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Thread: NMB (romex) in emt or wire mold

  1. #1

    NMB (romex) in emt or wire mold

    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?

  2. #2
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    Quote Originally Posted by Mr 3phase View Post
    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
    Moderator

  3. #3
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    Quote Originally Posted by Mr 3phase View Post
    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 (ΒΌ 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?

  4. #4
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    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

  5. #5
    Quote Originally Posted by raider1 View Post
    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.

  6. #6
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    Quote Originally Posted by Mr 3phase View Post
    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

  7. #7
    Join Date
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    Quote Originally Posted by Mr 3phase View Post
    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

  8. #8
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    Quote Originally Posted by Mr 3phase View Post
    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
    Moderator

  9. #9
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    Quote Originally Posted by tmason View Post
    What state is this
    Tmason welcome to the forums.

    Do you know of a state that has amended this part of the NEC?

    Roger
    Moderator

  10. #10
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    Quote Originally Posted by raider1 View Post
    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:

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