General Order 95
Section III
Requirements for All Lines
33.3 Ground Connections
A. Effective Grounds
Supply equipment of the following types, when grounded to
conform to requirements of this Order or for any other reasons, shall be
effectively grounded:
• Neutral conductors of low voltage supply
circuits (0 - 750 volts, see Rule 58.2–A
);
• Neutral conductors of supply circuits exceeding 750 volts;
• Bond wires;
• Lightning arresters;
• Transformer cases grounded in accordance with
Rule 58.2–A
.
B. Independent Ground Connections
Ground connections for equipment of any one of
the types listed in Rule 33.3–A
shall not be interconnected with ground connections for equipment of any
other type listed therein, EXCEPT:
In common neutral systems the neutral conductors
of 0 - 750 volt supply circuits and of supply circuits of 750 - 22,500 volts
may be interconnected and grounded in accordance with the provisions of
Rule 59
; and
A ground connection for a set of lightning arresters may be interconnected
with:
A ground connection for the neutral
conductor of the circuit protected by the set of lightning arresters,
A ground connection for the neutral conductor of a dedicated transformer
and associated equipment cases solely for the purpose of providing power
to operate electric utility supply equipment,
The cable sheath or body of the cable pothead where the cable conductors
are connected to the circuit protected by the set of lightning arresters,
Metallic conduit enclosing conductors of the circuit protected by the set
of lightning arresters,
Transformer cases grounded in accordance with
Rule 58.2–A
where the transformers are connected to the circuit protected by the set
of lightning arresters, and
The ground connection of another set of lightning arresters, provided the
circuits protected are of the same voltage classification.
Where more than two sets of lightning
arresters on supply circuits of the same voltage classification are installed
on a pole or structure, and their ground terminals are interconnected at
the top of the ground connections, two complete and effective ground connections
will be considered sufficient for the purposes of this rule. Connection
to an effectively grounded cable sheath or conduit of a circuit protected
by the lightning arresters will be considered as one of these two effective
ground connections.
Note: Revised March 29, 1966 by Decision No. 70489, August 9, 1966 by Decision No. 71094 and October 9, 1996 by Resolution SU–40.