If you were to connect two panels to the secondary of the transformer (within 10?-0?) how would you size the grounding electrode conductor from the transformer to the building steel? if you are required to size it according to 250.66 the size of the largest ungrounded conductor is this correct because you essentially have two smaller conductors, or would you base it like you installed a single ocpd and use that conductor size? (ex. 75kva xfmr with two secondary feeds #1 to two panels with 125A mcb in each you run a #6ground to each panel board but what about from the xfmr to steel a #6 also or a #2 based on secondary fla conductors?)