[sberry]

What is in the amendments?

 

[MushCreek]

Usually just piddly little stuff, but the point is is that local codes can and do vary from 'standard' codes. Ya have to ask the locals to be sure.

 

[Notgrownup]

I always call them if I doubt...they are there to protect us also...Some sub standard practices out there ...

 

[zmaxmotorsports]

This is SO not true!

Code is code, not what the inspector wants or makes up.
It's his job to enforce it, not invent it.

That's why they are technically called "Code Enforcement Officers".



This is only true if the holes wind up being closer than 1-1/4" from the edge or face of the framing.

 

[Slowgsr]

X3 14/2
Anything else x2

10 or larger - X1
Drill 7/8 holes.

 

[Jason280]

I used a 3/4" wood boring bit in my shop build, and was able to pull 3x pieces of 12/2.

 

[Speedy Petey]

X3 14/2
Anything else x2

10 or larger - X1
Drill 7/8 holes.

What does this mean? Only three 14/2? And only two of anything else? And only one #10 cable??

What are you basing this on?
What is the difference between a 14/2 and a 12/2 as far as bundling goes??? (Hint: In the eyes of the code, NOTHING)

 

[AndeiH]

Usually just piddly little stuff, but the point is is that local codes can and do vary from 'standard' codes. Ya have to ask the locals to be sure.

yep, article 90.4 gives the authority having jurisdiction the responsibility of interpreting the rules. they can always ask that higher standards be met, but never anything less than code.

 

[Speedy Petey]

yep, article 90.4 gives the authority having jurisdiction the responsibility of interpreting the rules. they can always ask that higher standards be met, but never anything less than code.

This is the thing, NO, they CANNOT. Not unless there is a written amendment.
You cannot "interpret" the rules to be more than they actually are.

 

[Cmreschke]

Speedy Pete is 100 percent spot on. He can not make the code rules more stringent because he feels like it. What 90.4 means is that an ahj can allow something not normally addressed in the code book, ex using a non listed light fixture is acceptable if the ahj is ok with it.

As for the question about how many cables, you can put any combination of 9 current carrying conductors in a hole when pulling 10s 12s or 14s. Ex 4 12/2s, or 2 12/2s and 2 14/2s.
Fyi 3 wire romex is considered 3 ccc in my oppinion.

 

[wyliesdiesels]

I would also use 7/8" or 1" holes. Bear in mind the requirement to keep any part of the hole at least 1-1/4" from the edge of the framing. This means 1" holes in 2x4's would need to be dead center and dead straight. 7/8' would be a better choice there.

Bottom line for running cables is before derating affects "standard" ampacities for #14, #12 or #10 **/2 or **/3 cables you can run up to four cables in a hole or bundled.
The key here is nine CCC's, or current carrying conductors (hot and neutral). Once you get over nine you run into issues.

Correct me if im wrong but IIRCC NM-b isnt subject to derating when the bundling is less than 24" long...

 

[Cmreschke]

I believe your right about 24 " but curious if it's just for nm b, or doesn't that apply to all wiring types?
Keep in mind your only looking at 2 stud spaces for your 24 ".

 

[Speedy Petey]

Fyi 3 wire romex is considered 3 ccc in my oppinion.

Not for home runs or feed cables in the case of a 120/240V systems. The neutral is expressly not counted.
The neutral is counted in 120/208V or 277/480V wye-connected systems, but that is not a topic for this forum IMO.

310.15(B)(5) Neutral Conductor.

(a) A neutral conductor that carries only the unbalanced current from other conductors of the same circuit shall not be required to be counted when applying the provisions of 310.15(B)(3)(a).

(b) In a 3-wire circuit consisting of two phase conductors and the neutral conductor of a 4-wire, 3-phase, wye-connected system, a common conductor carries approximately the same current as the line-to-neutral load currents of the other conductors and shall be counted when applying the provisions of 310.15(B)(3)(a).

(c) On a 4-wire, 3-phase wye circuit where the major portion of the load consists of nonlinear loads, harmonic currents are present in the neutral conductor; the neutral conductor shall therefore be considered a current-carrying conductor.

 

[Cmreschke]

Yes speedy your mostly right and that is all up to interpretation. I have always felt that unless you can prove that the load is balanced at all times, then it should be counted as a ccc. Example being you pull a 12/3 to the kitchen and feed both small appliance ckts from them, you can't guarantee that your loads are balanced at all times. So therefore your carrying current on your neutral as well.

