Romex Vs THHN in condtioned area

Discussion in 'Electrical and Wiring' started by gottodo1, Aug 22, 2013.

  1. Aug 22, 2013 #1

    gottodo1

    gottodo1

    gottodo1

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    I moved to ND and opened up a wall today and I saw THHN used in the wall with no conduit. There's no THHN at the breaker panel so he must have spliced it somewhere? I found a forum that said you had to use THHN in a conduit even interior to a home because of section 300.3(a). I no longer have access to the NEC so I was wondering if someone could find that and put it on here.

    My next questions are, can you have THHN run into a break panel?
    To meet code, do you really have to use conduit on THHN interior to a house (in floor joists), for wiring to fans and outlets and the such?
    What possible reason is there to have conduit on the THHN when you don't on Romex?
    Is there any type of wrap on conduit that would satisfy the could I might be able to put on after the fact, maybe like a tape?? or maybe something like http://www.directindustry.com/prod/hellermanntyton-usa/corrugated-wiring-protective-conduits-31061-653667.html

    Does anyone know of a free site I could access the NEC?
     
    Last edited: Aug 22, 2013
  2. Aug 22, 2013 #2

    JoeD

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    Yes if you use conduit.
    Yes THHN must always be in conduit.
    It needs protection. NM cable has the outer jacket for protection.
    There is no wrap on system that will satisfy code.
     
    kok328 likes this.
  3. Aug 23, 2013 #3

    nealtw

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  4. Aug 23, 2013 #4

    kok328

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    I don't know that NEC access is free anywhere.
    It's also hard to pinpoint particular situations in plain English.
     
  5. Aug 23, 2013 #5

    bud16415

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    A Google search shows that the NFPA makes the NEC code available on line to “enhancing public safety” as they put it.

    http://www.electricalcodecoalition.org/free-nec-access.aspx

    http://www.nfpa.org/freeaccess

    http://www.nfpa.org/codes-and-standards/document-information-pages?mode=code&code=70

    I haven’t signed in or made a logon so I’m only going by what the web page says they have. If it is all on there and free let us know how it works out.

    Here is another source that has PDF files in bulk for download. It looks like it has the 2008 NEC the file is huge so will take some time to download.

    https://bulk.resource.org/codes.gov/
     
    Last edited: Aug 23, 2013
  6. Aug 23, 2013 #6

    bud16415

    bud16415

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    Ok I was bored and had some time on my hand and downloaded NEC 2008 from the bulk center. The file took about 15 minutes over a very fast connection to get 127M file size.

    Kok328 is correct it’s hard to “pinpoint particular situations in plain English” you asked about 300.3 A and this is what it says.

    Reading along I didn’t see any mention of combining wires to make a cable and most of the logic behind wanting cables was about keeping branches together. They do talk about white and gray being the colors of the combined cables. Hope this helps. I saved the PDF to my computer and it’s an easy access now.

    300.3 Conductors.
    (A) Single Conductors. Single conductors specified in
    Table 310. shall only be installed where part of a
    recognized wiring method of Chapter 3.
    Exception: Individual conductors shall be permitted where
    installed as separate overhead conductors in accordance
    with 225.6.
    (B) Conductors of the Same Circuit. All conductors of
    the same circuit and, where used, the grounded conductor
    and all equipment grounding conductors and bonding conductors
    shall be contained within the same raceway, auxiliary
    gutter, cable tray, cablebus assembly, trench, cable, or
    cord, unless otherwise permitted in accordance with
    300.3(B)(l) through (B)(4).
    (1) Paralleled Installations. Conductors shall be permitted
    to be run in parallel in accordance with the provisions
    of 31004. The requirement to run all circuit conductors
    within the same raceway, auxiliary gutter, cable tray,
    trench, cable, or cord shall apply separately to each portion
    of the paralleled installation, and the equipment grounding
    conductors shall comply with the provisions of 250.122.
    Parallel runs in cable tray shall comply with the provisions
    of 392.8(D).
     
  7. Aug 23, 2013 #7

    gottodo1

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    Was it to code to run THHN without conduit in 1996 or anytime in the 90's for that matter?

    Neal, Fortunately I don't live in Canada though darn close, so I don't think those books will help a whole lot.

    Joe D, thanks for the reply that's what I figured but I always like to ask dumb questions and see how many dumb answers I get.

    JoeD, THHN does have protection like romex with an outer jacket. THHN is almost always (and is in this case) THWN so it has an outer jacket to protect the inner jacket material. WHICH makes it superior to Romex because it's more rot resistant. I would think in a basement that would be a good thing?*

    Bud, thanks for the posting, that did answer what I was looking for and explains how he spliced it, but without conduit I doubt it's correct... Unfortunately for me back in 1996 either conduit wasn't required in housing with THHN cabling or the previous owner didn't care and just ran it the wrong way when he finished the basement. He ran an outlet outside to the garden so I'm assuming he bought 500' of it and then just decided to use it to finish his basement when he ran out of Romex... so sad.
     
    Last edited: Aug 23, 2013
  8. Aug 23, 2013 #8

    bud16415

    bud16415

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    I’m sure that happened also. Lots of people are finding a roll of wire at a garage sale or something left over etc. and using it up because wire is so expensive now.

    In my old house the #10 wire going to the garage (not attached) went underground from the house. It was single strand braded like your THHN and pulled thru a garden hose and buried. I’m pretty sure that didn’t meet code but it worked for many years.

    What you have is a modern version of knob and tube without the knobs and the tubes. If you don’t want it I think it would be easier to pull new than try and add the conduit.
     
  9. Aug 24, 2013 #9

    nealtw

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  10. Aug 24, 2013 #10

    JoeD

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    It was never code to run THHN without conduit except when knob and tube was allowed.
     
  11. Aug 24, 2013 #11

    gottodo1

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    Ya, didn't know what knob and tube was... good stuff there :). Looks like I'll be re-running today, at least as I make holes I'm not bothering to patch until I get everything done. My wife is getting a little sick of the extent of how much I'm "fixing" on this house from '89. Worst part is, it's not really broken but if it's not done right likely it eventually will be.
     

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