My situation a little complicated as sometimes the system will be running off an old bore pump and sometimes will run off my mains supply (i.e. when away). Currently split into 6 zones + master. Pressure builds up quickly with the bore pump so need to be able to open up the valves for each zone all together ideally without any delay and with less chance of failure (I read system resets if not enough current?). The solenoids have a 0.4amp in rush current and a 0.2 amp holding. Is it just a case of buying a transformer that can handle all the current needs? Best I can find here in Australia is a 24V AC 3A transformer https://www.altronics.com.au/p/m6014-powertran-ip68-24v-ac-3a-appliance-transformer/ For the OpenSprinkler itself I have the version 3 AC model, with an expansion board and ethernet.
Edit: Thinking further the obvious solution I guess is open them all up before the bore gets turned on. Be still interested to know though if it’s limited by the transformer size or something else within OpenSprinkler and also about using a contactor