SU25 GO95 rule 58

Traffic signals supported on overhead suspensions shall be treated as specified in the following rules:

The suspension messenger or span wire of all traffic signals shall be installed to afford the clearances prescribed for span wires; Table 1, Column A and Table 2, Column A.

Lead Wires of 0-750 volts to traffic signals supported on messengers may be less than the clearances above ground specified in Table 1, Column D, Cases 2 and 3 provided they are maintained at a clearance above ground as specified in Table 1, Column A, Cases 2 and 3 for the messenger on which they are supported.

Traffic signals supported by span wires and supplied from circuits of 0-750 volts shall have a clearance of not less than 14 feet vertically above thoroughfares over which they are suspended (see App. G, Fig. 55) except that where any thoroughfares is used by railroads, street railways, trolley coach lines and double deck motor coaches clearances not less than the following shall be maintained:

Conveyance using thoroughfare	Minimum clearance of signal above thoroughfare
Street railways and coach lines operated by overhead trolley--------------------------	Height of trolley conductor plus 1 foot (a)
Railroads which transport freight cars----	25 feet (b)
Double deck motor coaches	18 feet

a) May be reduced to 14 feet if the signal is more than 8 � feet from nearest trolley contact conductor and if signal is maintained not less than 1 foot radially from trolley span wires.

b) May be reduced to 14 feet if signal is more than 8 � feet from center line track.

Traffic signals supplied directly (without protective transformers) from circuits classified in excess of 750 volts shall be install with clearances as prescribed for street lighting equipment.

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 clearances may be reduced to 15 feet, provided the voltage does not exceed 750 volts (see App, G, Fig. 56).

(2) Above Railways and Trolley Lines: No part of street lighting equipment which is less than 8 � feet horizontally from center line 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 � feet horizontally from center line 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 above 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 � feet or more horizontally from center line of any railroad track or any trolley contact conductor shall be not less than 20 feet above the surface of the thoroughfare, except as provided in Rule 58.2-B1 (see App. G, Fig. 56).

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 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 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 structure to another level or to street lighting equipment shall not pass within a climbing or working space, and 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 58.2-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 of not less than 15 inches from the center line 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 ground, or a strain insulator shall be inserted in the free end of the rope or chain at a point not less than 7 � feet from the ground when the lamp is in its normal operation. Metallic ropes or chains shall be arranged so that they do not establish a metallic conducting path around a span wire-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 App. G, Fig. 56.

E. Lighting Units on Transformer Poles

Where a lamp is installed above a transformer or switch, a minimum vertical separation of 4 feet from any portion of the transformer or switch and the lighting unit shall be maintained.

Where a lamp is installed below a transformer, any portion of the lighting equipment shall clear all supply equipment a minimum distance of 1 foot.

F. Cutouts

Suitable devices shall be provided by which each street lamp on series circuits of more than 750 volts may be safely and entirely disconnected from the circuit, before the lamps are handled, unless the lamps are worked on from wood poles or from suitable insulating stools, platforms or tower wagons. Exempted from this provision are lamps such as incandescent lamps which in themselves present a noncurrent-carrying surface which may be utilized as a handle in removing them from their support.

F. Exceptions

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

A. Position on Pole

Where more than one transformer is installed on a pole, all transformers shall be placed on the same side of pole.

Transformers shall not be supported on pole top extensions.

a) Lead and bus wires: The clearances above ground specified in Table 1 are applicable to unprotected lead and bus wires of transformer installations except as modified by the following provisions.

Clearances above ground unprotected lead and bus wires of transformer installations may be less than 25 feet as specified in Table 1, Column E case 3 and 4, but shall not be less than 22 � feet except where a clearance of not less than 18 feet above ground is permitted by the provisions of Rule 54.4-A2b in which case the clearance above ground of such lead and bus wires shall be not less than 18 feet,

Clearances above ground of unprotected lead and bus wires of transformer installations may be less than 30 feet as specified in Table 1, Column F, Cases 3 and 4, but shall be not less than 27 feet.

