For a 3-phase, 3-wire, corner-grounded system with 500 kcmil copper phase conductors, what is the minimum grounded conductor size?

In a 3-phase, 3-wire, corner-grounded system, the minimum size of the grounded conductor (neutral) is often determined by the size of the phase conductors and the requirements outlined in electrical codes, such as the National Electrical Code (NEC).

For a system with 500 kcmil copper phase conductors, the NEC specifies that the minimum size for the grounded conductor must be derived from the size of the phase conductors. In this case, when 500 kcmil copper is used for the phase conductors, the grounded conductor must also be sized appropriately to handle potential fault currents and provide effective grounding.

The NEC typically allows the grounded conductor to be of the same size as the largest phase conductor when the system is grounded and takes into account factors such as the number of conductors and the type of grounding. Therefore, using a grounded conductor size of 500 kcmil copper matches the size of the phase conductors and ensures compliance with safety and performance standards in the system.

Selecting this size also ensures that the conductor can safely handle the current loads expected in the system while maintaining system integrity and reducing potential for overheating or failure under fault conditions.