What defines a "feeder" in electrical systems?

A "feeder" in electrical systems is defined as a circuit that supplies power to subpanels. This is a critical function in electrical distribution as feeders are responsible for carrying electrical power from the main service panel, or another source, to secondary panels known as subpanels. This setup allows for organized distribution of electricity throughout a building, simplifying the management of electrical loads by effectively dividing the power among different areas or circuits.

In contrast to the other options, the definition emphasizes the role of feeders not just in providing power broadly, but specifically in supporting subpanels which then distribute power to various branch circuits and devices. This makes the understanding of feeders essential in designing and implementing efficient and safe electrical systems. For instance, simply providing power to devices does not highlight the system's structure or the function of power distribution within a building.

The mention of smart devices refers more to the category of the devices rather than the function of the electrical circuit, and temporary lighting does not align with the permanent infrastructure typically associated with feeders. Overall, recognizing feeders as circuits that channel power to subpanels highlights their importance in establishing a safe and effective electrical system.