According to NEC guidelines, which size of conductors must be stranded when installed in raceways?

In the National Electrical Code (NEC), the regulation regarding the installation of conductors in raceways is designed to ensure flexibility and proper installation practices. Specifically, for smaller conductors, stranded wire is preferred because it offers greater flexibility compared to solid wire, which can be more challenging to work with in tight spaces.

The guidelines specify that conductors of 8 AWG and smaller must be stranded when installed in raceways. This requirement helps prevent potential damage to the conductors as they are pulled through the raceways, as well as minimizing issues related to bending and movement. Therefore, the correct option in the context of this question is that 8 AWG conductors must be stranded when installed in raceways, ensuring they maintain their integrity through installation and operation.

Understanding this NEC guideline is crucial for compliance and safety during electrical installations.