OpenSprinkler Forums Hardware Questions OpenSprinkler Pi (OSPi) Ok to hardwire 7 zones (7 x 24V AC valves in parallel) with OSPI? Reply To: Ok to hardwire 7 zones (7 x 24V AC valves in parallel) with OSPI?

#78710

nachtigall
Participant

> Well you can always write a script yourself and send command to OpenSprinkler to open zones in any pattern you’d like. A single firmware is not going to fit everyone’s need. The reason we make the whole product open-source is to give users the freedom of modify the software in any way they want.

OpenSprinkler, also its API, is really great. And I am very happy and grateful for being able to use it.

> Also, the firmware supports up to 40 programs, so technically you can create many programs to define when does each group of zones start. So in theory you can use multiple programs to do anything you want. It is certainly tedious and difficult to update this group of programs, but it should be able to achieve what you need.

This is what we do currently. But the 7 Driplines run 1h each, that is, 7h alltogether. Our water pump is rather loud and also takes 800 W. By wiring all together the driplines can run in 1h together.

> If you want to hardwire multiple zones to the same port, please note that a single port can support no more than 2 parallel solenoids. Each solenoid draws 250 to 300mA holding current, and 500 to 700mA impulse current. The triac on each zone cannot drive more than 800mA to 1Amp max, so it can’t do more than 2 zones. You can always use an external relay, which can drive amps or even tens of amps. That way one single zone switches the relay, and the relay in turn switches high current load.

As said, I am not good in electronics. I have a software developer background. The power adapter I have from https://opensprinklershop.de/product/netzteil-24vac-15a-36va/ says:

> Kann bis zu 8 Zonen gleichzeitig bedienen! Siehe unten verlinktes Video!
(English: Can operate/run up to 8 zones simultaneously! See the video linked below!)

This is just for the OSPI. For the PI itself a have a designated USB-C power adapter extra (2A I think).

Also I hardwired the 7 zones today and it seems to be working. So I am a bit confused now whether it is ok or not as you said that at most 2 can be hardwired.

Kind regards, Jens