I'll try to make this simple. 80A OPD required for protection my PV system. 400' run from inverter main lug panel to disconnect at house. Have to oversize to 350 mcm AL with 2/0 AL EGC to maintain acceptable voltage drop, but seems impractical to tie this size wire in at either end (out of 100A meter socket at array location or out of 100A fused disconnect at house location). If I drop down to #4 CU at either end for my 80A opd rating, am I correct that I can still use a #8 CU egc (per 250.122) since I am not up-sizing for voltage drop. Seems a little counter-intuitive to be able to go from a #8 to a #2/0 and back to a #8.