NMB (romex) in emt or wire mold

Status
Not open for further replies.

Mr 3phase

Member
I would appreciate any guidance on this matter... I am going to be doing a project where as I have to wire 5 smoke detectors together (2 in a front common hall, 2 in a rear common hall, one in the basement). The walls are concrete.
Therefore, I was going to use either wire mold or emt as a raceway, and strip the sheathing off the romex at the locations where it will be inside the raceway. At either end I would have only about 1 inch of sheating entering the raceways. If I use emt, I would have a transition at either end to secure the romex. If I use wire mold, I would essentially do the same thing. Thus the raceway is simply that, a raceway and the 'cable' of romex is reduced to four conductors (hot, neutral, ground and red wire is signal wire) in a raceway.
I am being told by a wiring inspector that this is a code violation because the wires are not THHN.
Where does it state than romex wires are not THHN, and this method cannot be used?
 

roger

Moderator
Staff member
Location
Fl
Occupation
Retired Electrician
I would appreciate any guidance on this matter... I am going to be doing a project where as I have to wire 5 smoke detectors together (2 in a front common hall, 2 in a rear common hall, one in the basement). The walls are concrete.
Therefore, I was going to use either wire mold or emt as a raceway, and strip the sheathing off the romex at the locations where it will be inside the raceway. At either end I would have only about 1 inch of sheating entering the raceways. If I use emt, I would have a transition at either end to secure the romex. If I use wire mold, I would essentially do the same thing. Thus the raceway is simply that, a raceway and the 'cable' of romex is reduced to four conductors (hot, neutral, ground and red wire is signal wire) in a raceway.
I am being told by a wiring inspector that this is a code violation because the wires are not THHN.
Where does it state than romex wires are not THHN, and this method cannot be used?

You do not have to strip off the NM sheathing, it is allowed in the racway as a cable assembly and the inspector is correct, you can not install these conductors without the sheathing, see 310.11

Roger
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
I was going to use either wire mold or emt as a raceway, and strip the sheathing off the romex at the locations where it will be inside the raceway. At either end I would have only about 1 inch of sheating entering the raceways.
I believe that is a violation.

334.15(C)Conduit or tubing shall be provided with a suitable insulating bushing or adapter at the point the cable enters the raceway. The NM cable sheath shall extend through the conduit or tubing and into the outlet or device box not less than 6 mm (? in.). The cable shall be secured within 300 mm (12 in.) of the point where the cable enters the conduit or tubing. Metal conduit, tubing, and metal outlet boxes shall be connected to an equipment grounding conductor.

Where does it state than romex wires are not THHN, and this method cannot be used?
Where does it state that romex is thhn? That being said why does the wire have to be thhn?
 

raider1

Senior Member
Staff member
Location
Logan, Utah
310.11 (2008 NEC) requires that conductors be marked with specific information. The conductors inside of the NM cable are not individually marked and violate this section.

Do not remove the sheath from the NM cable and just install the NM cable with the sheath intact inside of the EMT or Wiremold. It is not a violation to install NM cable in a raceway provided that the raceway is not in a wet location and you don;t exceed the conduit fill for the raceway.

Chris
 

Mr 3phase

Member
310.11 (2008 NEC) requires that conductors be marked with specific information. The conductors inside of the NM cable are not individually marked and violate this section.

Do not remove the sheath from the NM cable and just install the NM cable with the sheath intact inside of the EMT or Wiremold. It is not a violation to install NM cable in a raceway provided that the raceway is not in a wet location and you don;t exceed the conduit fill for the raceway.

Chris

When I mentioned this to the electrical inspector, he insisted that it was a code violation to install a cable in a raceway. Where does it say that in the code book because I cannot find it and that is the issue at hand, being told that I cannot do the project the way I planned to because I am told that I can't put the cable in a raceway.
 

raider1

Senior Member
Staff member
Location
Logan, Utah
When I mentioned this to the electrical inspector, he insisted that it was a code violation to install a cable in a raceway. Where does it say that in the code book because I cannot find it and that is the issue at hand, being told that I cannot do the project the way I planned to because I am told that I can't put the cable in a raceway.

Ask the inspector to cite the code section that prohibits installing NM cable in a raceway.

He won't be able to because there is no code section that prohibits it (Unless the raceway is in a damp or wet location).

Chris
 

tmason

Member
I would appreciate any guidance on this matter... I am going to be doing a project where as I have to wire 5 smoke detectors together (2 in a front common hall, 2 in a rear common hall, one in the basement). The walls are concrete.
Therefore, I was going to use either wire mold or emt as a raceway, and strip the sheathing off the romex at the locations where it will be inside the raceway. At either end I would have only about 1 inch of sheating entering the raceways. If I use emt, I would have a transition at either end to secure the romex. If I use wire mold, I would essentially do the same thing. Thus the raceway is simply that, a raceway and the 'cable' of romex is reduced to four conductors (hot, neutral, ground and red wire is signal wire) in a raceway.
I am being told by a wiring inspector that this is a code violation because the wires are not THHN.
Where does it state than romex wires are not THHN, and this method cannot be used?
What state is this
 

roger

Moderator
Staff member
Location
Fl
Occupation
Retired Electrician
When I mentioned this to the electrical inspector, he insisted that it was a code violation to install a cable in a raceway. Where does it say that in the code book because I cannot find it and that is the issue at hand, being told that I cannot do the project the way I planned to because I am told that I can't put the cable in a raceway.
Lookat any of the conduit or tubing xxx.22 article sections for example 358.22

358.22 Number of Conductors.
The number of conductors shall not exceed that permitted by the percentage fill specified in Table 1, Chapter 9.
Cables shall be permitted to be installed where such use is not prohibited by the respective cable articles. The number of cables shall not exceed the allowable percentage fill specified in Table 1, Chapter 9.
and article 334 doesn't prohibit it.

Roger
 

iwire

Moderator
Staff member
Location
Massachusetts
310.11 (2008 NEC) requires that conductors be marked with specific information. The conductors inside of the NM cable are not individually marked and violate this section.

So I can't strip NM for use in a raceway but I can strip NM in large enclosures.

Where can I find this distinction in the NEC? :grin::cool:
 

roger

Moderator
Staff member
Location
Fl
Occupation
Retired Electrician
So I can't strip NM for use in a raceway but I can strip NM in large enclosures.

Where can I find this distinction in the NEC? :grin::cool:

Nobody claimed you could terminate the NM. :grin:

Roger
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Here is what I do. I take the metal backing out of the wiremold and just use the wiremold as a sleeve or protection for the nm. I don't think the inspector can say anything about that. :grin:
 

iwire

Moderator
Staff member
Location
Massachusetts
I am not using the wiremold for what it is listed for so I doubt that it matters.

Actually it is a listed product so it has to be used as listed per 110.3(B).

Now that said, I use EMT for things that it is not listed for either so I am in no position to throw stones. :grin:
 
Status
Not open for further replies.
Top