What is the standard voltage used in residential electrical systems in the United States?

Residential electrical systems in the United States commonly use a standard voltage of 120/240 volts. This configuration allows for two different voltages supplied to homes: 120 volts is typically used for standard household appliances and lighting, while 240 volts is utilized for more demanding appliances such as dryers and ovens. The typical household service is split-phase, which means that the electrical service has both a high and a low voltage available, providing versatility to accommodate various electrical needs in the home.

The use of both 120 and 240 volts is significant as it aligns with the appliance requirements present in most American households, facilitating the efficient operation of a wide range of electrical devices.