For a corner-grounded, separately derived system with 500 kcmil conductors, what is the minimum size requirement for the grounded conductor?

In a corner-grounded, separately derived system, the grounded conductor must be appropriately sized to ensure safety and compliance with electrical standards. For a system using 500 kcmil conductors, the grounded conductor must carry the same current as the ungrounded conductors under fault conditions.

According to the National Electrical Code (NEC), when dealing with separately derived systems, the minimum size of the grounded conductor is required to be the same as the ungrounded conductors for systems that are corner-grounded. This means that if the ungrounded conductors are 500 kcmil, the grounded conductor must also be 500 kcmil.

This sizing ensures that in the event of a fault, the grounded conductor can safely handle the return current without overheating and creating a hazardous situation. Therefore, choosing 500 kcmil copper as the size for the grounded conductor aligns with safety requirements and ensures proper functioning of the electrical system under fault conditions.