General Order 64-A
32.5 Circuits of Different Classification on One Cross Arm.
A. Supply Circuits.
(1) More Than 17,000 Volts and Less Than 7500 Volts: Supply circuits in excess of 17,000 volts shall not be carried on the same crossarm with circuits of less than 7500 volts unless the higher voltage circuit is not energized when working at this level. (See App. G, Fig 11.)
(2) 0-750 Volts and 750-7500 Volts: Supply Circuits of 0-750 and 750-7500 volts which are owned and operated by the same utility may be carried on the opposite ends of the same crossarm. Where buck arms are used in connection with such cross arms at 2 foot spacing, this horizontal distance between conductors of the two classifications shall be increased of 42 inches. (See App. G, Fig. 12.)
(3) More Than 750 Volts, Different Ownership: More than one supply circuit of different ownerships in excess of 750 volt may be carried on the same line cross arm with a minimum horizontal separation of 36 inches, provided proper ownership designation is maintained. (See App. G, Fig. 13.)
(4) More Than and Less 750 Volts: Where supply conductors carrying voltages less than 750 volts are installed on the same cross arm with conductors carrying voltages in excess of 750 volts, the nearest conductors of the two classification shall be separated a minimum horizontal distance of 36 inches. (See App. G, Fig. 12.)
B. Supply Circuits of 0-750 Volts and Communication Circuits.
Supply circuits of 0-750 volt and communication circuits may be supported on the same cross arm, provided the two classifications of circuits are installed on opposite ends of the arm and the nearest conductors of the two classifications are separated a minimum horizontal distance of 36 inches. Where of the same ownership, the minimum horizontal distance may be reduced to 30 inches. Services direct from this cross arm are not permitted to cross different classifications on the same cross arm. (See App. G, Figs. 14 and 15.)
C. Supply Circuits and Communication Circuits Not For Public Use.
(1) Less Than 17,000 Volts, Same Ownership: Communication circuits not for public use and supply circuits of less than 17,000 volts which are owned and operated by the same utility may be supported on the same crossarm where necessary. (See App. G, Fig. 16.)
(2) 0-750 Volts, Same Crews of Workmen: Supply circuits of 0-750 Volts and communication circuits not for public use which are operated and maintained by the same crews of workmen may be supported on the same end of the cross arm provided the horizontal clearances between the two classes of circuits shall not be less than the pin spacing required of the supply circuits shall preferably be carried on the outer pin positions. (See App. G, Fig. 17.)