3-phase board 3 voltages and the BluePill

[Robert.Wall]

@dave-in-nj

And it appears that it would be best to measure line voltage (phase to neutral), not phase to phase voltage.

I’d agree with that. If you have a balanced resistive load, the line current is in phase with the L-N voltage, so there’s no need for a 60° phase shift in the software.

@dave-in-nj

One of the questions that keeps nagging in my head is to have a separate voltage only board and use the ZMPT101B transformers so as to have one board with the high voltages be separate from the current sensing board.

I would certainly go down that route. It makes testing on live circuits so much safer. And I’d steer well clear of the modules that have a built-in multiplier resistor - it’s much preferred to use two equal resistors in series, then if one fails to a short, or flashes over, you stand a chance with the remaining one.

And cut a slot in the board underneath the transformer to give you a decent creepage distance between the high and low voltage sides.