conduit question

[supratreo]

hi, quick question for you all. i'm running some NM form a in-wall panel, up through the ceiling and dropping it down about 30' away. only issue is that i have a huge header on that side so i'm not able to drop it in the wall, it would have to be through the ceiling and along the wall. this is all on the interior of the building. i've read that you can not run NM through conduit so what would i have to do to protect/enclose the wire, if anything? the wire will def. be safe from any damage but i would rather not have wire just exposed like that if possible.

thank you

 

[acer66]

Afaik NM in conduit is okay.

 

[Norcal]

If short sections of conduit are used to protect NM cable that is fine but to put the whole run in conduit is a huge pain in the azz.

 

[nadogail]

I built a wooden raceway to conceal and provide physical protection for the exposed NM in my garage.

 

[supratreo]

got it. thank you. it will be about 2-3' of straight conduit. wood would be more work than its worth i think. its only one cable.

 

[acer66]

Almost forgot, they make plastic bushings for the emt ends to protect the NM from getting damaged.

Halex 1/2 in. Electrical Metallic Tube (EMT) Insulating Bushing (4-Pack) 27501 - The Home Depot

Visit the Home Depot to buy Halex 1/2 in. EMT Insulating Bushings (4-Pack) 27501

www.homedepot.com

 

[BreeStephany]

Run the NMB in the enclosed space from the panel as far as you can, pop it through a romex clamp into the back of a 4 square surface mounted box, then switch over to THHN stranded conductors for the length of your conduit run, then switch back to NMB where it drops back into the wall.

Just my two cents.

 

[Innovate1]

Most places will accept just a runner board next to the NM as protection. No need to completely enclose. But conduit also works. With PVC just knock the sharp edge off the inside of the ends and no need for any other things.

 

[supratreo]

Almost forgot, they make plastic bushings for the emt ends to protect the NM from getting damaged.

Halex 1/2 in. Electrical Metallic Tube (EMT) Insulating Bushing (4-Pack) 27501 - The Home Depot

Visit the Home Depot to buy Halex 1/2 in. EMT Insulating Bushings (4-Pack) 27501

www.homedepot.com

i got a few of those ready but thank you for the reminder.

trying not to have to splice anything if i dont have to. wire will not be running back into the wall after it pops out of the ceiling.

 

[sparky 1971]

This is an official EMT to romex fitting.

Halex 1/2 in. Standard Fitting Electrical Metallic Tube (EMT) Combination Coupling 91530 - The Home Depot

The 1/2 in. Combination Coupling is used to couple EMT conduit with non-metal conduit. This combination coupling is made of zinc, is intended for indoor use. This is UL- and cULus listed.

www.homedepot.com

I hate those effing things though. I just use an EMT set screw coupling. They have a nice round edge so if the romex does wind up against it, nothing bad will happen.

Halex 1/2 in. Standard Fitting Electrical Metallic Tube (EMT) Set-Screw Coupling (5-Pack) 23220 - The Home Depot

The 1/2 in. EMT Set-Screw Coupling is UL and CSA Listed for safety and can be used for indoor and outdoor applications. This standard fitting is made of zinc, is for use with EMT conduit and comes with

www.homedepot.com

 

[mike93lx]

If short sections of conduit are used to protect NM cable that is fine but to put the whole run in conduit is a huge pain in the azz.

A pain in the ***, but compliant to do.

 

[Norcal]

A pain in the ***, but compliant to do.

Did not say it was not, just a PITA.

 

[mike93lx]

Did not say it was not, just a PITA.

You said it was OK if it was a short run. I was just clarifying for others that it is code compliant regardless of length. That part didn't seem clear

 

[Innovate1]

I see a lot of replies are assuming metal conduit. I was thinking of PVC. No end fittings or clamps to worry about. I didn't see the OP state what kind of conduit he was thinking of using.

 

[supratreo]

thank you for the replies. type of conduit doesnt really matter. i was thinking EMT but i think i have some 1" pvc laying around do i'll probably just use that. would i still need a bushing or can i just knock off the sharp inside edge?

 

[mike93lx]

thank you for the replies. type of conduit doesnt really matter. i was thinking EMT but i think i have some 1" pvc laying around do i'll probably just use that. would i still need a bushing or can i just knock off the sharp inside edge?

You need a bushing or something that provides the same protection, like a box adapter.

I use bushings for all conduit installs so there is no debate if I should have used one or not

 

[supratreo]

great. thank you.

 

[Innovate1]

You need a bushing or something that provides the same protection, like a box adapter.

Like knocking the sharp edge off the inside edge of the PVC cut end. It seems to me this is something the local AHJ may interpret differently so if this is being inspected probably safest to ask or use a bushing or box adapter but practically it seems unnecessary.

 

[nh_yota]

You can definitely run NM in conduit - as long as it's in a dry location. I think a lot of the "can't run NM In conduit" confusion comes from the fact that you can't run NM in conduit in a wet location. Conduit doesn't magically change a wet location into a dry location.

 

[mike93lx]

Like knocking the sharp edge off the inside edge of the PVC cut end. It seems to me this is something the local AHJ may interpret differently so if this is being inspected probably safest to ask or use a bushing or box adapter but practically it seems unnecessary.

No argument there. It's a PIA to add one after, so I just put one in at the beginning.

 

[yatg]

For PVC, I use a coupler. Looks better.

 

[supratreo]

i wasn't aware of the wet vs dry usage. from what i've read its more if a heat dissipation issue. stating that NM needs to be in "free air" to dissipate heat as its wrapped so tight where loose wire in conduit has plenty of room. this is just from what i've read here, seems logical tho.

 

[sparky 1971]

i wasn't aware of the wet vs dry usage. from what i've read its more if a heat dissipation issue. stating that NM needs to be in "free air" to dissipate heat as its wrapped so tight where loose wire in conduit has plenty of room. this is just from what i've read here, seems logical tho.

The heat issue is taken care of by treating NM as TW using the 60° column of 310,16 even though the conductors have 90° (THHN) insulation.

 

[wyliesdiesels]

i wasn't aware of the wet vs dry usage. from what i've read its more if a heat dissipation issue. stating that NM needs to be in "free air" to dissipate heat as its wrapped so tight where loose wire in conduit has plenty of room. this is just from what i've read here, seems logical tho.

yeah no such issue