As was mentioned briefly in an earlier post, if you use a covered or insulated conductor for the GEC, as is allowed by the NEC, and you use a conductor insulated or covered that is black, aren't you then prohibited by art. 310.12(c)from using a black insulated conductor as an UNGROUNDED conductor anywhere else in the same electrical system? Art. 310.12(C)" Conductors that are intended for use as ungrounded conductors, whether used as a single conductor or in multiconductor cables, shall be finished to be clearly distinguishable from grounded and grounding conductors." The same being true if you used any other color conductor other than green since art. 200.6 requires all GROUNDED conductors to be white or natural gray and specifically NOT green. So by deductive reasoning here's my interpretation: The grounding electrode conductor can be bare or covered or insulated. If it is covered or insulated it cannot be white, natural gray or the same color as any UNGROUNDED conductor within the same electrical system. Since a green ungrounded conductor is a clear violation we know there won't be any green UNGROUNDED conductors in an electrical system(at least not intentional ones). As I see it the 2002 NEC compliant installation is either bare or, if insulated or covered, green or re-marked with green. Doesn't the NEC make it clear that GROUNDED conductors must be identified with white or natural gray. GROUNDING conductors must be bare, green or green with yellow stripes. UNGROUNDED conductors must be covered or insulated and can be identified with any color NOT assigned to the GROUNDED or GROUNDING conductors as set forth in arts. 250.119 and 200.6.
