Micro810 wiring question

Hello all, time for my usual overthinking wiring post. Thank you in advanced.

Just got a Micro810 PLC. It has AC I/O I was confused how to hook it up. below is the schematic.


I guess my dilemma was to hook up the neutral or hot. Which after some good ole rtfm berating on reddit. It was obvious it doens’t matter. hook one up to the com then the other to the input.

My issue or confusion was the wiring diagram. Nothing said L2/N (3) was com for input nor in the manual.

When seeing this would you just assume (3) is com for the i/o?

I just connected pin 1 to live and pins 2 and 3 to neutral. Whenever the inputs saw 230Vac, they read high.

With a 240 VAC supply, there should be 2 hots and a neutral. Terminal 1 has to be a hot, but terminal’s 2 and 3 can be either the neutral or the second leg, so you could wire it L1, N, L2 or L1, L2, N; it doesn’t matter.

Edit: In the previous post, @deon.korb seems to be saying that you can also wire it with 120VAC by duplicating the neutral and it will work as well: L1, N, N

I live where we have 230Vac@50Hz single phase

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I see. Then you would have to land the L1, and then jumper the neutral: L1, N, N

Yes, that’s why it its marking includes the “/N”. The manual doesn’t mention isolation, so I would assume the two L2 terminals are internally connected.

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@pturmel I assume they are “bipolar” if thats even the correct term. But I guess I just had trouble assuming one was for com. vs both be for input voltage.

Just another day of over thinking. Thank you!

Yup. AC doesn’t have polarity. “N” for neutral simply means the phase that is bonded to ground. If neither is grounded, phase order doesn’t really matter.

Yeah I guess my bigger issue was that no where it said (3) was for comms. I’d assume (2) is not for comms. And originally assumed (3) was not for comms either because it didnt state it was. I guess they just assume its common sense. Something I clearly must not have. lol.