Clearances above ground of unprotected lead and bus wires of transformer installations on structures of two or more poles may be less than 22 � feet or 27 feet as specified above, or less than 25 feet as specified in Table 1, Column F, Case 5 but shall not be less than 20 feet above ground, provided such lead or bus wires are guarded by transformer platform flooring which extends not less than 1 foot horizontally outside the vertical planes of all such lead and bus wires on the structure.

b) Cases: Cases of transformers supported on poles or structures shall not be less than 17 feet above the ground except that in areas which are not in any way accessible to vehicles, the clearance of cases above ground shall be effectively grounded.

(2) From Buildings: Transformers on poles shall be so located that normally Unenergized parts clear the surfaces of buildings by not less than 3 feet horizontally or by not less than 8 feet vertically. Lead and bus wires carried as unprotected conductors shall have the clearances from buildings as specified in Table 1, Cases 6 and 7.

In situations where foregoing clearances of cases and lead bus wires from walls of buildings (not windows, fire escapes, etc.) are impracticable to obtain, such as the location of transformers on poles in alleys, these clearances will not be held applicable provided wood barriers authorized by this Commission are used.

(3) Cases from conductor levels above and below: Transformers shall be so installed that normally Unenergized metal parts clear unprotected conductors, except the transformer connecting leads by distances specified in the following provisions:

a) From 0-750 volt conductors below: The vertical clearance of transformer cases and hangers from the level of 0-750 volt conductors below (whether such conductors are supported on crossarms or racks) shall not be less than 10 inches except for certain conductors as provided in Rule 58.3-B4.

b) From 0-750 volt conductors above: The vertical clearance of Unenergized metal parts of transformers from 0-750 volt conductors supported on crossarms above shall be not less than 3 inches or, in lieu of such vertical clearance, the Unenergized parts of transformers shall not be less than 6 inches horizontally from such conductors. The vertical clearance of unenergized metal parts of transformers from 0-750 volt conductors supported on racks above shall be not less than 4 feet.

c) From 750-7500 volt conductors below: The vertical clearance of Unenergized metal parts of transformers from the level of 750-7500 volt conductors below shall be not less than 12 inches.

d) From 750-7,500 Volt Conductors Above: The clearance between un-energized metal parts of transformers and 750-7,500 volt conductors above or alongside shall be not less than 12 inches vertically or 12 inches horizontally, except that conductors of the circuit to which the transformer is connected may be less than the 12-inch vertical clearance from such un-energized parts but shall be not less than 6 inches vertically from the transformer case and not less than 3 inches radially from the hanger provided no line conductor which is less than 12 inches horizontally from the case or hanger is less than 3 inches (Table 1, Case 9) above the level of the top surface of the crossarm.

EXCEPTION: The vertical clearance shall not be less than 30 inches from the conductor at the top of pole as in Rule 54.4-D8.

e) From 7,500-22,500 Volt Conductors Above: The clearance between un-energized metal parts of transformers and 7,500-22,500 volt conductors above shall be not less than 18 inches vertically or 18 inches horizontally.

EXCEPTION: The vertical clearance shall not be less than 30 inches from a conductor at the top of pole as in Rule 54.4-D8.

(4) Transformer Cases from Certain Conductors Less than 10 inches below the cases

a) Transformer Leads on Heel Arms: Heel arms shall not used to support lead wires or taps except where necessary to clear the lower voltage transformer leads from the transformer case or other conductors.

b) Line conductors less than 10 inches below cases: Where a transformer case is unusually long, a crossarm supporting line conductors of 0-750 volts may be used as a heel arm or such conductors on an arm may be less than 10 inches below the transformer case or the hangers) provided all of the following conditions are met:

No more than a single transformer with lower voltage of 0-750 volts is supported on the pole at the same level;

The vertical clearances between conductors on the hanger arm and such line arm below shall not be less than as specified in Table 2, Cases 9 to 13;

It is not practicable to obtain the clearance of at least 10 inches specified in Rule 58.3-B3;

Such 0-750 volt conductors clear the transformer case by not less than 15 inches horizontally;

Service drops are not run from the crossarm supporting 0-750 volts conductors at that location; and

The vertical clearance of 0-750 volt conductors below the lowest point of the transformer primary leads is not less than

(5) From Hardware: Transformer cases, hangers, and other metal parts in contact therewith shall clear through bolts, arm braces and other hardware by not less than 1 � inches; except that transformer cases and hangers shall clear crossarm braces and crossarm through bolts by not less than 1-inch air-gap distances and 1 � �inch creepage distance.

