What is the minimum-size copper equipment grounding conductor required for an 800-ampere, 2,300-volt feeder installed in PVC conduit?

To determine the minimum size of the copper equipment grounding conductor required for an 800-ampere feeder, it's essential to refer to the National Electrical Code (NEC) guidelines, particularly the tables that specify grounding conductor size based on the feed's ampacity.

For an 800-amp service, the NEC provides a table that outlines the required sizes for equipment grounding conductors. According to the NEC, for feeders, the minimum size copper grounding conductor is determined by the rating of the overcurrent protective device (in this case, the feeder, rated at 800 amps).

When consulting the appropriate NEC table, one finds that for an 800-amp feeder, the minimum size copper equipment grounding conductor is 1/0 AWG. This value is established considering the need to ensure adequate conductivity and safety for grounding under normal operating conditions and potential fault scenarios.

Thus, the correct answer is 1/0 AWG, as it aligns with NEC requirements for protecting both the feeder and the equipment it serves under fault conditions. The other options indicate sizes larger than this minimum requirement, which may not be necessary unless specific conditions dictate otherwise.