Using emt as raceway to protect nm-b

[anythingyoucanimagine]

I have some places where stud spacing is not standard 16oc like rest of home. I passed rough before I realized that the f'n framers fucked with a future homeowner (only 4 places I found trash in the stud cavities happen to be only 4 places where stud spacing is off and a royal pain in the balls).


Aren't there plastic end caps made for ent so you can transition nm-b into ent, then back out, or into a box?


Internet folk lore says all kinds of things about putting nm-b into emt. Essentially I want to use it as a big nail plate. These are all less than 48" sections and far enough away from boxes that securing the nm-b isn't an issue.


I have four locations I'm not comfortable with. If I can't run nm-b through ent (edit: I said eNt, I meant eMt) for protection I'll buy some mild steel U-channel, drill holes in it for attachment to studs and notch it for nm-b staples, then run that in strips.

 

[sberry]

Got to protect it. You can do that especially for 1 cable.

 

[alfredeneuman]

One of these https://www.homedepot.com/p/Carlon-1-in-ENT-Male-Adapter-Case-of-10-A243F-CAR/202690631 (they should be available in different sizes)
a rigid conduit coupling, and an EMT connector.

 

[anythingyoucanimagine]

Thank you both. So should I call inspector or just do it? Is this one of those nec compliant "beg for forgiveness" situations? If so I may need a wink or a nudge...

 

[acer66]

Aren't there plastic end caps made for ent so you can transition nm-b into ent, then back out, or into a box?

They are called insulating bushings and you only need them where the nm exits the emt,
at the box you use the regular emt to box connector.

 

[alfredeneuman]

It shouldn't be but I can't guarantee it.
Transitions directly from ENT to EMT are available too but good luck finding one those; they're likely rarer then hen's teeth.

 

[alfredeneuman]

They are called insulating bushings and you only need them where the nm exits the emt,

But, if there is any space between the 2 raceways, won't that expose the NM to the physical damage he's trying to protect it from?

 

[acer66]

But, if there is any space between the 2 raceways, won't that expose the NM to the physical damage he's trying to protect it from?

Yes, you are right, my bad.

 

[alfredeneuman]

Well you do have a point. He wants to use the EMT for protection because the ENT is not suitable for protection, as is the case for NM.
The EMT will undoubtedly start before the point where it's required, so it doesn't make any difference.

 

[checkthisout]

You have to protect the EMT passing through studs in the same way you would have protect bare cable.

 

[anythingyoucanimagine]

Sorry for any confusion. I edited my initial post. There was one place where I said "use eNt as a giant nail plate" and I meant eMt.

Was asking about using a 36" section of metal conduit inside a wall, along a stud, basically as a big nail plate. So the nm would come out of the box then into a nm>>conduit bushing/fitting, then run the nm through 36" of metal pipe, then back out another fitting/bushing and up through the top plate.

I can't explain it and a picture would be useless. It's just a spot where I added a convenience light switch on the other side of the wall, it's a short section and when you measure over from one door frame king/jack & first stud, it seems normal but then the back side is F'd up just enough that if you found a stud then measured over assuming 16"oc, the stud is off by just enough that you could easily hit the wire trying to drill a pilot hole, etc.


In hindsight I should have paid more attention. Maybe I could have put the light switch on the other side of the stud or maybe bore a hole and run it up a different stud bay... idk. Too late now. It's done. I have a 31" section of 3/4 metal conduit with one nm 14/3 in it. Drywall is up so too late.

 

[mm08822]

May be easier to use this on one end of the conduit and a steel box on the other end assuming you now have plastic.

 

[Alxhastngs]

In hindsight I should have paid more attention. Maybe I could have put the light switch on the other side of the stud or maybe bore a hole and run it up a different stud bay... idk. Too late now. It's done. I have a 31" section of 3/4 metal conduit with one nm 14/3 in it. Drywall is up so too late.

Code wise I believe you are more than ok depending on the distance between studs. NM needs to be secured within 12 inches of the box, so unless your box was in the center of a stud cavity greater than 24" on center, your good.

The EMT you ran is really probably overkill to protect the wires, but as long as you used the correct bushings to secure the NM and prevent chaffing, your in a good place!