This CyberPower news article says: higher end workstations and computer systems that incorporate Active Power Factor Correction (PFC) power supplies may unexpectedly shut down or crash entirely when used with a simulated sine wave UPS. CyberPower use the term, PFC Sinewave, and APC (APC 1500VA/900W UPS ) uses the term Sinewave UPS.
I just received a new Eaton UPS (Eaton 3S 700). I plugged it to a wall socket and connected a small tower server, a switch and a router. They work fine. My problem: the UPS is beeping continuously ...
Download the APC UPS Daemon command line tool and use it to disabled the APC Back-UPS 550 alarm. Note: This advice is based on software that was last updated in 2016 and I recommended in another answer back in 2020. I know I have successfully used it on macOS back in the “OS X” days in the past but haven’t in years. So hopefully this will work for you.
The VA rating tells you about the maximum load you can put on the UPS, and this can also be a very loose proxy for the quality of the components - because higher rated UPS's will typically have componentry and cooling which can support higher currents and are thus more robust.
Why are UPS battery backups all rated in VA instead of AH?
If a UPS lasts long enough, the cost of replacement batteries overruns the initial cost. If you are buying quality UPSes, therefore, give more consideration to the running cost of the UPS than to the initial purchase price.⁶ A midrange UPS from the same manufacturer costs about ⅓ that of a true-sine UPS with the same headline specs.