I live in a small community at the end of a long line in Atlantic Canada. We get frequent power disruptions so I have installed a backup generator. I have a bit of a home lab, and don’t like my server to lose power with no warning so I’ve recently installed a small UPS to keep it running in the gap between my power going out and the generator starting. The UPS logs data and lets me access it.

I’m wondering if I should be concerned about my input voltage. The blue line in the minimum for the hour, the amber is maximum for the hour. The zero period on the 8th of March was when I had the power turned off to do some work.

The default configuration for my UPS has it cut over to battery power at 88V, so it seems some significant variation is expected!

I tried searching my power company web site but they don’t seem to publish anything about guaranteed, or even expected, supply voltage.