I want to build a circuit to switch a 1 1/2hp pump ON and OFF. ON to fill a large tank. OFF when the tank is full. I want to use a mechanical start (push the button) with a switch to cut the power. I see this as a mechanical latching relay application. I prefer to have a 24vac coil to match other devices in the system.
I want latching so that the coil is not powered during the 3 hour fill time but only gets momentary power when the full float completes the coil circuit. After that, the coil and the pump lose power until a finger pushes button.
The catalogs I have read suggest the mechanical portion of the relay is an accessory. How do I spec this relay? I know I need to have contacts for two hot legs to the pump and contacts to control the power to the step down transformer for the coil. I am a hobbyist. Thank you for any clues.