Original General Order
Detailed Construction Requirements for Supply Lines
(Class H, L
and T Circuits)
54.6 Vertical and Lateral Conductors
A. Unprotected Conductors (see Rule 20.8-D for definition)
Unprotected conductors from one level on a pole or structure to another level shall not pass within the climbing space; shall not pass within the working space, except as permitted by Rule 54.7-B2; shall not pass between the conductors of any other circuit, except between pole pin conductor positions; and shall clear the conductors of other circuits by distances not less than the following:
Highest voltage Classification Of conductors concerned
Minimum radial distance before conductors
11 ½ inches
17 ½ inches
20,000 volts and above
Where the distance between levels is in excess of 12 feet and unprotected conductors pass between the pole-pin conductor positions of any other circuit, additional supports shall be installed so that the maximum length of conductor between supports is not more than 12 feet.
The clearances in the above tabulations do not apply between taps in buckram construction, the clearances specified in Table 2, Case 16 being directly applicable.
For clearances between street light drop wires and cables, other conductors and metal boxes, See Rules 58.2-B3 and 92.1-F5
B. Ground Wires
Ground wires shall have a conductivity and Mechanical strength at least equal to that of No. 8 AWG medium-hard-drawn copper wire; they shall not be installed on the top surfaces of crossarms; and they shall have clearances of not less than 1 ½ inches from hardware in accordance with the provisions of Rules 52.7-B and 52.7-C.
Ground wires attached to or run on the face, back or underside of wood crossarms or on the surface of wood poles and structures shall be covered throughout their poles and structures protective covering (see Rule 22.2), excepting that ground wires of 0-750 volt circuits or equipment are not required to be covered where installed on the underside of crossarms or the portions of crossarms supporting 0-750 volt conductors.
Ground wires of common neutral systems are specially required to comply with the provisions of Rules 59.3-C and 59.4 in addition to the provisions of this Rule 54.6-B.
C. Lateral Conductors
Lateral runs of conductors of 0-750 volts may be less than the clearances from center line and surface of pole, and from the surface of crossarm, as specified in Table 1, Cases 8 and 9, provided such conductors are suitably insulated and placed along the bottom surface of crossarms and are protected by wood moulding on impregnated fiber conduit of thickness not less than as specified in Rule 22.2.
Lateral runs of conductors of more than 750 volts may be less than the clearances from center line and surface of pole, and from the surface of crossarms, as specified in Table 1, Cases 8 and 9, provided such conductors are suitably insulated and are protected by impregnated fiber conduit attached to the bottom surface of crossarm.
The wood moulding or fiber conduit required for protection in accordance with this Rule 54.6-C shall extend along the arm to the outer position of any conductor in the run and in no case shall the covering be terminated within 15 inches from center line of pole.
The radial clearances between conductors, specified in Table 2, Cases 16 and 17 are not required between suitably insulated conductors in the same lateral run.
D. Vertical Runs
Conductors installed in the form of vertical runs on the surface of poles or not more than 18 inches from the center line of a pole shall be suitably insulated and covered throughout by a suitable protective covering. (See Rule 22.2 for the definition of suitable protective covering) This protective covering is not required over vertical runs in metal conduit attached to metal poles, towers or other structures provided pipe and structure are metallically connected and effectively grounded.
Conductors in the form of vertical runs more than 18 inches from the center line of any pole shall be suitably insulated and covered by a suitable protective covering or by securely supported impregnated fiber conduit without metal pipe. Such runs shall be located outside of the climbing and working spaces and shall not pass between conductors of different ownership except between the pole pair and at a clearance thereform of not less than 6 inches.
Vertical runs, where encased in grounded metal conduit, sheath, or shield shall be treated as risers.
Conductors installed in the form of vertical runs which extend within 8 feet of the ground shall be enclosed in securely grounded metal casing or covering and shall be treated as risers.
The radial clearances between conductors, specified in Table 2, Cases 16 and 17, are not required between suitably insulated conductors in the same vertical run.
Risers from underground cables or other conductors shall be encased in grounded iron or steel shall (or other metal covering of equal strength) from the ground line to a level not less than 8 feet above ground line (see App. G, Fig. 61)
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.
The portion of any riser between the insulating covering required on the upper section and the metal covering required on the lower section by the foregoing shall be covered by the extension of either 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 in 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.
F. Terminals of Encased Riser and Runs
Terminals of risers or runs shall not extend above the level of line conductors to which the terminal leads are connected except as follows:
Where the line conductors are dead-ended on the opposite side of the arms from the terminals and no line conductors supported on the same crossarm and the same side of pole extend past the terminals and no buckram construction is involved, or
Where conductors in excess of 7500 volts are installed in vertical configuration on crossarms, and the terminals are mounted on the same arms which support the conductors to which the terminals are connected.
At the upper end of vertical runs or risers on wood poles, any terminal or terminal fitting within distances from center line of poles less than as specified in Table 1, Case 8, shall be protected by a crossarm or wood block placed above it at a distance not exceeding 4 inches. The wood block may be omitted if the terminal or terminal fitting at the upper end of a vertical run or riser of 750 volts or less is on the same side of a pole as, and not more than 1 foot below a transformer.
Cable or conduit bends and the terminals of riser or runs of conductors of more than 750 volts shall be arranged with as little exposed surface as practicable but are not required to be covered by a protective covering provided that no portion of the terminal or associated unprotected conductors are within the climbing space or within the clearance from center line of pole specified inTable 1, Case 8(15 or 18 inches). All exposed grounded surfaces of such terminal fittings and bends of risers and runs shall not be less than 18 inches vertically above the conductor level, and not less than 2 feet radially from any conductor at the next conductor level, of unprotected conductors of another circuit which is entirely below the level of the circuit to which the riser is connected.
The terminal fittings of risers or runs of conductors of 0-750 volts installed on the surfaces of poles shall of be within the climbing space and unprotected leads to or from such terminals shall not pass within the climbing space but may have a clearance of less than 15 inches from center line of pole (Table 1, Case 8) and less than 3 inches from the surface of pole or crossarm (Table 1, Case 9). It is recommended that conductors from such terminal fittings be suitably installed and, where practicable, carried as protected lateral runs on the bottom surface of crossarms (see Rule 54.6-C)
The Vertical clearances between the lowest point of lead wires of a riser or run (vertical or lateral) and the next conductor level below shall conform to the requirements specified in Rule 54.4-C6.
See App. G, Fig. 61
G. Clearance From Hardware on Wood Poles or Structures
On wood pole or structures, all ground wires, conductor sheaths (metallic or nonmetallic braids, tapes, or coverings), metal conduit of risers or runs, and hardware used for attaching such risers or runs to structures, shall be not less than 1 ½ inches from guy shims, bolts, braces, pole steps, and other hardware not associated with the risers or runs. In cases where it is not practicable to obtain at least 1 ½ inches of air-gap and creepage distance, suitable insulating sheet fiber or fiber conduit or other suitable means shall be used to provide a creepage distance of not less than 1 ½ inches.
H. Attachment of Protective Covering
Protective covering shall be attached to pole, crossarms, or structures by means of corrosion-resisting metal straps or staples which are adequate to maintain such covering in its proper position. The distance between straps or staples shall not exceed 3 feet where such covering is a hardwood moulding. Due care shall be exercised to avoid the possibility of nails protruding through any inner surface of any wood casing used as a protective covering.