In what type of service is a 120/240-volt, single-phase, 3-wire supply typically used?

A 120/240-volt, single-phase, 3-wire supply is typically used in residential settings, most commonly found in single-family dwellings. This type of electrical service provides sufficient capacity to handle general household needs, including lighting, outlets, and small appliances. The 120-volt supply is suitable for standard household devices, while the 240-volt supply is ideal for larger appliances like water heaters or dryers.

Using it in an apartment complex, while possible, does not accurately represent the primary application since individual units may instead use separate transformer supplies tailored for multi-unit setups or service configurations that differ, such as three-phase systems for larger buildings to accommodate heavier loads.

In comparison to commercial buildings and industrial facilities, which typically require higher voltage levels and three-phase systems for efficient power distribution, the single-phase 3-wire configuration is more aligned with the loads and requirements of single-family residences.