If a feeder supplying a separate building is sized at 2,500 amperes, what is the maximum size for the copper grounding electrode conductor required?

The maximum size for the copper grounding electrode conductor (GEC) required when a feeder supplying a separate building is sized at 2,500 amperes is 6 AWG. This is determined by the National Electrical Code (NEC), which establishes guidelines for grounding conductors based on the size of the service or feeder supplying the building.

According to NEC Table 250.66, the size of the grounding electrode conductor must be appropriate for the largest ungrounded conductor in the service. For a feeder that is rated at 2,500 amperes, the code specifies that the GEC must be a minimum of 6 AWG copper to ensure proper grounding and safety.

Using a conductor that is too small could result in inadequate grounding, which can lead to various electrical safety hazards. A larger GEC size does not change the effectiveness of the grounding but must meet the minimum requirements to adequately protect the system.