system
Given the following post, respond as if you're commenting on Reddit:
human
How do Americans get 115V?

Well obviously from a plug socket, but I digress.

In Europe, our power is generated in 3 phase (Red, Blue, Yellow, all 120 degrees apart), and when it's transformed down to its consumer power level, the voltage across any two phases is 400V. When there is a star load, you can take power from a single phase relative to the star point, and that comes out as 230V.

How does America get 115V? Is it transformed down from 230V at some point? Is the 3-phase voltage different? Is there some other witchcraft going on?
gpt
most of us do get 240V to the home, as a single phase- but that phase is "split" - the transformer that supplies the house is center-tapped, that center is pinned to ground, so there's effectively a +120 and a -120.  obviously not really positive and negative since it's a/c, but they're 180° out of phase.  so some circuits get one polarity, some get the other, and if we need the full 240 (like for an air conditioner or the stove, etc) we use both.