Change List for this Rule

 

General Order 95

 

Section III

 

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 circuit 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 crossings or extensions to existing lines are to be installed.

 

A.    Supply Circuits of 750 - 20,000 Volts

Supply circuits of 750 - 20,000 volts should not be above supply circuits in excess of 20,000 volts.

 

B.    Supply Circuits of 0 - 750 Volts

Supply circuits of 0 - 750 volts should not be above supply circuits in excess of 7,500 volts.

 

C.    Supply Circuits of 0 - 750 Volts and Class T Circuits

Supply circuits 0 - 750 volts and 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.

 

D.    Communication Circuits

Communication circuits should not be above supply circuits in excess of 7,500 volts. Insulated single conductors, paired wire or duplex communication line conductors above supply circuits (including Class T circuits) of 750 - 7,500 volts shall be supported on messengers or constructed in accordance with
Rule 32.2G .

 

E.    Supply Service Drops of 0 - 750 Volts

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.

 

F.    Communication Service Drops

Communication service drops should not cross in a span above supply circuits (excepting Class T circuits) of 750 - 7,500 volts and shall not cross in a span above supply circuits in excess of 7,500 volts. Where it is necessary that communication service drops cross in a span above supply circuits of 750 - 7,500 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 means of attachment.

 

G.    Exceptional Cases

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.