What is the minimum size required for a grounding electrode conductor if the ungrounded system conductors of a 4,160-volt system are sized at 4/0 AWG?

To determine the minimum size required for a grounding electrode conductor in the context of a 4,160-volt system, it's essential to refer to the National Electrical Code (NEC) guidelines, which specify the sizing requirements based on the ungrounded system conductors. For systems that operate at voltages like 4,160 volts and with ungrounded conductors sized at 4/0 AWG, the NEC requires that the grounding electrode conductor must be appropriately sized to ensure adequate protection and safety.

According to NEC Table 250.66, for system conductors of 4/0 AWG, the minimum size for the grounding electrode conductor is typically 2 AWG. This ensures that the grounding system can effectively handle potential fault currents and provide a safe path to ground in case of unintended electrical faults.

By selecting a grounding electrode conductor of this size, the system is compliant with NEC requirements, promoting safety through proper grounding practices. Thus, the choice of 2 AWG aligns with these critical safety standards.