So I chose the Shelly pro 1 pm for 3 reasons.
1. The capabilities of being turned off via WiFi, what I want to make is a completely remote setup, where I can activate, print and disable my printer from school.
2. The function of power monitoring, because I will build some vorons for my school and I need to find out the cost to power the printer per year (1 month times 12).
3. The Ethernet port, because the printer is connected via Ethernet and WiFi in basement is bad, so the Shelly should also use Ethernet.
The cable you marked is from the main power switch, next to the motor with also the blue coming out and those 4 pins like things.
This is the live wire for the whole system, so Like the live wire from the your wall, but for Saftey reason I still pass the wall power through that switch(where the live you marks comes from) So I can turn off everything for sure when working on printer ( i still unplug cable).
Also tested the wiring in my printer yesterday with the schematics above (without the separate switch box, will implement ones it prints) and the connection via wifi worked (could turn on and off) and there was nothing shorted, today I can also test if power consumption will work. Because printer is still being upgraded with other parts.
In general thanks for your help, in the beginning didn’t understand wiring at all but now I do a bit better, I will not close this thread/post yet because I am unsure if power monitoring will work.