On Buildings with only One Service Section (all under One kWh Meter), I bring a GEC from the Service Equipment to the Transformer(s), with the Primary Feeder Circuit.
Ground Rod is typically driven at the Transformer, and Bonded to the SDS Grounding System via #6 Cu.
GEC is sized per 250.66, and is separate from the Branch Circuit's EGC.
GEC for the SDS is terminated at the Service Equipment, where the Grounded Conductor is bonded to the Grounding Electrode System. This effectively bonds all the Electrodes + Water & Bldg. Steel to the Service Equipment and the SDS(s).
Where several Electrodes are used, along with the need to terminate many GECs, EGCs, and other Jumpers, a "Grounding Grid Plate" is used.
On large Projects with remote Distribution Sections, a "Grounding Grid Plate" is setup at each Distribution Section.
When there are several Metered Service Sections across one large Building (like 100,000 Sq, Ft. and larger), the Grounding Electrode Systems and Schemes become more interesting!
Typically it's several "copies" of the methods explained above - one or more of the schemes, as fits the scenario.
Scott
