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UPS SYSTEM HELP
(alien.top)
650w is a lot, and looking at the manual for your UPS I think you're exceeding the limits. It even explains what a long beep means. RTFM, as they say.
Rack mounted replacements are fun. I got a used APC which works well. I bought replacement batteries for it, so make sure you budget for that. Mine uses 4 of these https://www.osibatteries.com/vision-cp1290-battery-12v-9ah-sealed-rechargeable
Batteries are bad. Can be replaced, but getting into a rackmount UPS is nice too.
What model and configuration are both of your servers?