I have a Champion 100520 8750/7000w portable generator, it will power my entire home including the AC and my server rack as long as I am careful.
This post will detail the issues I had running my UPS directly plugged into the UPS.
I usually just use my generator interlock kit so backfeed my entire electrical panel.
I got it all setup today to plug my UPS directly into the generator, as tomorrow I am having some electrical work done which means I can't use my interlock kit.
As soon as I plugged my UPS into the generator, it tripped the GFCI. The 240v outlet that I usually use to backfeed the panel has no GFCI, so this was never a concern.
This is somewhat expected, but never in my life have I actually seen it take place - https://www.apc.com/us/en/faqs/FA369034/
In many places I've seen UPS's happily running on a GFCI Breaker. Perhaps this GFCI is lower quality? Perhaps an APC SRT3000RMXLA which takes a 30a input is not expecting to be on GFCI? Unsure. (Yes, I am now feeding my 30a UPS from a 20a outlet. But the total load is well under 20a, so it's fine.)
Without going to Home Depot and getting the hardware needed to convert the L14-30 outlet into a box that I can install some NEMA 5-15 outlets into, I was out of luck.
I ended up opening the front panel of the generator, and I saw that while the outlets looked a little different, they seemed to have the same screwhole spacing as a regular outlet, and on the front they were just Decora .
Here you can see a rough install, and it fits fine.
I did have to remove the tab for the bottom to clear the other things on the panel, but this is fine
The terminals attached no problem, and it fits perfectly. I had to use a 7mm socket to get the outlet removed, and re-installed
I plugged the UPS in, and it worked great! No problems
I will keep it like this, as during an emergency you don't want to find out something you are powering does not like the GFCI. Also GFCI outlets do go bad over time, so at least now I will always have a 120v output even if the other goes bad.
Looking at the old GFCI, it feels very cheap. And its dated 2012... Its now 2021. That's almost 10 years ago! I wonder what's going on with that.
Hopefully you read this before needing to power a UPS from your generator, only to find you can't
Thanks for reading
Here is a sneak peak of the "electrical work" I was having done. It will be detailed in a post soon