I have an existing school that was built in late 70's or early 80's. For a summer renovation part of the scope was to replace a 400 amp and 600 amp 480 volt fusible panels with new panels and breakers. When the existing panels were opened it was discovered that the 400 amp was fed with 4 #500 KCM and 1 #6 ground and the 600 amp was fed with parallel sets of 4 #350 KCM and 1 #10 ground. The school district does not have money to re-pull the existing feeders with the appropriate sized equipment grounds (approximately 300 feet each). In looking at section 300.3, B (2) and 250.130 (C) it appears that running an equipment grounding conductor outside the raceway is not acceptable except for receptacles and branch circuits. I was just curious if anyone knew of anything else in the code that would allow the contractor to ground these panels so they would comply with code without having to re-pull new feeders. I forgot to mention that the raceway is below a suspended slab and is PVC.
