SU5 GO95 rule 54.6E

Risers from underground cables or other conductors shall be encased in grounded iron or steel shall (or other covering of equal strength) from the ground line to a level not less than 8 feet above ground line (see App. G, Fig. 61)

Risers from underground cables may be encased in plastic pipes or in plastic U-shaped moulding, as provided in this rule, in lieu of the grounded iron or steel pipe required by this rule, provided that risers of circuits in excess of 750 volts shall have an effectively grounded metallic shield. Such plastic pipe shall be of material as specified in Rule 22.2-C, designated as EPC-80-pvc with a minimum nominal pipe size of 2 ½ inches.Such plastic pipe shall be of material as specified in Rule 22.2-D, designated as EPC-80-PVC with a minimum nominal pipe size of 2 ½ inches. Such plastic pipe shall be of material as specified in Rule 22.2-C with a minimum nominal pipe size of 1 inch and with a minimum impact strength equal to 2-½” nominal EPC-80-PVC plastic pipe and installed with a backup plate of polyvinyl chloride material.

Any riser on the surface of a pole or not more than 18 inches from the center line of a pole shall be covered by a suitable protective covering where within a vertical distance of 8 feet from the level of communication conductors (including cables) or unprotected supply conductors (including the leads from the terminal) supported by the same pole or where within a radial distance of 6 feet from conductors not supported by the same pole.

Any riser more than 18 inches from the center line of a pole shall be covered by a suitable protective covering, or by securely supported impregnated fiber conduit without metal pipe, where within a vertical distance of 8 feet from the level of communication conductors (including cables) or unprotected supply conductors (including the leads from the terminal) supported by the same pole or within a radial distance of 6 feet from conductors not supported by the same pole.

The portion of any riser between the insulating covering required on the upper section and the metal or plastic covering required on the lower section by the foregoing shall be covered by the extension of either or both of such coverings. Where metal pipe is used as a protective covering, the fiber conduit shall not extend within 8 feet of the ground line and shall be installed in a workmanlike manner and securely supported in order to prevent it from slipping downward and exposing any upper section of the metal pipe.

The radial clearances between conductors, specified in Table 2, Cases 16 and 17, are not required between suitably insulated conductors in the same riser.

Protective covering (suitable) is not required over risers encased in effectively grounded non-climbable metal poles or iron or steel pipe attached to a steel pole, tower or other metal structure, provided the iron or steel pipe is effectively grounded and is metallically connected to such metal structure.

The radial clearances between conductors, specified in Table 2, Cases 16 and 17, are not required between suitably insulated conductors in the same riser.