9fingers wrote:What is the tank material Roger? If non metallic then capacitative sensors might be an alternative worth looking into as you can stick them on the outside where you wish.
Bob
Brick ! It's the surround at the top of the well in the cellar. What happens is that the water table inside the well is higher than the floor and so water gradually weeps through cracks etc ((I think). Tanking not practical because the inside is always full of water and outside would look awful. So opting for the high tech solution.
I've got a relay but need to see what the coil voltage requirements are. That's for tomorrow. Omron LY2NJ. Hopefully it's 240v.
This is what I've come up with.
- (121.44 KiB)
Assumption is that when the water level reaches the float, the contacts close. Distance between the two floats needs to be small and so shortest float switch I think.
Operation...
Water at required level...Upper and Lower OPEN. Pump off
Water gradually rises and Lower CLOSES and feeds mains to Upper float and also latching contacts on relay. Pump off.
Water reaches 'bail out time' Upper CLOSES. Completing the circuit, relay energises and contacts C close thus latching the relay on. Pump ON.
Water gradually falls, Upper OPENS but relay still held on by the latching contacts.
Until water level falls below Lower which breaks the circuit.
If opportunity doesn't knock, build a door.