General Order 95
Definitions of Terms as Used in The Rules of This Order
21.4     Grounded means connected to earth by a ground connection
or by an unintentional conducting path.
A.     Effectively Grounded means grounded through
a ground connection of sufficiently low impedance (inherently and/or intentionally
obtained) that fault grounds which may occur cannot build up voltages dangerous
to connected equipment.
(1)     If an impedance of less than 25 ohms
is not obtained, the equivalent of a ground conductor not less than No. 6
AWG copper connected to two corrosion resisting rods, not less than 1/2 inch
in diameter and 8 feet in length and continuous throughout, driven to a minimum
depth of 8 feet in the earth at not less than 6 foot centers, will be considered
an effective ground for the purpose of these rules.
(2)     Where a common neutral system is installed,
the grounding provisions for such systems, as covered in
, shall apply.
B.     Permanently Grounded refers to time, and means
grounded while the equipment concerned is in place under the conditions specified
in the rules.
C.     Securely Grounded means connected to earth through a
metal surface in good contact with the earth (soil, rock, etc.) such as the
contact of anchor rods or metal poles set directly in the ground. Metal poles
set in concrete are considered as grounded but will not be considered as securely