Hello,
I have a fun little project...
I have buried several water storage tanks in the ground at my property, living in AZ its hard to let good water go to waste!
So to retrieve the water, each tank has a 12V submersible pump at the bottom with a float switch. My intention is to have a circuit set up so that each tank will empty sequentially with one pump running at a time. Once a float switch signals a tank is empty, it shuts off its motor and the next motor in line is energized. The issue is, my limited circuit diagram knowledge has all the pumps running at the same time, which would still work, but exhaust the solar/battery capability too quickly... I was trying to design a system of relays to work it but became paralyzed and cross eyed! If you have ideas as to how I can improve the system please chime on in! Kindest Regards, Paul

 

You could use a current sense relay, such as a Hall effect device, to detect when the current stops in a pump and use that to turn on the next pump in sequence.
You would need one less relay than the number of pumps.

 

Easy enough if you've had enough coffee.

 

Easy enough if you've had enough coffee.

That requires access to the float switch output, which may not be easy if the float switch is part of the submersible pump.

 

What could be easier than splicing into float switch and installing a few relays......for a regular guy?
The tanks can't be that deep....shrinkable tubing can seal it.

 

What could be easier than splicing into float switch and installing a few relays......for a regular guy?
The tanks can't be that deep....shrinkable tubing can seal it.

But that won't seal where it comes out of the relay housing.
It would depend on how the float switch is sealed and how you connect to the switch wiring.

And what if your are an irregular guy?

 

You could also alternate the pumps......for equal run time. Is it necessary to completely empty one before another ....for some reason?

Edit: Depending on how you are filling the tanks....and depending on how you are emptying the tanks......A sequential strategy might put most of the work on one pump.

If you alternate the pumps......there is a good chance that the weakest pump will fail first.

With sequential...the best pump might fail first.

 

This is mere speculation starting at post #4. Better to wait for the T.S. to confirm or deny my assumptions...unless you enjoy speculating.