Connect with us

pulling large wire through PVC

Discussion in 'Electrical Engineering' started by Guest, Jan 16, 2008.

Scroll to continue with content
  1. Guest

    Guest Guest

    I need to pull 3 lengths of 2/0 copper THHN through about 270 ft of 2 inch
    PVC conduit with two 90 and two 45 bends in it. I've done this before, but
    always with three separate lengths of wire pulled together. My supplier
    says they may be able to get triplex wire cheaper than three separate wires.
    Is the triplex going to be harder, easier or about the same effort to pull
    as three separate wires pulled together?

    How feasible would it be to pull 3 lengths of 4/0 aluminium wire through
    this conduit? It's code-legal, but is it doable? Three 2/0 wires is the
    biggest load I've tried through this length of 2 inch PVC, and that was
    hard.

    I was talking with an electrician friend recently, and he mentioned that
    heavy pulling with nylon or poly rope can saw through bends of PVC conduit.
    I've always used nylon or polyester rope with no problems. My friend
    recommends cotton rope. Is this worth doing? Cotton is a lot weaker than
    nylon or polyester, which is a worry, plus I'd have to go buy it.

    Mike
     
  2. Dean Hoffman

    Dean Hoffman Guest

    I guess some people use steel elbows for this. A code class
    instructor mentioned that the steel had to be grounded at one time even
    if it was underground. Someone got electrocuted while doing repair
    work because the steel elbow wasn't grounded. Code writers not familiar
    with the history of the requirement later deleted the grounding provision.

    Dean
     
  3. bud--

    bud-- Guest

    I believe metal elbows in a PVC run have to be grounded unless buried
    below 18 inches, or a concrete requirement for non-service wires (NEC
    250.80-ex, 250.86-ex3).

    Damaging effect of the rope should depend partly on the rope diameter.
    Soft nylon is probably less abrasive than polyester.

    I wonder about the effect on triplex pulling it around a bend. The path
    around the outside of the bend is longer and the wires can't easily slip
    past each other to adjust. And with separate wires the 'longer' wire
    tends to stay the same wire.

    If you need more answers than you get on this newsgroup you could try
    posting on alt.home.repair which has several electricians.
     
  4. Guest

    On Wed, 16 Jan 2008 19:29:55 GMT wrote:

    | I need to pull 3 lengths of 2/0 copper THHN through about 270 ft of 2 inch
    | PVC conduit with two 90 and two 45 bends in it. I've done this before, but
    | always with three separate lengths of wire pulled together. My supplier
    | says they may be able to get triplex wire cheaper than three separate wires.
    | Is the triplex going to be harder, easier or about the same effort to pull
    | as three separate wires pulled together?

    My guess is the triplex will be slightly easier because you will not
    have as many points where separate wires are contacting the edges.
    When the triplex is rubbing on one side of the inside of the conduit,
    it is pulling the other wires with it and they will thus not rub on
    the other side at that point. OTOH, triplex may not as easily like
    to bend going around those conduit bends.

    BTW, what is the radius of the four bends?
     
  5. Guest

    Guest Guest

    Thanks for all the replies. Particularly for info on jam ratios and mule
    tape. I'll either use 3 2/0 copper wires, 2/0 copper triplex, or 4/0
    aluminum triplex (hope to avoid the latter, but $ may dictate it), and pull
    with mule tape.

    Mike
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-