What is the minimum size required for an equipment grounding conductor not part of a medium-voltage cable assembly?

The minimum size required for an equipment grounding conductor not part of a medium-voltage cable assembly is determined by the National Electrical Code (NEC) guidelines. For equipment grounding conductors, the requirement is based on the rating of the circuit conductors and the material used. Specifically, for copper conductors, the minimum size is 6 AWG, while for aluminum conductors, it is 4 AWG.

This answer aligns with the NEC, which emphasizes the importance of adequately sizing grounding conductors to ensure safe operation and prevent hazards such as electrical shock or fire. By ensuring the grounding conductor can effectively carry fault current, it contributes to the overall safety and reliability of the electrical system. Therefore, the correct choice represents the minimum standards set forth for effective grounding practices in non-medium voltage installations.