250.122 Equipment Grounding Conductor, Sizing – https://www.MikeHolt.com/bonding. The equipment grounding conductor sizes for 15A -30A circuits are easy to remember since they are required to be full sized and are part of cable assemblies. Larger circuits, however, typically require the use of Table 250.122 and that can be a little confusing. Listen to this podcast to better understand how these conductors are sized.