Re: 6 ohms
Breakers are designed to carry 125% of their rated ampacity for 1500 seconds (30 minutes). In order to trip reliably and quickly in a fault situation a breaker should see 5 times its rated current. In order for a grounding electrode to provide an effective fault return path it would need to have a resistance much lower than 6-ohms. It would still be inviolation of that section that says the earth shall not be used as the fault return path.
Also remember that usually we are measuring resistance from the rod to the earth immediately surrounding the rod (using a 3-point, or fall-of-potential method) we really don't know what the total resistanc would be for current trying to return to "source" in order to trip a breaker.
[ December 15, 2005, 08:14 AM: Message edited by: haskindm ]