Remote control of water pump

[Jurassicsparky]

Hi, I'm designing a wireless switching system for a cattle water trough. I'm looking for a float switch which would send a wireless signal to a receiver 300m away next to the pump and bring the pump on when required. There is line of sight between the units. At the moment the pump is switched manually but the farmer would like more control. Any suggestions?

 

[plugsandsparks]

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[brianmoooore]

What's wrong with a pressure switch controlling the pump, at the pump site and a ball valve in the cattle trough?
Water level drops, ball valve opens, pressure in pipe drops to zero, pump turns on. Trough fills, ball valve closes, pressure in pipe rises, pressure switch turns off pump.

 

[Jurassicsparky]

What's wrong with a pressure switch controlling the pump, at the pump site and a ball valve in the cattle trough?
Water level drops, ball valve opens, pressure in pipe drops to zero, pump turns on. Trough fills, ball valve closes, pressure in pipe rises, pressure switch turns off pump.

Thanks for that Brian. As an electrician I automatically thought of an electrical solution. I'll discuss it further with the client.

 

[brianmoooore]

That's the advantage of being both a sparky and a plumber, and living on a farm.
Note that the ball valve will need to WELL protected from the cattle, preferably in an enclosed compartment where they can't get at it.
An improvement to the system is to add a pressure vessel near the pump. It will prevent the pump switching on and off over short intervals.

 

[Lucien Nunes]

Brian's suggestion is a good one but I would say it is important to check what type of pump is in use before converting to a pressure system. The presence of the ball valve will increase the head it has to deliver and the frequency of starts it has to make. Some pumps are designed for that duty, others will be subject to greater wear.

Agree with Brian that an accumulator will probably be needed, both to prevent rapid cycling of the pump as the valve closes, and also to prevent water hammer if the valve, water column in the pipe and pressure switch attempt to oscillate. A pressure switch with adjustable differential is useful here.

I have an even more radical solution for you: If the pipe run is free of sharp bends, can you blow a thin submersible cable through it for the float switch?

 

[brianmoooore]

Cows are herd animals, and as such, they will ignore the trough for hours on end until one decides to have a drink. At that point, the whole lot will decide that they're thirsty and pile in, fighting and jostling for space at the trough.
The speed that five or six muzzles can lower the water level is impressive, so it's important to replenish the trough as fast as possible..
I'd suggest a low pressure ball valve to help with this - a 3/4" type if possible. This valve won't be capable of stopping the water flow on its own, because of the difference in dynamic and static pressure at the trough, but will increase the line pressure enough to trigger a pressure switch.