250.66(A) states that if is the sole connection it is not required to be larger than #6 CU or #4 AL. It is a 400amp four meter service. What size is the grounding electrode conductor required to be if there is nothing but the conductor and two ground rods attached to the meter? What would be required for a 400AMP single meter service with the same grounding situation? Will #6 CU be correct?