What is the minimum size of a copper equipment grounding conductor required for an 800-ampere feeder?

The minimum size of a copper equipment grounding conductor for an 800-ampere feeder is determined based on the requirements outlined in the National Electrical Code (NEC). According to NEC Table 250.122, the size of the equipment grounding conductor is based on the rating of the overcurrent protection device.

For an 800-ampere feeder, the corresponding minimum size for a copper conductor is 1/0 AWG. This is because as the size of the feeder increases, so does the requirement for a larger equipment grounding conductor to ensure adequate safety and protection against electrical fault conditions. This size ensures that the grounding system can effectively handle ground fault currents.

The other sizes listed do not meet the minimum requirements set forth for an 800-ampere feeder, making 1/0 AWG copper the appropriate choice for compliance and safety reasons.