I knew got that from somewhere, but I'm ready to believe anything.
I wish i still had my oscope. I should shop for another some day.
My computer systems all have pure sine wave UPS's that clean/condition the power before passing it into the servers.
You should. If you really want to understand this stuff. Playing with a scope is how I finally wrapped my head around single phase, 3 phase, and "how many degrees out of phase."
(Assuming an isolated scope) put one probe across L1 and L2 of of a 3phase supply, observe sine wave. Put 2nd probe across L2 & L3, observe 2nd sine wave, 120 degrees out of phase from the first. Put 3rd probe across L3 & L1, observe 3rd sine wave, 120 degrees ahead of L2-L3 and 120 degrees behind L1-L2. 3 phases. 120 degrees out of phase from each other.
Now approach a single phase supply. Place probe across L1-L2, observe sine wave. Now take second probe and put it... where? Across L2-L1? That's silly. It's obviously the same thing as L1-L2, but reversed! There's only one phase. And it isn't any amount of degrees from anything, because there's no other phases to reference it against. Sure, you can reference to ground/neutral, but that's not a phase, it's a center tap of the one (single) phase of supply. It's a mind trap. Ground/neutral doesn't count.
There is such thing as "two phase" but it's very rare and consists of 4 wires. Unless you live in a 100+ y/o industrial facility in some isolated part of Michigan, youve never seen it and probably never will. It's two separate single phase supplies, 90 degrees out of phase from each other.
So why all these phases and degrees? Imagine riding a bicycle with only one leg. You tape your one foot to the pedal, and as long as someone gives you a push to get started, you can can keep going. That's single phase, and that's why single phase motors (mostly) require starting capacitors - the push from behind to get them started. Now imagine you have 3 legs and 3 pedals. Never mind the absurdity or the breach of physics, you could take off from any position of the pedals or the legs any time of day or night, covid or not. That's why 3 phase motors are better. One of the reasons. The 197 machines in Michigan using 2-phase power can do the same. They're a dude with 2 legs on a bike with 2 pedals, but their pedals are 90 degrees apart. So they can ride, but it's goofy and unnatural looking, and that's why the idea didn't spread outside of a few little isolated pockets of early industry.
Know that you do not have 2 phase.
Know that you have single phase with 2 legs and a neutral. For the bike analogy you can consider the neutral a crotch or a knee i suppose. Maybe an ankle.
Know that your single phase is not any amount of degrees out of phase with anything, and speaking of degrees is a waste of breath.
Know that your best bet is a single phase generator, but if you can't find that, look into a 12-wire 3 phase generator. Most of the time with those you can wire them for single phase with a derating factor.
Most importantly, Know that your method of turning off your main supply breaker and turning on your generator is almost assuredly against local ordinance, national electrical code, and safe practice. You need a transfer switch, manual or automatic, which 100% eliminates any possibility whatsoever of sending power back up into the grid during an outage.
