go 95 rule 58.5

Detailed Construction Requirements for Supply Lines
(Class H, L and T Circuits)

A. Circuit Voltage

Constant current series lighting circuits supplied from transformers or devices having an open circuit output voltage of more than 750 volts, except those circuits supplied from transformers or devices having a normal full-load output voltage of 750 volts or less which transformers are equipped with effective protective devices to prevent the continued existence of open-circuit voltage on the circuit, shall be classified as circuits of more than 750 volts.

Constant current series lighting circuits which conform to the specifications for circuits of 0-750 volts may be installed and treated as circuits of more than 750 volts provided any circuit so treated in any respect is consistently so treated throughout its entirety.

(1) Above Ground: No part of street lighting equipment shall be less than 20 feet above thoroughfares except for lamps supported on brackets or fixtures which do not extend more than 48 inches from the face of pole or street side of curb, in which case the clearance may be reduced to 15 feet, provided the voltage does not exceed 750 volts (see Fig. 58-5 ).

(2) Above Railways and Trolley Lines: No part of street lighting equipment which is less than 8 1/2 feet horizontally from centerline of tracks of railroads not operated by overhead trolley shall be less than 25 feet above such tracks.

No part of street lighting equipment which is less than 8 1/2 feet horizontally from the centerline of tracks or from the nearest trolley contact conductor shall be less than 4 feet above the level of the trolley contact conductor or less than 23 feet or 26 feet above running surfaces used by trolley cars or coaches depending upon the location of the contact conductors as required by Rule 74.4-B1 .

Those parts of street lighting equipment which are 8 1/2 feet or more horizontally from the centerline of any railroad track or any trolley contact conductor shall not be less than 20 feet above the surface of the thoroughfare, except as provided in Rule 58.5-B1 (see Fig. 58-5 ).

a) Messengers and Cables: All parts of street light drop wires, street lamps, and their supporting fixtures (including rods, braces and guys) shall not be less than 1 foot above or 2 feet below the level of messengers or conductors supported by messengers. These vertical clearance requirements shall not apply to those parts of such street lighting equipment which are 2 feet or more horizontally from the vertical plane of messengers, conductors supported by messengers, and metal boxes.

b) Conductors Not Supported by Messengers: All parts of street light drop wires, street lamps, and their supporting fixtures (including rods, braces and guys) shall not be less than 1 foot radially from all unprotected conductors not supported on messengers (including lead wires and taps) except the lead wires supplying the street lamps within 24 inches of their points of entrance to the street lighting equipment.

(4) From Poles: All exposed metal parts of lamps and all such parts of their supports, unless insulated from the parts carrying current, shall be maintained not less than 20 inches from the surface of wood–poles, except at pole tops. This rule shall not apply if the voltage of the circuit from which the lamp is supplied does not exceed 750 volts.

C. Lead Wires

Unprotected conductors from one level on a pole or structure to another level or to street lighting equipment shall not pass within a climbing or working space, and shall not pass through any other circuit except between pole pin positions.

Such unprotected conductors shall clear the conductors of other circuits by distances as specified in Rule 54.6-A .

Where the distance between levels is in excess of 12 feet and such unprotected conductors pass between the pole pair of conductors of any other circuit, additional supports shall be installed so that the maximum length of conductor between supports is not more than 12 feet.

Unprotected leads to street lighting equipment shall be maintained at not less than the clearances above railroads, thoroughfares and ground specified for street lighting equipment in Rule 58.5-B .

D. Insulators In Supports

Where a street lighting fixture is supported by a span wire, strain insulators shall be inserted in the span wire on both sides of the fixture not more than 9 feet nor less than 6 feet from the structures supporting the span wire; except that, where such span wire is used as a trolley for the purpose of drawing the fixture to the pole, the strain insulator at the service end may be located a distance not less than 15 inches from the centerline of pole.

Where metallic ropes or chains are used for the suspension of street lamps, said ropes or chains shall be effectively insulated from current carrying parts of equipment and of such length that when the lamp is in its normal position the lower end of the chain or rope will not be less than 8 feet from the ground, or a strain insulator shall be inserted in the free end of the rope or chain at a point not less than 7 1/2 feet from the ground when the lamp is in its normal position. Metallic ropes or chains shall be arranged so that they do not establish a metallic conducting path around a span wire sectionalizing insulator. In case this construction will not permit the lamp to be lowered sufficiently for trimming purposes, a nonmetallic rope shall be used (see Fig. 58-5 ).

Lighting units installed in the proximity of a transformer or switch shall have the following minimum radial clearances:

F. EXCEPTIONS

Lighting units supported on ornamental posts and supplied from underground sources are not included herein.