can 24vac operate 2 valves?

Discussion in 'Irrigation' started by zliminator, Mar 1, 2007.

  1. zliminator

    zliminator LawnSite Member
    Messages: 82

    I have a zone in the middle of a circular driveway that wasn't working. I cut the wires and cycled threw the zones and found voltage going to the valve when zone 4 was operating. (there was another valve for zone 4 because I saw another zone come on). So I figured it was a bad valve. After replacing the valve and reconnecting the wires, I found the valve not working when zone 4 came on. Oh crap, did I install a non-working valve? I cut the wires and got a separate 24v transformer and the valve worked perfectly. So now I'm thinking that since the timer only has 8 zones and this on should have been zone 9, that the original designer "doubled up" 2 valves on 1 zone and there's just not enough "umph" from the timer box. (I did see the new valve come on for just a second when zone 4 was calling). I also noticed the pressure to zone 4 go way down when zone 4 was calling and I manually opened the new valve. There is a cable which goes beside the pipe under the circle driveway which I'm going to cut into. My only hope is that I can double up on another zone which doesn't have as many heads and not loose pressure. I could put another box with more than 8 zones, but there's no way to get the wires to the valve under the driveway. (There probably wasn't anything wrong with the valve I replaced).

  2. aric43085

    aric43085 LawnSite Member
    from Ohio
    Messages: 71

    Most new controllers will support up to three valves (including master valve). What type of controller and valve are you using?
  3. zliminator

    zliminator LawnSite Member
    Messages: 82

  4. bicmudpuppy

    bicmudpuppy LawnSite Silver Member
    Messages: 2,781

    That my friend is some serious pipe art. If you haven't burried that hole, fix the 3/4" reducer connection on the lateral. After having disturbed the soil around it, that joint is going to give way sometime in the near future. Replace the tee and use a 45 to get to line up the 3/4 line. Depending on the model of controller, you should have no problem firing two valves at once in your situation. You stated you had voltage when #4 runs, how much voltage? The point where this wire and zone 4 combine may be a bad splice.
  5. PurpHaze

    PurpHaze LawnSite Fanatic
    Messages: 5,496

    As ARIC stated: Most newer types of controllers will fire multiple zones that are wired together. Just make sure that the zones are the same types of sprinklers or you'll have a major unbalanced precipitation problem.

    On some of our large athletic field systems architects will double up two 2" valves on the same station number instead of installing a 3" valve and making the main laterals larger. This seems to be quite prevalent with LAs for some reason and there's good and bad aspects to it. The good is that if one valve goes out then only half of a zone is affected. The bad is that we have more wire and valves in the ground where something can go wrong.

    As BRYAN stated: A good irrigation piping system is a lot lot a good wine and needs some breathing room. I've never been keen on installers that double back lateral lines through a valve box area.
  6. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,905

    Rainscape East
  7. Dirty Water

    Dirty Water LawnSite Fanatic
    Messages: 6,794

    And you guys got on my case last time I knocked Florida Irrigation.

    That valve would have been replaced as last resort, and any good irrigation troubleshooter would know that.

    Your burning your clients money.
  8. SprinklerGuy

    SprinklerGuy LawnSite Bronze Member
    Messages: 1,778

    Ut oh..............
  9. zliminator

    zliminator LawnSite Member
    Messages: 82

    I measured 26 volts.

  10. bicmudpuppy

    bicmudpuppy LawnSite Silver Member
    Messages: 2,781

    If you've got 26 volts, your solenoid should fire. If you put the solenoid back in the circuit, what voltage do you get? Try it again with a new, know good solenoid. IF the voltage drops down with the solenoid in circuit, I still think your chasing a ground fault or bad splice (bad splice would still be a fault). I would guess the drop to be down to around 8-10volts. time to locate the entire wire path, and a pulsar would be the easy way. Pot holing between the last known good point in the wire you can find and the valve would be the next step. I would find and check the wiring/splices at each valve between the controller and the non-working spot first.

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