 

[Cmreschke]

And this is one of those instances where we should try to exceed and be better than the code book. Code may say it doesn't count but....why not do better?

 

[Speedy Petey]

Yes speedy your mostly right and that is all up to interpretation. I have always felt that unless you can prove that the load is balanced at all times, then it should be counted as a ccc. Example being you pull a 12/3 to the kitchen and feed both small appliance ckts from them, you can't guarantee that your loads are balanced at all times. So therefore your carrying current on your neutral as well.

It's really not open to interpretation at all. It's quite black and white.

Yes, in a 3-wire HR the neutral is still a CCC, it's just not carrying anything that the hots are not. All it will ever do is carry the imbalance, so if the load is perfectly balanced it will carry zero.
If both legs are carrying 5A the neutral is carrying 0A. Let's call it 10A
If one leg is carrying 5A and the other 0A then the neutral is carrying 5A. Same 10A
If one leg is carrying 5A, and the other is carrying 2A, the neutral will be carrying 3A. Same 10A.

Understand?

 

[Speedy Petey]

And this is one of those instances where we should try to exceed and be better than the code book. Code may say it doesn't count but....why not do better?

Because WHY should you?? There is NO reason to. It creates more work and more cost unnecessarily.

 

[checkthisout]

Ok, so here is what I figured out:

With more than 4 NM's per "bundled" run or fire-stopped hole, you would be at 50% de-rating which means you would need to use a smaller breaker size than what is typically used for the wire gauge in the circuit. Bundling is when you run the wires together for more than 24". Running continuously through studs or under the same staple fits within the definition.

So,

4-6 conductors you de-rate to 80%

7-9 you de-rate 70%. 4 NM cables (including 12-3 and 14-3) = 8 current carrying conductors:

#14 wire=25 amps x .7 = 17.5 amps = 15 amp circuit breaker.

#12 wire=30 amps x .7 = 21 amps = 20 amp circuit breaker.


Did I do anything wrong here???

 

[Cmreschke]

Speedy I understand how it works, and in your last scenario, you are carrying current on your neutral because your load is not balanced. That current adds to increased heat in your bundle of conductors.

How much more work and cost to drill one extra hole?
2 minutes over the course of a day? With a hole hawg. In a wall so not just 1 hole but 1 hole per stud.
0 cost.

If we did everything g to just the code minimum, our installs would be the worst legally allowed. And sometimes exceeding the code book can be cheaper.

 

[Speedy Petey]

Speedy I understand how it works, and in your last scenario, you are carrying current on your neutral because your load is not balanced. That current adds to increased heat in your bundle of conductors.

NO, it does NOT, that's the thing. The third conductor DOES NOT add any more current. If you think there is added current and heat I honestly don't think you are getting my explanation.

How much more work and cost to drill one extra hole?
2 minutes over the course of a day? With a hole hawg. In a wall so not just 1 hole but 1 hole per stud.
0 cost.

Every scenario is different. Sometimes adding hold is an issue, sometimes it is not. When drilling is a royal PIA, like with the way guys frame today with lots of windows and openings, I'll keep it to as few holes as possible.

If we did everything g to just the code minimum, our installs would be the worst legally allowed. And sometimes exceeding the code book can be cheaper.

I never said I wire everything to code minimum, but of course I do some things. I'd never be competitive if I did not. None of us would.
I hardly think exceeding the code would ever be cheaper, but often it is a better solution.

 

[Speedy Petey]

Ok, so here is what I figured out:

With more than 4 NM's per "bundled" run or fire-stopped hole, you would be at 50% de-rating which means you would need to use a smaller breaker size than what is typically used for the wire gauge in the circuit. Bundling is when you run the wires together for more than 24". Running continuously through studs or under the same staple fits within the definition.

So,

4-6 conductors you de-rate to 80%

7-9 you de-rate 70%. 4 NM cables (including 12-3 and 14-3) = 8 current carrying conductors:

#14 wire=25 amps x .7 = 17.5 amps = 15 amp circuit breaker.

#12 wire=30 amps x .7 = 21 amps = 20 amp circuit breaker.


Did I do anything wrong here???

Nope. You get it just fine.