What is a primary feature of a delta construction configuration?

The primary feature of a delta construction configuration is that it does not incorporate a common neutral wire. In a delta configuration, the three phases are connected in a closed loop, resembling the shape of a triangle or delta, which allows for the use of three conductors without a neutral wire. This design helps in transferring power efficiently in three-phase systems, commonly used in industrial and commercial applications.

In contrast to this option, a single-phase system relies on one phase and often requires a neutral wire for completing the circuit. Residential wiring typically favors configurations that support single-phase systems and often use a neutral, making this incorrect in the context of delta configurations. The mention of residential wiring in one of the choices does not align with the typical use cases for delta configurations, which are better suited for high power and industrial applications. The requirement for a fixed voltage difference is more relevant to other configurations and not a defining characteristic of the delta arrangement itself.