Water pump controllers - Question

[Ultima357]

The situation I'm trying to get to grips with is how a water pump controller will work with an irrigation system. Scenario is the garden (Mediterranean island) is irrigated currently by a manually switched pump, fed from an overhead storage tank. The tank is there because the water supply is very inconsistent during summer months, sometimes not being available for a few days at a time. So I'm looking to automate it using a standard pressure regulated and run dry pump controller and timing the irrigation via a suitable timer valve. 

 

I know if these controllers detect run dry, (eg tank empty and no mains feed), they switch off the pump to avoid damage which is good. Normally, the pump is in suction mode and in run dry detection, the controller has to be manually reset. (you press a reset button) But with the tank, when the mains water is restored, it'll have water fed to the controller with about 1m head of pressure. 

 

So the question is, in this case, would the 1m head of water reset the controller without manual intervention? 

 

As I understand it, the presence of water in the controller lifts a small magnetic float that switches in the electronics via a reed switch. Hence this query before spending circa £150 on bits to do this. The ultimate aim being to automate the irrigation to endure the garden gets watered without relying on a gardener to do it. But it needs to be foolproof and it will almost certainly encounter the run dry at some point like last year when the water was off for a week due to the failure of the mains water grid. 

 

[Conor]

Better off having a level sensor that switches the pump off before it runs dry. And you can have a similar for filling the tank from the mains supply, if desired. I'm sure there's also a way to use a shelly relay in the setup so you can have it timed remotely monitored and activated.