What is the common point on a wye-connection in a polyphase system or midpoint on a single-phase system?

In both polyphase systems with a wye connection and single-phase systems, the common point is referred to as the neutral. In a wye configuration, three phases are connected to a single point, which serves as the reference point for all the phases. This neutral point allows for the return path of current in three-phase systems, providing stability and balance.

In single-phase systems, the neutral acts as the midpoint between the two live conductors. This helps in establishing a balanced voltage supply, ensuring that the voltage levels remain stable and providing a safe return path for current back to the source.

Understanding the role of the neutral is crucial for various electrical applications and ensures safe electrical practices, such as proper grounding and circuit protection. Thus, neutral is the correct designation for the common point in these systems.