General Order 64-A
Detailed Construction Requirements For Supply Lines
(Class H, L and T Circuits)
Bonding and Grounding.
Bond wires and ground wires may be carried on face, back or under side of cross arms, provided they are installed so as to permit the least possibility of contact and shall clear all hardware, not intended to be bonded or grounded, by not less than 1 ½ inches. Where said wires are suitably protected or installed as shown in Figure 64, Appendix G, the clearance may be reduced to ¾ inch. The conductor used for bonding shall have a conductivity of not less than No. 10 A.W.G. copper wire.
Where single circuits are involved the bond wire may be carried down the pole to a point not less than 3 feet above the next circuit level below less than 3 feet above the next circuit level below and need not be covered with a protective covering. This 3 foot clearance also applies to metal crossarm braces which are in contact with hardware or bond wires.
Where twin circuits are at the same conductor level, the following rules shall apply:
Where separate bond wires are used, they shall be separated by one-half the circumference of the pole and where run on the surface of the pole, they shall be protected by a suitable protective covering. Where a common bonding system is used, neither circuit shall be worked on while either circuit is energized; the bond wire shall not extend within 3 feet of any circuit below it unless a protective covering is used.