I am rebuilding my sprinkler system after my dumb Orbit controller died. I have three zones controlled by the standard irrigation valves that operate on 24vac. I was going to build my own simple controller using an ESP32 board, but also thinking about using Shelly 1 relays. I am trying to figure out how to control the 24vac solenoids that open and close the valves. I just don’t know if a 12v relay can switch a 24vac load. Will a Shelly 1 relay be able to pass 24vac in detached switch mode? Any other advice or options that I’m not thinking about? Thanks
A 12v relay generally refers to the voltage required by the coil to switch the contacts. It has nothing to do with how much voltage it can switch, that is another specification.
Also you want a relay with a 3.3v coil if you are using an ESP board. That’s what logic level comes out of the GPIO. All the commonly available 3.3v relay modules made for Arduino boards and the like will be able to switch 24v AC and will be able to switch your solenoid valves. e.g.