Which service is typically required for commercial and light industrial customers?

• A. Three-phase service
• B. Split-phase service
• C. Single-phase service
• D. Four-phase service

Answer: (A)

Three-phase power is used for commercial and light industrial loads because it efficiently handles motors and other heavy equipment that are common in these settings. With three separate conductors, each phase shares the load, providing nearly constant power and smoother torque to motors. This means motors start and run more efficiently, with lower current requirements for the same horsepower, allowing smaller wiring and transformers and reducing voltage drop and losses. In contrast, single-phase (split-phase) service is usually enough for small loads like lighting and office equipment but becomes impractical for multiple large motors due to higher current and less efficient starting. Four-phase service isn’t a standard utility arrangement. So, three-phase service is the typical requirement for commercial and light industrial customers.