In a 3-phase wye system, how many wires are typically used?

In a 3-phase wye system, four wires are typically used. This configuration includes three conductors for the three phases (labeled as phase A, phase B, and phase C) and one neutral wire. The neutral wire serves as a return path for unbalanced loads and helps to stabilize the system voltage.

The three-phase wye connection is advantageous because it provides a lower voltage level between any phase and the neutral compared to the line-to-line voltage. The presence of the neutral wire in a four-wire system allows for both three-phase loads and single-phase loads to be connected, accommodating various electrical demands in a distribution network.

The other options fall short because a three-wire system (the first choice) would connect only the three phases without a neutral, making it less versatile for applications needing a neutral. Similarly, two wires do not provide sufficient phases or balance for a three-phase system, and five wires exceed what is necessary for standard configurations in a wye setup.