system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why is it that when you increase voltage from 120 to 220, the total amperage ends up being the same as if you did not change voltage at all?

I've been trying to wrap my head around this for a little while. If you have 2000 watts at 120, the amperage is 16.7. If you have it at 220, it's 9.09. But that 9.09 amps ends up on 2 different legs, so you end up with a total of 18.18 amps. Isn't voltage supposed to decrease amperage? Whats going on here?
gpt
You're confusing stepping voltage up or down via a transformer (and since power equals voltage times amperage, as one goes down the other must go up) with the two phases of voltage that is supplied to a typical US house.  You aren't stepping anything up and down when you place a large appliance across both phases in order to provide it with a total of 240VAC. Most electrical devices in a house, of course, only need 120VAC and are connected across one phase (or the other) and the neutral wire.  Two phases of 120VAC, 180 degrees out of phase from each other, combine as a single phase of 240VAC when you connect a large appliance across both phases. Internal components inside that appliance that only need 120VAC (such as an electronic controller) will only be connected across one phase and the neutral wire.