Can romex condcutors be installed in emt?

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Mr 3phase

Member
Is there any code or UL restriction prohibiting installing romex conductors in emt without the exterior sheathing?
 

iwire

Moderator
Staff member
Location
Massachusetts
Yes you can install NM in EMT see 358.22

Some feel the sheath has to stay on to comply with 300.11 which requires the conductors to be identified.

You can never run NM in a conduit in a wet location. see 300.9


(2008 NEC)
 

LEO2854

Esteemed Member
Location
Ma
Is there any code or UL restriction prohibiting installing romex conductors in emt without the exterior sheathing?

George do you meen striping off the the outer sheath?

Also Look at 334.15 (B)

You don't have to strip off the outer Sheathing:)
 

Mr 3phase

Member
I have 5 circuits, 4 of which are 12/2, and one is 14/2. The circuits go from the attic, down a pipe chase, to the basement, which has a finished ceiling. I want to install the romex (after stripping the sheathing off) in 3/4 emt, and run it back to the panel.
 

chris kennedy

Senior Member
Location
Miami Fla.
Occupation
60 yr old tool twisting electrician
I have 5 circuits, 4 of which are 12/2, and one is 14/2. The circuits go from the attic, down a pipe chase, to the basement, which has a finished ceiling. I want to install the romex (after stripping the sheathing off) in 3/4 emt, and run it back to the panel.

Sounds like this will create a derating issue.
 

Mr 3phase

Member
The code allows fifteen # 12 conductors in 3/4 emt. I will have 8, plus two #14 conductors . All grounds count as 1 . Thus 15 conductors total.
 

LEO2854

Esteemed Member
Location
Ma
I have 5 circuits, 4 of which are 12/2, and one is 14/2. The circuits go from the attic, down a pipe chase, to the basement, which has a finished ceiling. I want to install the romex (after stripping the sheathing off) in 3/4 emt, and run it back to the panel.

If you have 5 circuits then you should use two raceways:)
 

chris kennedy

Senior Member
Location
Miami Fla.
Occupation
60 yr old tool twisting electrician
You have 10 CCC's. T 310.15(B)(2)(a) tells us the conductors need to be derated by 50%. There for your 12's will need 15A OCPD's and your 14's 12?A breakers.:grin:
 

Mr 3phase

Member
You are correct. I will need to install 2 raceways of 1/2" emt in order to maintain the conductor rating. Or, cut holes in the ceiling, bust out one of the bricks on top of the carrier beam between the floor joists and run the wire betwen the joists and back to the panel that way. Then patch holes.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
You are correct. I will need to install 2 raceways of 1/2" emt in order to maintain the conductor rating. Or, cut holes in the ceiling, bust out one of the bricks on top of the carrier beam between the floor joists and run the wire betwen the joists and back to the panel that way. Then patch holes.

Just install a junction box at the top and pull in THHN. Use MWBC's so the neutrals do not count towards derating.
 

Mr 3phase

Member
The circuits are all to dedicated receptacles for a/c's. This is an old house, real old. I will just have to cut the ceiling open and run the wires back through the floor joists.
 

LEO2854

Esteemed Member
Location
Ma
The circuits are all to dedicated receptacles for a/c's. This is an old house, real old. I will just have to cut the ceiling open and run the wires back through the floor joists.

Can you run two pipes across the ceiling strait to the panel?
 

Mr 3phase

Member
Yes, I cant run two pipes. Here is the dilemna (sort of). The ceiling is old horsehair plaster and lathe. There is a carrier beam going right to left. There is fire blocking (bricks) in between the floor joists on top of the carrier beam. The 'easiest' way would have been to run pipe and thhn. However, there are 6 dedciated circuits. 5 of them are 12/2. One is 14/2. I installed the 12/2 for a/c units to be plugged in.
If I use pipe, I will need 3 runs. Two for the 12/2 and 1 for the 14/2. Either way, it's a pain in the butt.
 
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