The minimum clearance of 1 � inches need not apply to through bolts in metallic contact with transformer cases or metal parts thereof nor to through bolts supporting heel arms, provided the portion of such through bolts extending into the climbing space is covered with a suitable protective covering, and provided that such coverings are made of seasoned Douglas Fir and are installed in a workmanlike manner, or in the alternative, with a suitable nonconducting shield or covering having the insulation efficiency and mechanical strength of impregnated fiber 5/16 inches thick.

(6) From Guys: Transformer cases and hangers shall be not less than 4 inches from all portions of guys which are 6 inches or more from the surface of poles or crossams at the guy attachment. Transformer cases and hangers shall be not less than 1 � inches from all portions of guys which are within 6 inches of the surface of poles or crossarms at the guy attachments.

(7) Treatment of lead wires: Vertical and lateral leads between line conductors and transformers shall comply with Rule 54.6 and 54.4-C6; and with the clearances specified in Table 1, Cases 8 and 9; and Table 2, Cases 15, 16 and 17. Where such leads enter cutouts or switches Rule 58.5-C shall also apply. Such lead wires may be installed in the climbing space.

The clearances specified in Table 1, Case 8, Column D and E need not apply to apparatus installed on poles consisting of single pole structures or on crossarms attached thereto provided that terminals and lead wires are not less than 6 inches from surface of pole instead of 3 inches specified in Table 1, Case 9, Columns D and E, and have as much possible of the clearance specified in Table 1, Case 8 Columns D and E, is permitted for interconnection wiring of polyphase installations nor to connection wiring of polyphase installations nor to any lead wire passing between pole apparatus.

All lead wires shall clear braces, bolts and other line hardware a distance of not less than 1 � inches.

(1) Grounding of Windings: Transformer windings not exceeding 250 volts (except those exclusively for energizing street lighting circuits and those used exclusively for energizing signal and track circuit) shall be effectively grounded as follows:

a) Single phase systems: In two wire (nominal 120-volt system one wire shall be grounded; in two wire (nominal 240-volt) systems where the mid-point or some intermediate point of the windings is not available, one wire shall be grounded; in two-wire (nominal 240 volt) systems where the mid-point or some intermediate point of the winding is available, that point shall be grounded; in three-wire (nominal 120/240-volt) systems, the mid-point of the winding shall be grounded. (See App. G, Fig 57.)

b) Two phase systems: In three-wire (nominal 240 volt) systems, the point common to both windings shall be grounded; in four-wire (nominal 120/240-volt) systems, the mid-point of the winding on one phase shall be grounded; in four wire (nominal 240-volt), and five wire (nominal 120/240-votls) systems, the mid-points of both windings shall be connected and grounded. (See App. G, Fig. 58.)

c) Three-Phase Systems: In three-wire delta (nominal 120 or 240 volt) systems the midpoint of one transformer winding or, a point common to two windings (one phase wire) shall be grounded; in three-wire star (nominal 120 208or 240 volt) systems, the point common to all windings or, one of the phase wires shall be grounded; in four-wire star (nominal 120/208 volt) systems, the common point shall be grounded (see App. G, Fig. 59).

d) Where the Secondary system is grounded at any point, the grounded conductor shall be run to each service.

(2) Location of Transformer Winding Grounds: Transformer ground connections shall be provided at one of the following locations:

AT the load end of each service supplied from the transformer, separate from the usual house ground, except that where three or more services are supplied from one transformer or bank of transformers, ground connections at the two services nearest the transformer pole and one ground connection at services at approximately 500-foot intervals will suffice.

Transformer ground connections other than those occurring on common primary and secondary grounded neutral systems shall have a conductivity not less than that of No. 6 AWG copper wire.

Where a common primary and secondary grounded neutral system is used, ground connections shall conform to the requirements of Rule 59.4-A.

(3) Transformer Case Grounding or Bonding: Cases of transformers and metal parts in contact therewith shall not be grounded where supported on wood poles or wood structures.

