250.66A compared to 250.66

[xformer]

SO, the way I understand the code, a #6 GEC is the largest GEC needed when setting a seperately derived system GEC?

 

[david luchini]

SO, the way I understand the code, a #6 GEC is the largest GEC needed when setting a seperately derived system GEC?

I don't think that is correct. The separately derived system grounding electrode should be the nearest of either water pipe electrode or structural metal grounding electrode.

260.66(A) would proscribe a "not larger than" size for pipe electrodes, but not structural steel electrodes.