Voltage in the grid

[73hunter]

So…there have been threads here in the past about running generators when the power is out, and how various people are set up, and some mentions about the dangers of running modern electronics from generators where voltage and frequency may not be consistent. Ive often wondered what sort of variation these modern electronics will handle.

back in the ice storm this spring we were running the genny and I was checking voltage while various items were cycling on and off, and found that our microwave on its own caused our 3000W generator to drop to 110V. So based on earlier reading I was careful not to run the furnace while anything else was on. I had also got to thinking that there must be some plug-in device that would display the voltage in the outlet so that I didn’t have to use my multimeter prongs constantly. Found a 2 - pack of these on Amazon and keep them on in the garage now.

the grid normally runs between 124V and 127V….and in a few recent hot days as everyone’s AC runs nearly constant..it’s often down between 110-113V. Lowest reading I’ve observed has been 107V today.

[Fisherman]

It's not only the voltage fluctuation with a generator but the frequency, most household items from furnaces to egg beaters, (anything with a motor) like to have a freq of 59-61 Hz. Electronic items such as TV's, computers like to be closer to the 60Hz than others. Items that only produce heat like toasters, incandescent lights aren't as susceptible. In fact, any power with a frequency as little as one per cent above or below the standard 50Hz risks damaging equipment and infrastructure if it persists, this also goes for the north american 60Hz. Just checked mine it's fluctuating between 113-114 volts with no a/c running