I want to switch a 0.33 kW 415VAC three phase motor and also monitor the individual phases. (Yes, I know the dangers - to myself but not necessarily to the Arduino with low voltage inductive spikes etc. I frequently work with 415VAC 3 phase.)
I thought that I could use this setup for each phase with the three respective signal pins connected to the one arduino output pin.
Would this work? With the three control circuits coming into the one signal pin, could there be a crosstalk or any other issues?
Secondly, I would like to stop the motor if one of the phases dropped out through loss of power or failure of one of the triacs. How could I safely monitor the voltage on each phase? I do not want to use relays.