I’ve been running a Cyber Power 1325va pure sine wave UPS to power my PC, SO3 and SuperPID/router since nearly the beginning of my CNC adventures, about 14 months now (I added the SuperPID later in the adventure, but have had the UPS since almost the start). My vacuum I run straight off the wall, it just draws too many amps. I’ve never had a “disconnect” per se, although a week or so ago Carbide Motion 4 crashed about 3/4 of the way through the job(I mean the Windows program crashed), and I’ve had the issue where CM4 stops doing anything when I manually jog forward/up for a tool change between gcode programs that others have reported (router not running). I’ve actually had a power failure during a job and everything kept running (except for my vacuum), and the clocks in my house reset, haha!!! I’ve also purposely unplugged my machine while running an “air cut” without issue. I’ve read and re-read where motors and UPS don’t play well, but I’ve yet to see the issue with mine. Maybe I’m the lucky one, who knows? The big thing for me is if power dies, everything should die with it, you wouldn’t want your SO3 dragging a bit around without the router spinning, and you don’t want your router spinning in one spot of the SO3 dies and nothing is holding the router in place (friction, fire, bad things). I don’t run any super special USB cable, ferrite cores, none of it, I think my current cable came with my machine? In my old house I had one electrical outlet in my garage that would trip every time I held my head sideways, so I needed to do something if I wanted to play CNC. New house I have 2 dedicated 20 amp garage circuits. During my research for a UPS I remember that “pure sine wave” rather than “simulated” was the way to go, but it’s been awhile so I don’t remember the exact reason, do some research. My experience has been good, I can’t say that it’ll be the same for everyone.
p.s. make sure whatever you use can handle the amperage of whatever you’re powering + some head room. No point of buying a really tiny UPS just to have it shut down due to over loading. Also, I don’t use mine to keep the power running for a long time if I lose power, it’s used as a way to pause my job, shut stuff down, so I can resume once power returns without losing my spot (Yes, I sit next to my machine the whole time it’s running).