On Thu, Mar 2, 2023 at 9:42 PM Tim via users <users@xxxxxxxxxxxxxxxxxxxxxxx> wrote: > > I have a UPS sitting next to me, right now, in pieces, which (half) > died in a most peculiar manner: > > A burning smell was eventually traced to it. There's no visible signs > of burning, and no schematic available for the model, that I can find. > A rather acrid smell, not one I'm used to with component failure, I'm > beginning to suspect a large AC transformer. > > While running off the mains its output is a (too) low voltage, but > still high enough for most switch-mode power supplies to run normally > (i.e. the computer and monitor). It has some kind of AC voltage > regulation built into it to deal with under and over-voltage. The > AC supply was normal, at the time. > > But running off its battery it produces the full 240 volts it's > supposed to. > If you read about normal UPSes they are not normally designed to run 100% duty cycle (ie on battery for days, or fixing up a low voltage for days). So if you run yours at say 40% load it will probably survive under the higher duty cycle, but if you run it close to 100% load and it gets into cleaning up low voltages the UPS electronics may not survive long (ie if fixing the voltages for hours/days). So if they end up running in that state for long periods of time (either because of adding bigger batteries--my UPS came with 12AH batterys but now has external 35AH ones) and/or extended low voltages various components may burn out. There is also a setting on at least some UPSes that you can change so that it does not regulate the lower voltages (wider acceptable voltage range) and accepts those voltages as ok. I have done that with both of my UPSes because the default setting prevents the UPSes from charging when on a small generator, and would if the voltages was low but still good enough cause the UPS to keep fixing the slightly low voltages and possibly burn out. _______________________________________________ users mailing list -- users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to users-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@xxxxxxxxxxxxxxxxxxxxxxx Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
