Water wicking down control wire

Discussion in 'Irrigation' started by bobw, Mar 18, 2009.

  1. bobw

    bobw LawnSite Senior Member
    Messages: 807

    Interesting situation I've got to figure out. I have a commercial site where the controller is installed 30 feet below grade. The control wire (multi-strand) exits the building 3 feet below grade. The valve box that the control wire goes to is in an area that has some serious ground moisture issues.

    So...here is the problem... the ground water is getting into the control wire between the wires and the sheathing and wicking down into the controller in a small drip.

    Any one dealt with this before? Any ideas on solution?

    The only thing I have thought of so far is to smear caulking over the cable where we've cut the sheathing back for wire access and stop the water from entering the cable.

    I don't want to replace the cable itself because a) I don't want to have to deal with recoring and waterproofing the concrete wall and b) this isn't a fault in the cable per se, more a ground water issue.
  2. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,764

    Simple solution is to add more wire, so the drips can fall off the low point of the wiring, and not drain into the controller. Let someone else deal with the waterproofing.
  3. bobw

    bobw LawnSite Senior Member
    Messages: 807

    The drips aren't on the outside...they are between the strands and the outer sheathing.

    Besides...that's a pretty tacky solution :D
  4. DanaMac

    DanaMac LawnSite Fanatic
    Messages: 13,226

    How much extra slack is there for the multistrand in the valve box? This may seem weird, but workable if there is enough slack. Unhook the wiring in the manifold, pull wire outside of the box, pull up above ground and install conduit around multistrand, and feed into an above ground junction box. Then run another section of multistrand from the j-box to the valve box and manifold. Wire the sections in j-box together.

    Just a thought.
  5. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,764

    Did you install the wiring? It isn't your problem until you stand to make a good profit by its solution.
  6. bobw

    bobw LawnSite Senior Member
    Messages: 807

    Wow..we must be in the depth's of winter...nobody wants to work!

    I did indeed install the wiring; I'd like to get my contract holdback paid out, so I am quite motivated to solve the problem

    Dana - I can't see an above ground junction box working out. This is right beside a sidewalk in a office building.
  7. DanaMac

    DanaMac LawnSite Fanatic
    Messages: 13,226

    Well then you're screwed. :laugh:

    Try the caulking method then. Create a junction where the wires enter the building. Install in the most waterproof j-box you can get.
  8. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,764

    Then stop exiting foundations below grade, and rewire with an above-grade exit. You could spend forever dinking around with caulks and compression fittings.

    If I had to give it my one best shot at a below-grade repair, I put a pipe nipple around the wire, and use hydraulic cement to seal it to the foundation. Then you thread a special cap onto the nipple. A split gland, or single piece of rubber, provides the seal, as you tighten the cap. Electrical supply houses have this stuff.
    Last edited: Mar 18, 2009
  9. irritation

    irritation LawnSite Gold Member
    Messages: 3,594

    Use heat shrink tubing where the wires meet the insulation.
  10. AI Inc

    AI Inc LawnSite Fanatic
    Messages: 27,060

    Boots is correct, see if ya can pull more wire thru and create "drip loop" Or replace the wire

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