What is the ideal configuration of conductors in a service entrance with only two conductors?

The ideal configuration of conductors in a service entrance with only two conductors is single-phase. In a single-phase system, two conductors are used: one for the current to flow to the load and the other to return the current. This configuration is common for residential and light commercial applications, as it provides a straightforward and efficient means of delivering electrical power for typical household needs.

In contrast, dual-phase configurations are not as commonly referenced and might create confusion, as they typically imply a system derived from a split-phase supply, which actually consists of three wires including a neutral. Three-phase systems require three conductors and are utilized mainly in industrial settings for their ability to provide a more continuous power flow and higher loads. Quasi-phase is not a standard term in electrical design and does not describe an acceptable or recognized configuration.

Thus, single-phase is the clear choice for a service entrance with just two conductors, providing a reliable means of electrical supply for many applications.