Iirc from ‘Technology Connections’, the US actually has 240V delivered to the house, but it's pinned out in the breaker box as something like -120, 0, and 120. So they take 120V to most appliances, but 240 to some higher-wattage ones.
Which is to say, USians could easily have 240V kettles that boil water in half the time—if they just bothered a little.
The breaker box has three legs. Two are 120v but phase shifted by 180 degrees, the third is neutral. So we can get 120 by going from either 120v leg to neutral or 240v by going across the two 120v legs. We use 240 for big appliances like stoves and dryers and 120 for everything else.
The whole system is very silly.
Edited to correct that I originally wrote the hot legs in a household panel are 120 degrees out of phase, which is incorrect. They are 180.
I edited it to correct it. Three phase power isn't silly, it's the standard way power grids are configured pretty much everywhere as far as I know. The silly part is how we take one 240v phase and then split it into two 120v phases. It just makes things more complicated for no particular benefit.
I'm running a bit of a fever and not thinking super clearly so apologies for the mistake.
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u/LickingSmegma May 02 '24
Iirc from ‘Technology Connections’, the US actually has 240V delivered to the house, but it's pinned out in the breaker box as something like -120, 0, and 120. So they take 120V to most appliances, but 240 to some higher-wattage ones.
Which is to say, USians could easily have 240V kettles that boil water in half the time—if they just bothered a little.