Seriously, 20A? How do you even run an air conditioner on that, much less an entire house? 200A (at 240V split phase) is standard here in the Midwestern US. It's easy and cheap to get more if you want a better connection, such as for an EV or a home shop with welders and large motors.
> Seriously, 20A? How do you even run an air conditioner on that, much less an entire house?
The poster mentioned Spain, which uses 230V (unlike the USA, which uses 120V), so 20A should be around 4600W if I did the calculation correctly. With a quick search I found a window AC with 18000 BTU using only 1700W, so even with 15A it would be possible to run one AC with plenty to spare.
The USA uses 120V for outlets and lighting, but most buildings have what we call "split phase" where 240V is available between two opposing sine waves. A neutral down the middle gives you 120 from either of these phases. Large appliances run on 240V dedicated circuits, the rest are 120.
And 4600 KW is only a couple tons. You'll need more than that for a 5-ton central HVAC to cool an average house in a hot or humid area.
No, as the other poster pointed out, the US is 240 volts not 120 for this discussion. 120 volts is what you get to your general use outlets, but when we say a house in the US has 200 amps of mains service, we mean 200 amps at 240 volts, or 400 amps at 120 volts. The split to 120 volt happens in your mains panel after the main breaker.
