Here's an update.

I got annoyed enough about my UPS shutting down with every little power blip (storm yesterday; lights flickered all day) that I wrote to APC tech support. These folks make the uninterruptible power supply I'm using.

I told them I have only the PC, monitor, router and cable modem on the battery backup. I asked APC why, if my equipment draws only 114 watts and their power supply supports 700, was it shutting down all the time instead of kicking in with battery backup?

They said that the Antec 500 watt power supply is designed with something called PFC, power factor corrected, and that it initially momentarily draws 1.25 time the rated power. That meant that a 500 watt power supply alone was drawing 625 watts. When you add in my monitor and modem and router, it pushed it over the 700 watts rating of my UPS.

Once I disconnected all but the PC, the UPS works fine.

Therefore, I can either buy a replacement UPS for more wattage, or get a second small one for my monitor and router and modem. Either way, APC is happy.

I'm amazed more people do not complain about this, though. The PFC power supplies are popular because they meet Energy Star requirements, which is something anyone would reasonably want to do if they could, but this design means that you need a MUCH bigger UPS that you otherwise would, to accommodate that initial surge.

BIAB 2025 Win Audiophile. Software: Studio One 7 Pro, Swam horns, Acoustica-7, Notion 6, Song Master Pro, Win 11 Home. Hardware: Intel i9, 32 Gb; Roland Integra-7, Presonus 192 & Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors.