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.
88v would be well in the territory of a brownout, but according to that graph you are sitting comfortably within 10% of 115v, with one exception. This isn’t bad, if you viewed the graph with the y axis range set from 0v-140v it would look nearly flat. I wouldn’t worry about it, the UPS will handle the small transient stuff.
You can usually adjust the sensitivity of the UPS, but the power supplies should be able to handle a broad range of input - to a degree at the expense of their longevity. It all runs in DC. If the UPS supplies more power, the battery will die slightly more quickly, but the battery will die pretty quickly anyways.
The best method is to measure voltage near the watt hour meter.
Maybe your home installation isn’t good enough, like overloaded, too thin wires, etc.Not sure how mains is distributed in the Canada. Too many users on the same transformer?
Do you have a second phase?
The UPS is connected to an outlet that is about 1 metre from the electrical breaker panel. It’s a new house so the wiring should be OK. There are only 4 buildings/services on my local transformer so I think we’re stressing that. I have not checked the other phase and other comments have suggested that the variation I’m seeing is within normal range, so I probably won’t.
the Y axis is unreadable, so it’s impossible to say whether this is within normal bounds.
But 110-130 is totally fine, and universal power supplies (marked 100-250 VAC) will probably work down to at least 90V
