It would be interesting to see how you have your well/water system set up.
I only have one well which provides all household water. It was imperative then that I not interrupt regular water usage. I also needed whatever modifications I made to the system to be easily reversible as it would be under constant tinkering (I can't resist). And if there was some malfunction in my design or code (I am an amateur) and I was not home it needed a simple shut off point to return to stock operation.
Originally my well system was very simple well->check valve->pressure switch->pressure tank->house plumbing. I placed a T between the well and before the original pressure switch that runs PVC to the pond. This line has a
120VAC solenoid valve and a check valve.
I ran 120V to well house from my shop. There is an easily accessible switch that can disable all 120V to the well house. This is important as turning this switch off completely disable any mods I have made.
There is an AVR based circuit that is connected to a 4-20ma pressure transducer that monitors pressure in the house. It also controls the 120V via a small solid state relay.
The 120V is also connected to a mechanical
relay that controls the 240V to the well.
The mechanical relay and traditional pressure switch are wired in parallel.
1. I turn on 120V with switch in shop.
2. AVR program reads pressure transducer. If within acceptable range it will close the circuit on the 120VAC.
3. With the 120V circuit closed the solenoid valve opens allowing flow to the pond and the large relay closes turning on the well.
4. The AVR continuously monitors the pressure transducer.
5. Once the house PSI has fallen just
below the cut-on PSI of the pressure switch. The AVR disables the 120V closing the solenoid valve and the mechanical relay sending water to the pressure tank.
6. Once the house PSI has risen just
below the cut-off
pressure of the pressure switch it closes the 120V circuit again sending water back to the pond.
7. When the 120V is shut off with the switch the pressure switch takes over and the pressure tanks reaches full charge and the well is turned off.
Importantly because the 240V well switches are in parallel the well never shuts off. The household can use water just as normal as the house is always given priority. The ultimate test was turning the system on and not telling anybody -- nobody noticed.
I still need to tie this system into the rest of my automated house stuff especially the pond height monitoring system that I started this thread with.
