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Digital Timer for Fimco Hydro-Indexing Valve

Discussion in 'Irrigation' started by anotherbrian, May 31, 2011.

  1. anotherbrian

    anotherbrian LawnSite Member
    Messages: 21

    I talked with the tech folks at a irrigation timer manufacturer and it is possible to use a digital timer with the Hydro-Indexing valve. I assume the same applies for other digital timer manufactures.

    Here is how it is done, at least for the one manufacturer. The timer is wired to single electric valve as a single zone. The timer allows multiple programs to be run. So two programs are used, program A and program B. Within each program there can be up to 4 start times. Thus, program A is used with 3 start times and program B is similarly programed with 3 start times. (This assumes the indexing valve controls 6 zones).

    The advantage of digital are as follows:

    a) The length of watering time is more manageable. My existing timer is programmed (if that is a correct term) in multiples of 12 minutes. With the digital I can program it to any multiple of minutes. This translates into real $ for folks on city water.

    b) Less likelihood of getting city code watering violations. In my area, irrigation is only permitted on certain times and days of the week. The electro mechanical clock occasionally needs to be reset due to the frequent power outages we experience in this area. When the time drifts due to the power outages, irrigation occurs outside of the allotted time. During dry times the city gets aggressive, although I have never gotten a fine I have gotten warnings.

    c) Optimal timing for watering. When the electro mechancal timer drifts due to power outages, the irrigation events occur outside of the optimal late night / early morning hours.

    d) Safety. My particular electro mechanical timer provides 110V to the solenoid. With the digital, a safer 24V is used.

    Assuming that I can get the desired amount of water in 18 minutes per zone, then I should be able to reduce my water consumption by 25%. (The mechanical timer would require two 12 minute periods whereas the digital would require 18 minutes. Thus the savings is 25% = (24-18)/24.

    Actual savings will depend on the individual irrigation system itself and time of year. (e.g., perhaps your system provides adequate watering in 20 minutes which means your savings would be 12.5%.)

    I post this because I others asking this question on other sites.
  2. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,592

    It doesn't quite work that way. You need a controller with an adjustable delay between zones, like a Hunter Pro-C, and the feed valve to the indexer is connected to the master-valve terminal. Only a single start time is required for a complete watering cycle. The delay between zones is essential because an index valve takes time to advance to its next position.
  3. anotherbrian

    anotherbrian LawnSite Member
    Messages: 21

    Your correct to bring up the issue.

    I may have misunderstood the tech but I believe he said that there is always a 5 minute delay between start up times, and so the issue was covered by that manufacturer.
  4. anotherbrian

    anotherbrian LawnSite Member
    Messages: 21

    I found the pro-c works fine with my fimco. The instematic has a feature that allows one to move from zone to zone by toggling an switch. The pro-c has an equivalent function which is just as easy to use. The pro-c is rich with features.

    It is not possible to set up the timer for seasonal changes (e.g.,winter watering schedule and summer watering schedule). The indexing valve is viewed as a single zone from the timer's perspective. So it takes two programs, each started three times, to get the fimco to walk through all of its 6 zones. So there are not enough programs to make a winter/summer schedule.
  5. jvanvliet

    jvanvliet LawnSite Gold Member
    Messages: 3,944

    Boots is right, only a single start time is required with a valve delay of about one minute between zones (with an AVB between the master valve valve & the Fimco). If the master valve is a pump, I'd set the valve delay to about five minutes so as not to put too much undue stress on the pump motor from cycling too quickly.

    A valve delay is a common feature available on Hunter Pro C, Rainbird ESP series and maybe some big box cheapies.

    You won't get out from under loosing your watering cycle on the indexing valve since any interruption in flow will cycle the the valve to the next zone. The battery back up will only save the time and programming.

    If accurately timing each zone is an issue (usually it is) change to an all electric valve system and trash the Fimco. Most residential down here is on an indexing valve as well as some commercial, they are a PIA to manage.
  6. anotherbrian

    anotherbrian LawnSite Member
    Messages: 21

    When using the valvie delay capability, is the solenoid wired as a single pro-c zone? Or do you hard wire 6 of the pro-c terminals to the single solenoid?

    T1 --------soledoid


  7. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,592

    None of the zones get wired to anything, (see note below) because only the master valve terminal is connected.

    * if an open zone circuit gives you an error message and a zone shutdown, then you would have to find a substitute electrical load to 'fool' the controller - or, you can go back to the idea of wiring all the 'used' zones together and feeding the valve from there
  8. jvanvliet

    jvanvliet LawnSite Gold Member
    Messages: 3,944

    See what Boots said. you only need to wire the master valve and program the delay. If you need to "fool" the controller, replace it. A Rainbird ESM is only about $80.00.
  9. Wet_Boots

    Wet_Boots LawnSite Fanatic
    Messages: 50,592

    How many current controller models gag on an open circuit? Outside of a error message to point at a possible problem, I wouldn't think you'd ever want the controller to shut down on an open circuit.
  10. jvanvliet

    jvanvliet LawnSite Gold Member
    Messages: 3,944

    Of course you would.

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