Which factors influence the selection of conductor size?

The selection of conductor size is primarily influenced by the amperage load and the length of the run. Amperage load refers to the amount of current that will flow through the conductor; if the load is high, a larger conductor is needed to safely carry that current without overheating. Additionally, the length of the run is important because the longer the distance the electricity has to travel, the more resistance is encountered, leading to voltage drop. This voltage drop can affect the performance of the electrical system; thus, larger conductors are often required for longer runs to minimize this effect.

While other factors, such as conduit length and type of circuit or voltage and frequency, may also play a role in the overall installation and performance of the electrical system, they do not directly impact the determination of conductor size in the same way that amperage load and run length do. Therefore, focusing on amperage load and run length specifically addresses the core considerations for selecting the appropriate conductor size.