IOT based Smart Irrigation project

[mrnams]

Hello All,
I am working on IOT based Smart Irrigation project.
In first phase I shall work on controlling water pump, right now my 7.5hp motor is controlled by "3 phase star delta starter".
Could you please provide/point to web source for following queries?

1) Three phase motor don't have neutral, So how I get 5v dc to operate Arduino/ESP32 using 3phase 440volt?
2) How to measure voltage in each phase to protect motor from phase failure?
3) How to measure current very accurate to protect motor from dry run? which CT is best?
4) How to get status of motor whether its on or off?

 

[Kurenai_ryu]

1) get your own power supply (440V to 5VDC), most of them are isolated so you can ground them wherever you want
2) isolation transformers, but for phase failure there are some sensors specific for 3 phases
3) which is best? the best one you can afford do you plan to measure it yourself? maybe something that can be read by the esp32 ADC (look for those 100A to 100mA or similar ,low current /low voltage output)
4) if the current is under the specifications, everything is running ok, or just add a relay at the output to signal the on/off status