Radio Linked Tank Float Switches?

mcnutt13579mcnutt13579 Registered Users Posts: 86 ✭✭✭
Customer has 4000 gallon water tank on hill. Well is right next to house. System is pure gravity, no pressure tank at all.

Well pump runs whenever generator runs. Generator runs only when commanded by inverter. Water tank runs dry if there is too much sun, and overflows down the ditch if the generator runs a lot.

I would like to install some sort of tri-level float system in these tanks. One float near the bottom that starts the generator whenever the tank gets too low. Another float near the middle that stops the generator if the bottom float is the one that started it. One float at the top that lets the well pump run and fill the tanks completely whenever it was the inverter that commanded it on.

The catch is that there is no easy possibility of installing a wire to these tanks. They are very far away and the pipe without wire was installed many decades ago through some rough country. Automation was not thought of back then. I want to do it by some radio link but it has to be reliable. I realize I will need a small panel and battery at the tank. The radio path should be pretty much line of sight so at least that should be no problem.

Is there such an animal ready-made?


  • jonrjonr Solar Expert Posts: 1,188 ✭✭✭✭
    Re: Radio Linked Tank Float Switches?

    How about this for a rather wild possibility: turn the pump and any usage off and then measure the pressure. If you can measure it accurately enough, you can determine the height in the tank.
  • kilewilliskilewillis Registered Users Posts: 4
    did you ever come up with a radio/ wireless control ?
  • mcnutt13579mcnutt13579 Registered Users Posts: 86 ✭✭✭
    We did a lot of research and never really found something industrial-grade enough that we thought it could be trusted.

    Have done several jobs with lots of sweat and difficulty that involved pulling new wires to tanks, etc. but once that is done you know no radio will ever lose its link or have another battery and solar panel to maintain.

    Still on the hunt for the right solution but it also takes the right customer and the right job.  ($$$$)

  • Marc KurthMarc Kurth Solar Expert Posts: 448 ✭✭✭✭
    it has been many years since I was involved with this, but yes, remote RF based pump/tank controls are common. We did several systems with 50,000 to 100,000 gallon tanks located remote from the pumps. These were large ranches and small municipal water systems where reliability and repeatability were critical. Some were better than others when you exceeded 1/2 mile. Even the lower cost systems worked well for shorter hauls. The longest range we did was 4.5 miles and we had to use Yagi's at both ends for the UHF link.

    Ours were set up with a standard two float, High/Low control. A quick Google check found several companies offering RF based remote control for pump/tank/irrigation system links.

    Jonr made a good suggestion, if you have a decent vertical differential at the tank. It would be easy to layout some relay/timer logic to sample the head pressure to accurately determine water column height. Highly accurate transducers don't cost as much as they used to, but if the tank is low will likely get very expensive for the transducer.


    I always have more questions than answers. That's the nature of life.
  • mcnutt13579mcnutt13579 Registered Users Posts: 86 ✭✭✭
    Can you specify a couple of float switch state transmitters you would recommend? 

    There is no shortage of people that say they make what we want, but experience has taught me what to think of that....
  • kilewilliskilewillis Registered Users Posts: 4
    I am looking into possible using this controller

    and looks like you have to buy the monitor/ lcd screen

    looks like it runs about $541 usd. only problem is I have to put a battery at the pump controller so it stays in contact with the lcd screen thingamajig

  • mcnutt13579mcnutt13579 Registered Users Posts: 86 ✭✭✭
    Doesn't meet the requirements I laid out, no dual level switching.

    We have been installing these to take advantage of opportunity loads.

    Also being from NZ, the frequency band will probably be wrong here in the US.
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