Which service configuration is commonly required for commercial and light industrial customers?

• A. Two-phase
• B. Four-phase
• C. Three-phase
• D. Single-phase

Answer: (C)

Three-phase service is commonly required for commercial and light industrial loads because it delivers power more efficiently to motors, pumps, HVAC, and other heavy equipment. With three phases, the power delivered to a load stays more constant as each phase reaches its peak at different times, which smooths torque in motors and reduces vibration and wear. This also allows for smaller conductors and better voltage balance for the same total power, making it more economical for larger electrical demands.

Single-phase works well for small loads like lighting and simple outlets, but it becomes impractical and costly for larger commercial or light industrial systems. Two-phase isn’t a standard modern distribution configuration, and four-phase isn’t used in typical service setups. So the configuration that best fits the needs of these customers is three-phase.