when derating sevice conductors 4/0 for 3/0 copper for a 200 amp service do you use #2 for the grounding electrode conductor or #4.

[This message has been edited by lite bulb (edited 02-12-2006).]

There is no relief in 250.66 for derated service conductors. If it is 4/0 copper you need the #2

[This message has been edited by gfretwell (edited 02-12-2006).]