Question

A single-phase 230 volt feeder supplies a 100 amp subpanel that MUST be grounded. What's the smallest size copper equipment grounding wire REQUIRED for the subpanel?

Answer 1

The smallest size copper equipment grounding wire required for the subpanel is 8 AWG.

Step-by-step explanation:

In this scenario, we need to determine the smallest size copper equipment grounding wire required for a 100 amp subpanel that is supplied by a single-phase 230 volt feeder. According to the National Electrical Code (NEC), the minimum size grounding conductor for a 100 amp circuit is typically determined based on the size of the phase conductors. For a 100 amp circuit with 2-4 AWG phase conductors, the NEC recommends a minimum 8 AWG copper equipment grounding conductor.