"no Service Entrance conductors on the line side of the meter. There is an underground lateral coming from the utility company"
"underground lateral from the utility company" = "Service Entrance conductors"
And the GEC needs to be sized for them...
Anyway... I think its clear the code wants one GEC per lateral. Although Soares opinion might differ.... (What if one service is removed, and you have a just a #6 covering the grounding for 350MCM SE conductors?)
(D) Grounding Electrode Conductor Taps. Where a service consists of more than a single enclosure as permitted in 230.40, Exception No. 2, it shall be permitted to connect taps to the grounding electrode conductor.(singular) Each such tap conductor shall extend to the inside of each such enclosure. The grounding electrode conductor[i](singular) shall be sized in accordance with 250.66, but the tap conductors shall be permitted to be sized in accordance with the grounding electrode conductors[i](plural) specified in 250.66 for the largest conductor serving the respective enclosures. The tap conductors shall be connected to the grounding electrode conductor.[i](singular) in such a manner that the grounding electrode conductor.[i](singular) remains without a splice.
Commentary from 230.40 exception 2... "Note that in such cases the lateral conductors are considered [i]one service lateral."
Also, how can anyone do a complete job without knowing what the meter is fed with, (Not opening the meter) otherwise you would never know what size the GEC should be.
IMO the GEC crimps or welds should be right below the equipment. Or run a single conductor in and out of both panels. The allowing of taps seems to be making it easier for you... "the tap method eliminates the difficulties found in looping grounding electrode conductors from one enclosure to another." (From the commentary following 250.64(D) )
