I should start with the disclaimer that I have no particular expertise with NUT so this guide is not definitive.
I have a Cyberpower UPS (CP685AVR) powering a Raspberry Pi and my Unraid Server.
Initially I installed apcupsd on the Pi, connected it to the UPS (via USB) and setup Unraid as slave. Install was fairly straightforward and worked well except for automatic restart after shutdown - when power's restored connected servers must be booted manually. (NOTE: If your Cyb