Requirements for All Lines
32.2 Relative Levels
Where supply and communication circuits or supply circuits of different voltage classifications are involved in crossings, conflicts or joint use, the higher voltage circuits shall in general be carried at the higher level. This arrangement is not feasible in all cases, for example where trolley circuits are involved or where poles are jointly occupied.
It is recommended that lines be arranged by mutual agreement of those concerned at standardized voltage levels throughout a given community in order to minimize difficulties when new crossing or extensions to existing lines are to be installed.
Supply Circuits of
Supply circuits of 750-20,000 volts should not be above supply circuits in excess of 20,000 volts.
Supply Circuits of 0-750 Volts
Supply circuits of 0-750 volts should not be above supply circuits in excess of 7500 volts.
Supply Circuits of 0-750 Volts and
Class T Circuits
Supply circuits of 0-750 volts all Class T circuits may cross under communication and railway circuits provided clearances not less than those given in Tables 1 and 2 are maintained.
Communication circuits should not be above supply circuits in excess of 7500 volts. Insulated single conductors , paired wire or duplex communication line conductors above supply circuits (including Class T circuits) of 750-7500 volts shall be supported on messengers or constructed in accordance with Rule 32.2-G.
Supply service drops of 0-750 volts shall not cross in a span above supply circuits (excepting Class T circuits) in excess of 750 volts, but service drops may cross above such circuits when supported on the same pole.
Communication Service Drops
Communication service drops should not cross in a span above supply circuits (excepting Class T circuits) of 750-7500 volts and shall not cross in a span above supply circuits in excess of 7500 volts. Where necessary that communication service drops cross in a span above supply circuits of 750-7500 volts, an auxiliary attachment or its approved equivalent shall be used at the service end of the service drop to insure against the drop falling across the supply circuit in the event of the failure of the usual mans of attachment.
Where it is not possible to conform to the usual arrangement whereby the higher voltage circuit shall be carried at the higher level, the positions may be reversed provided the lower voltage circuit, installed at the higher level shall be erected and maintained with the same strength requirements as the higher voltage circuits would require with the usual arrangement of levels. Where neither circuit carries in excess of 750 volts this provision does not apply.
Where supply and communication circuits carrying less than 750 volts cross trolley contact conductors carrying in excess of 750 volts, they shall conform to the strength requirements for supply lines corresponding to the voltage of the trolley contact conductors.