the minimum size copper grounding electrode conductor tap fora separetly derived A/C system with 3 sets of 300 kcmill copper secondary conductors .Thanks Bill
look at 250.30 sends you to TA 250.66, 3 sets of
300 kcmil needs a 2/0 copper electrode,
you need to add the equivalent area for parallel
conductors per phase 3 X 300 = 900
