Pre Rough Inspection Questions?

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Old 09-05-15, 05:56 PM
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Pre Rough Inspection Questions?

I'm back again...

Before I cut my wires short and begin making up my boxes for the rough inspection I'm looking for some answers to a few specific questions.

1. Picture #1 below has an single gang box seated\nailed in-between two studs. There is not enough room to staple within 8" directly under the box. Is how I've stapled it with the staple being on the other side OK?



2. Picture #2 below shows how some of my wires go diagnostically between studs, is this OK? Picture #2 also shows how my electrical traverses behind my DWV plumbing is this OK?



3. Picture #3 in addition to the cubic inches table below shows what I believe to be the correctly calculated cubic inch requirement for my 5x #12/2 w/G and 2x receptacles. The box I have purchased is 34.6 cubic inches. Did I do the math right? There is going to be at least one pig tail in the box because of how I need pig tail the power-in to both the vanity light switch and the shower light dimmer. From what I've read wire nuts and pig tails do not contribute towards the cubic inch requirement.




 
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Old 09-06-15, 07:14 AM
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1) Drill your hole through the stud lower. Then you will be able to come up from below the box and staple within 8". The inspector might let it go except for your bending radius is pretty tight going through the hole.

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2) The cable routing is all ok in picture #2. One thing I will point out is you should not run the cable into the hole of the boxes closest to the stud. Inspectors in my area will flag that for sure. It brings the cable too close to the nailing face of the stud. It is OK to run more then one cable in a hold of a plastic box. The exception might be the two gang because of the spacer 2x.

3) My calculations are the same as yours except for the rounding up. I got 33.75 CI

Lastly most inspectors are going to want to see everything made up in the boxes. That means cable jacket stripped off, and all the splices made up.
 
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Old 09-06-15, 07:58 AM
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My experience differs, in that the knockout closest to the studs are allowed. The back of the box is too close to the face of the stud too, but there are no options.

Except for the grounds not being made up, I didn't see any concerns.
 
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Old 09-06-15, 08:00 AM
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Two cables under a clamp in a multigang box is not accepted. Two cables into a single knockout in a single gang box is fine. The difference is the clamping.
 
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Old 09-06-15, 12:35 PM
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Tolyn Ironhand & pcboss, thanks for the replies.

Concerning the cable bending radius, perhaps the photo below will help show that the bend is not too extreme. If you still think it is let me know.



Concerning the cables entering the knockout closest to the stud, I'll fix this but I can't find any info saying it's required. Not arguing, I just like to know for sure.

Concerning two cables within a single staple prior to entering a 2 gang box; I can't find any info on this. This is an easy fix so I'll probably just fix it. Do I simply staple them individually side by side? My worry is that if I do that then the wires\staples will come to close to the face of the stud. Thoughts?



Concerning the boxes not yet being made up, I understand this requirement.
 
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Old 09-06-15, 12:54 PM
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You can use a Stack-it as the clamping method at the box also. It doesn't have to be stapled.
 
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Old 09-06-15, 12:56 PM
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Two cables under the staple are fine, if the staple is listed that way. Many are.

For the 4 cables side by side I use the stacker like you have elsewhere. They keep the clearance required.

Regards to the knockout, that must be a local interpretation.
 
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Old 09-06-15, 01:05 PM
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The two cables per clamp PCboss was referring to was the clamps inside the two gang box, not the staples. The staples are listed for two 12/2 or two 14/2 cables so you are ok there. All the clamps I have used for NM cables, whether in a box or one that I install, are listed for at least two cables. Again, this might be a local thing in different parts of the US but our inspectors are OK with it.

My experience differs, in that the knockout closest to the studs are allowed. The back of the box is too close to the face of the stud too, but there are no options.
This could also be a local thing. The option on a "normal" box is to use the outside holes. 300.4(D)(2011) says conductors, cables, and raceways shall be protected by physical damage by keeping them 1 1/4" away from the face of the stud. It says nothing about boxes. Rather then rerouting the cables the code allows the use of nail plates to protect the cable(s) similar to what you already have.

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Old 09-06-15, 01:53 PM
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Thanks everyone for the input. My last question is below in the first pic along with some updated pics of the other things. Hope it's OK I post a lot of pics, I find them helpful when reviewing other people's posts.







 
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Old 09-06-15, 04:06 PM
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I would say the clamps need to be intact, but could also say that if secured within 8" of the box it would be the same as a singe gang box in concept.
 
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Old 09-06-15, 04:12 PM
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Just as an aside..... in residential wiring I like to wire all my lighting in #14 wiring to keep the clutter down in the switch boxes.
 
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Old 09-07-15, 06:47 AM
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Box Size

The box I have purchased is 34.6 cubic inches.
Is this volume stamped on the box or is it your calculated number? Seems like an odd dimension. You must use the volume stamped inside the box.
 
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Old 09-07-15, 08:02 AM
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@Wirepuller38,
Is this volume stamped on the box or is it your calculated number?
Stamped. Ha, I'm just now seeing the box also has the number of #12s I can use. Their count matches up with mine.


@PJmax,
I like to wire all my lighting in #14
Agreed, next time. #12 is making this box a bit tight.

@pcboss,
I would say the clamps need to be intact
I'll probably replace it, ~$1.25 fix.
 
 

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