Page 2 of 2 FirstFirst 12
Results 11 to 14 of 14

Thread: Anyone have a link to insulation codes (XHHW, TW, RH, THHN etc)

  1. #11
    Join Date
    Feb 2008
    Location
    Indiana
    Posts
    265
    Quote Originally Posted by zbang
    I think you have to consider some letters as two-letter codes, for instance MT/MC/MI, since M could be either metal or machine. Also that a letter might have one meaning in the first position and others later in the code.

    S- I've always heard that as "Stage", it's not silicone.
    J- Junior (thinner insulation)
    O- Oil reisitant
    OO- Really oil resistant
    A- Asbestos
    I was thinking S was silicone as in SRML - Silicone Rubber Motor Lead

  2. #12
    Join Date
    Feb 2008
    Location
    Houston
    Posts
    662

    Building Wire and Cable Designations


  3. #13
    Join Date
    Feb 2008
    Location
    Indiana
    Posts
    265
    Quote Originally Posted by Chamuit
    That gets a lot of them. Thanks for the link. Here's a cut and paste from the link:

    Building Wire and Cable Designations


    by Technical Support


    Technical Information & Technical Bulletins



    THW-2: Thermoplastic Insulation (usually PVC), Heat Resistant (90°C rating), suitable for Wet locations.



    THWN-2: Same as THW except Nylon jacket over reduced insulation thickness. Also rated THHN.



    THHN: Thermoplastic Insulation (usually PVC), High Heat Resistant (90°C rating), dry locations only, Nylon jacket. Also rated THWN.



    TFFN: Thermoplastic Insulation (usually PVC), Flexible Fixture wire, Nylon jacket. Also rated MTW and AWM.



    TFN: Thermoplastic Insulation (usually PVC), Fixture wire, Nylon jacket. Also rated AWM.



    XHHW-2: Cross-linked Polyethylene Insulation (X) High Heat Resistant (90°C rating) for Wet and dry locations.



    RHH: Rubber Insulation (we actually use cross-linked polyethylene because it qualifies for rubber), High Heat Resistant (90°C rating) for dry locations only.



    RHW-2: Rubber Insulation (again, cross-linked polyethylene is used by most manufacturers), Heat Resistant (90°C), Suitable for Wet locations.



    USE-2: Underground Service Entrance. Most utilize cross-linked polyethylene insulation rated for 90°C in direct burial applications. Product is usually triple rated RHH—RHW—2-USE-2.



    MTW: Machine Tool Wire. Usually thermoplastic insulation (PVC) or thermoplastic insulation with nylon jacket. Most MTW is rated 60°C. Southwire's copper type THHN is also rated MTW.



    AWM: Appliance Wiring Material. Usually thermoplastic insulation (PVC) or thermoplastic insulation with nylon jacket. Southwire's stranded copper type THHN in AWG sizes 14 through 6 is also rated AWM. As AWM, the product carries a 105°C rating.



    NM-B: Nonmetallic-Sheathed Cable. The "B" denotes that individual conductor insulation is rated 90°C; however, ampacity is limited to that for a 60°C conductor (see NEC Section 336-26, 1999 edition). Thermoplastic (PVC) conductor insulation-nylon jacketed, with overall PVC cable jacket.



    UF-B: Undergound Feeder. The "B" denotes that individual conductor insulation is rated 90°C; however, ampacity is limited to that for a 60°C conductor (see NEC Section 339-3(a)(4), 1999 edition.) Thermoplastic (PVC) conductor insulation-nylon jacketed, with overall PVC cable jacket.



    SEU: Service Entrance Cable, Unarmored. Usually type XHHW insulated conductors with overall PVC jacket. As such, the cable is rated for 90°C dry, 75°C wet locations. Another school of thought is the "U" in the designation denotes the shape of the cable (if you look at the end, it resembles a closed "U" shape).



    SER: Service Entrance Cable, Round. Same construction material-wise as SEU, but round construction affords use of more than 3 conductors to which SEU is limited.

  4. #14
    Join Date
    Jun 2006
    Location
    Ohio
    Posts
    12,653
    Quote Originally Posted by C3PO
    I believe you can find that in the UL marking guides also.
    http://www.ul.com/regulators/W&CMG_April2007_Final.pdf

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •