> Going to more than 20amp requires a multiphase circuit There is no multi-phase power available in the vast majority of US houses. A typical residence has a 1

> Going to more than 20amp requires a multiphase circuit There is no multi-phase power available in the vast majority of US houses. A typical residence has a 120/240 split-phase service, which is single-phase only. A service drop is two hot conductors from two of the three transformer phases and a center-tapped (between the two hot legs) neutral conductor. Either hot leg is 120v to ground and line to line is 240V. > https://en.m.wikipedia.org/wiki/Split-phase_electric_power https://en.m.wikipedia.org/wiki/Split-phase_electric_power Single-phase breakers are also available in sizes larger than 20A, usually all the way up to 125A.