General Order 64-A
Definitions Of Terms Used In This Order
21.8 Permanently Grounded means
connected to earth in such a manner that no current which can flow in the
ground wire will cause a harmful voltage to exist between the grounded
conductors and facilities and adjacent exposed conducting surfaces which are in
good contact with the earth, or with adjacent surfaces of earth itself, under
the most severe conditions which are liable to arise in practice.
If a resistance of less than 25 ohms is not obtained, the equivalent of two ½ inch corrosion resisting rods, not less than 8 feet in length and continuous throughout, driven to a minimum depth of 8 feet at not less than 6 foot centers will considered a permanent ground for the purpose of these rules.
Note This Rule was modified by Supplement 1. To see the changes made by supplement 1 click here. This page contains the wording of the rule prior to Supplement 1.