Rain Sensor ?

Discussion in 'Irrigation' started by JRAZ, Jun 12, 2005.

  1. JRAZ

    JRAZ LawnSite Member
    from NW
    Messages: 143

    I have a client that has an exisiting system and they would like a rain sensor installed. I haven't installed a sensor before but that seems easy enough. My problem is this, the clock is a 6 zone clock and all are wired to the 6 valves so there is not a terminal left for the hot wire to the sensor. My question is, can I piggy back a valve terminal with the sensor and will it work properly? Or am I way off here? How do y'all feel a bout sensors in general? Thanks!
  2. Jason Rose

    Jason Rose LawnSite Fanatic
    Messages: 5,858

    A hard wired type rain sensor (mini-click type for example) can be wired into your common wire. it interrupts the circuit when the disks in it get wet and expand. your controller will then still function as it would but the valves won't open because the common is open. This won't work, however, if your controller is running a pump thru a relay wired into the controller. If that's the case then the sensor would have to be wired to your 'sensor' connection on the controller. A wireless sensor will also have to be wired directly to the controller, then your 'sensor' can be placed within x feet of that.

    Most sensors work nice, but generally only stop watering during rain and maybe a day after, depending on sensor placement (sun or shade). Still better to have one than having people watering in the rain wasting that much more water.
  3. kerdog

    kerdog LawnSite Member
    Messages: 129

    Hey JRAZ-------

    You could go to Rainbird/Hunter web-site, and get some more info about how to wire sensors. Or whatever brand controller, or sensor, you are using, try that brands web-site.

    See ya----kerdog
  4. bicmudpuppy

    bicmudpuppy LawnSite Silver Member
    Messages: 2,781

    In general, I find rain sensors to be a complete waste. Just my opinion, but watering in the rain still happens until you've had enough rain to trip the sensor, and then they dry out about three times to fast. I wish they would install a rain delay program into the rain sensor circuit of some of the more modern clocks. If having a sensor trip would initiate a rain delay of a programed length, then we would have a useful device.

    As to wiring, you shouldn't have a problem, you don't need a station to connect the sensor to. All a rain sensor does is break a circuit. If there is a "sensor" terminal set, then the rain sensor breaks that circuit, if not, the sensor is wired in series w/ the common to break the common wire and prevent valve actuation. If you are connecting a sensor that needs power, you will take power from the tranformer or 24v posts directly, not from a valve station.

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