How many legs are present in a 3 phase incoming service?

In a typical 3-phase incoming service, there are three phases, often referred to as "legs." Each phase carries alternating current (AC) that is offset by 120 degrees from the other phases, providing a consistent and balanced power supply. This setup is essential for powering large motors and heavy industrial equipment, as it reduces the amount of current needed for the same amount of power compared to single-phase systems.

In a common configuration, a 3-phase service will also include a neutral leg, making a total of four conductors. This neutral is used for unbalanced loads and provides a return path for current, ensuring that the system can operate safely and effectively.

Therefore, the correct number of legs in a standard 3-phase service setup, when accounting for the neutral, is indeed four. This is crucial for understanding how electrical systems are designed and how they function, especially in commercial and industrial applications.