Original
General Order
95
Section
III
Requirements for All Lines
32.4 Circuits of Different Classification on the Same Crossarm
A. Supply Circuits
(1) 750-7500 Volts and More than 20,000 Volts: Supply circuits of 750-7500 volts shall not be carried on the same crossarm with circuits of more than 20,000 volts unless the higher voltage circuit is not energized when men are working at this level. Where construction is used, circuits of different classifications shall be carried on opposite ends of the crossarm with a horizontal separation of not less than pin spacings required for the highest voltage concerned, but not less than 36 inches between the nearest conductors of different classification.
(2) 0-750 Volts and More Than 7500 Volts: Supply circuits of 0-750 volts shall not be carried on the same crossarm with circuits of more than 7500 volts, except that, on transformer structures, bus conductors of 0-750 volts and bus conductors of 7500-20,000 volts may be supported on opposite ends of the same bus-supporting timbers provided the horizontal separation between conductors of different classifications supported on the same arm is not less than 36 inches, the bus conductors of 7500-20,000 volts are not extended longitudinally as line conductors, service drops are not supported on arms which support conductors of 7500-20,000 volts, and conductors on related buck arms are not less than 4 feet vertically from such bus timbers.
(3) 0-750 Volts and 750-7500 Volts: Supply circuits of 0-750 volts and 750-7500 volts which are owned and operated by the same utility may be carried on opposite ends of the same crossarm with the nearest conductors of the two classifications separated a horizontal distance of not less than 36 inches. For requirements applicable to buck arm construction, climbing space, and service drops on combination arms, see Rules 54.4-C2b, 54.7 and 54.8-E respectively.
(4) More than 750 Volts, Different Ownership: Supply circuits of more than 750 volts and of different ownership may be carried on opposite ends of the same crossarm with the nearest conductors of different ownerships separated a horizontal distance of not less than 36 inches, provided proper ownership designation is maintained.
(5) 0-750 Volts, Different Ownerships: Supply circuits of 0-750 volts and of different ownership may be carried on opposite ends of the same crossarm with the nearest conductors of different ownerships separated a horizontal distance of not less than 30 inches.
(6) Common Neutral Conductor: See Rule 59.3-E for the location of the common neutral conductor in common neutral systems.
B. Supply Circuits of 0-750 Volts and Communication Circuits
Supply circuits of 0-300 volts and Class C communication circuits of different ownership may be supported on the same crossarm, 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 horizontal distance of not less than 36 inches. Where the two classes of circuits are of the same ownership, the horizontal distance may be reduced to not less than 30 inches and the supply circuit voltage may be 0-750 volts. Services direct from such a crossarm are not permitted to cross conductors of the other classification supported on the same crossarm.
C. Supply Circuits and Private Communication Circuits(see Rules 20.5-B and 89)
(1) 7500-20,000 Volts, Same Ownership: Supply circuits of 7500-20,000 volts and private communication circuits owned (or leased) and operated and maintained by the same organization may be supported on the same crossarms as provided in Rule 89.2-A1.
(2) 750-7500 Volts, Same Ownership: Supply circuits of 750-7500 volts and private communication circuits owned (or leased) and operated and maintained by the same organization may be supported on the same crossarms as provided in Rule 89.2-A2.
(3) 0-750 Volts: Supply circuits of 0-750 volts and private communication circuits may be supported on the same crossarms as provided in Rule 89.2-A3, or Rule 89.2-A4.