Alan- I would argue that the conductor used for corner grounding is not a "grounded conductor" in the sense that it is used for a feeder or branch circuit but instead it is used to connect the system to a grounding electrode so it would not have to be white or grey. The few corner grounded systems I've seen are connected to the grounding electrode with a conductor identified with green tape. If I'm wrong, I need to be corrected. When you install a GEC to an electrode on a mid-point grounded system you are not required to have the GEC white.
I might add that I would prefer that they use either uninsulated or green and stay away from white so there is no confusing it with a "neutral" "grounded" conductor. Because you are correct grounded conductors conductors are required to be white or grey per Article 200.
Last edited by George Little; 07/18/10 04:38 PM. Reason: Added thought.
