How to pick a ground wire out from others?

Discussion in 'Irrigation' started by advancedlawnsolutions, May 21, 2008.

  1. advancedlawnsolutions

    advancedlawnsolutions LawnSite Member
    Posts: 62

    Hey guys I've got a crazy situation. I got called to replace a clock on a 26 zone system. No big deal except somewhere through my extreme caution I still managed to get the wires crossed up on the last 9 zones, and they are all the same color. I've already spent soem time tyring to eliminate 1 by 1 but no success. I have a volage meter, but I'm not real sure how to find the ground wire(s) a couple of the wires must be a jumper ground for the expansion modules (hunter ICC). Any thoughts?:confused:
     
  2. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,014

    Rule #53 ~ If wires are identical colors, you flag them before you disconnect them. Now you get to flag them anyway, and take resistance measurements between them, and build a great big chart of your measurements. If the solenoids are identical, the common wire will show itself as the one wire with the low resistance to all the others.
     
  3. EagleLandscape

    EagleLandscape LawnSite Platinum Member
    Male, from Garland, Texas
    Posts: 4,347

    i think there is a deal called houndsomething that u can put on one end of the wire and go to the other end and itll beep when u id'ed the right wire.

    put this on the common at a valve, and see which wire it picks out back at the controller.
     
  4. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,014

    ....and while you're at the electrical supply house buying the fox-and-hound dealie, you can also get a set of marking tapes for the wires.

    [​IMG] ~ about two bucks
     
  5. CAPT Stream Rotar

    CAPT Stream Rotar LawnSite Fanatic
    Posts: 5,959



    boots, don't you need to have a common in order to get resistance readings?
     
  6. greenmonster304

    greenmonster304 LawnSite Gold Member
    Posts: 3,162

  7. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,014

    You can get a resistance reading between any pair of zone/common wires on a sprinkler system. Most of the readings will be double, because they run through two solenoids.
     
  8. CAPT Stream Rotar

    CAPT Stream Rotar LawnSite Fanatic
    Posts: 5,959

    oh, so when you get half of what the "norm reading" for that situation you have almost located the common..

    Example:

    you keep getting 48 48 48 48 48 48 48 48 48 24


    with that 24 you have narrowed down the common to a possibility of 2 wires...

    Right?
     
  9. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Posts: 48,014

    That's the idea. In a worst case, you have differing solenoids and multiple valves on a zone, so you have to take a lot of measurements. If this was a problem of 26 zones of identical valves, then you could isolate the common with less than thirty measurements.
     

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