A service entrance with four connected conductors is classified as what type of supply?

The classification of a service entrance with four connected conductors as a three-phase supply is based on the standard configuration and operation of three-phase electrical systems. In a typical three-phase supply, three conductors carry alternating currents that are phase-shifted by 120 degrees, allowing for a more efficient transmission of electricity compared to single-phase systems.

The fourth conductor usually serves as a neutral or ground, allowing for the balancing of the load across the three phases. This configuration enables the supply to deliver more power for industrial and commercial applications, where high efficiency and reliable service are essential. The three-phase arrangement provides smoother and more stable power delivery, which is crucial for operating large motors and equipment.

Given this context, the designation of a service entrance with four conductors as a three-phase supply reflects the common practice and understanding in electrical systems design and installation.