Quote Originally Posted by kwired View Post
Because EGC and GEC have different functions. A rod or pipe electrode never needs more than 6 AWG copper run to it because the electrode will not dissipate any more energy into the earth than a 6AWG can deliver to it, they just don't have low enough resistance to earth to do that. Same with the CEE, except they do have lower resistance than a rod or pipe but never low enough that more than a 4 AWG is necessary. I don't know who determined this but that is basically why you never need larger than those sizes as the sole connection to said electrodes.
The energy that a 6 or 4 can dissipate is limited by its impedance - particularly at lightning frequencies. At high frequencies there is little difference between a 6 and 3/0. Plus the ground rod or ufer is limited...probably whats somewhat more important is stabilizing the voltage.

However in the long run, our GEs don't really do that much in a lightning event. If you want lightning protection then a full blown lightning system is needed.

Drive two and go home, or use the Ufer. Our focus should be on bonding.