In a three-phase system, which connection has a neutral conductor?

In a three-phase system, which connection has a neutral conductor?

• A. Delta
• B. Wye
• C. Isolated
• D. Open-delta

Answer: (B)

In a three-phase system, a neutral conductor is provided when the windings are connected in a Wye (star) arrangement. The three windings meet at a common point, forming the neutral point, from which a neutral conductor can run to loads. This setup enables line-to-neutral voltages (for example, 120 V or 277 V depending on the system) in addition to the line-to-line voltages. Delta configuration forms a closed loop with no common neutral point, so there isn’t a neutral conductor available. Isolated or open-delta arrangements similarly do not provide a normal neutral path.

In a three-phase system, a neutral conductor is provided when the windings are connected in a Wye (star) arrangement. The three windings meet at a common point, forming the neutral point, from which a neutral conductor can run to loads. This setup enables line-to-neutral voltages (for example, 120 V or 277 V depending on the system) in addition to the line-to-line voltages.

Delta configuration forms a closed loop with no common neutral point, so there isn’t a neutral conductor available. Isolated or open-delta arrangements similarly do not provide a normal neutral path.