When talking about the voltage of US residential service, and the devices that use it, 240 and 220, and 120 and 110 are functionally the same. The house theoret

When talking about the voltage of US residential service, and the devices that use it, 240 and 220, and 120 and 110 are functionally the same. The house theoretically has 240v and 120v power, but voltage may sag throughout the home's wiring, and some outlets will a real voltage reading lower than 240/120.