Except in the case of partial underground distribution systems (see Rule 21.13),the hanging or placing of transformers on metal poles or structures is not recommended, particularly with respect to transformers connected to circuits of less than 14,000 volts. Transformers shall not be supported on metal poles or metal supports in contact with the ground unless the cases are securely bonded to the metal poles or parts of structures in contact with the ground and such poles or structures are effectively grounded. No transformer case shall be in contact with a metal support (crossarm, metal beam. metal bracket) attached to a wood pole or a wood structure, excepting when no portion of a transformer case or its metal support extends beyond a vertical plane through the center line of pole.

The bonding of cases of transformers whose high voltage windings are connected to circuits of less than 20,000 volts is not recommended but where such cases are bonded the case bonding system shall not be electrically connected to any unassociated hardware or to other bonds.

Except from the provisions of this Rule 58.3-C3 applying to the grounding of transformer cases supported on wood poles or structures are the following:

Any transformer whose high-voltage winding is connected to a circuit of more than 14,000 volts, which may have its case grounded provided all such transformer installations on the system are so grounded, warning signs calling attention to the case grounding condition are posted on the structure so as to be readily legible from the climbing space or spaces, and no such grounded transformer case is less than 8 feet vertically or 4 feet horizontally from the unprotected conductors of any other supply-line circuit than those to which the transformer windings are connected;

Any transformer whose high-voltage is connected to a circuit of 750-14,000 volts, which may have its case grounded provided no unprotected conductors (including lead wires) of 750-14,000 volts shall be less than 8 feet vertically or 4 feet horizontally from the nearest part of such grounded case; and

Transformer cases which are grounded in accordance with any provision of this rule shall be effectively grounded (see Rule 33.3).

D. Cutouts or Other Disconnecting Devices

Transformer cutouts, fuses, disconnects or switches shall be located so that they are readily accessible from climbing and working spaces. Such devices or their connecting leads shall not extend into the climbing space but may extend wholly or in part into the working space.

The vertical clearances of transformer cutouts, fuses, etc., above the levels of conductors of other circuits shall not less than the clearances required between conductors as specified in Table 2, Cases 8 to 13.

The provisions of this rule shall not apply to partial underground distribution systems.

E. Connections Between Windings

Any metallic connection between the primary and secondary windings of a distribution transformer (as in common neutral systems) shall be made externally and not within the transformer case.

A. Position on Pole

Where more than one capacitor or regulator is installed on a pole, all capacitors or regulators shall be placed on the same side of the pole. Excepted from this requirement are capacitors which may be installed on opposite sides of a pole between the two arms of a double arm provided no transformers, regulators, or oil switches are installed on the same pole.

Capacitors or regulators shall not be installed on pole top extensions.

(1) Above ground: Any capacitor or regulator shall be so located that the bottom of the case and associated metal parts shall not be less than 17 feet above ground. The clearances above ground of leads to such apparatus shall conform to the requirements of Rule 58.3-B1a.

(2) From Buildings: Capacitors or regulators shall be so located that normally unenergized parts clear the surfaces of buildings by not less than 3 feet horizontally or by not less than 8 feet vertically. Lead and bus wires carried as unprotected conductors shall have the clearances from building specified in Table 1, Cases 6 and 7.

a) From 0-750 Volt Conductors Below: The vertical clearance of capacitor and regulator cases and their hangers from the level of 0-750 volt conductors below (whether such conductors are on crossarms or racks) shall not be less than 10 inches.

b) From Conductors in Excess of 750 Volts Below: The vertical clearance of capacitor and regulator cases and their hangers from the level of conductors in excess of 750 volts below shall be not less than

(4) From Hardware: Capacitor or regulator cases hangers, and other metal parts in contact therewith shall clear through bolts, arm braces of metal, and other hardware elements, by not less than 1 � inches; except that such cases shall clear crossarm braces by not less than 1-inch air-gap distance and 1 1/2 �inch creepage distance.

(5) From Guys: Capacitor or regulator cases and their hangers shall be not less than 4 inches from all portions of guys which are 6 inches or more from the surface of poles or crossarms at the guy attachments. Such cases and hangers shall be not less than 1 � inches from all portions of guys which are within 6 inches of the surface of poles or crossarms at the guy attachment.

(6) Treatment of Lead Wires: Vertical and lateral leads between line conductors and capacitors or regulators shall comply with Rules 54.6 and 54.4-C6; and with the clearances specified in Table 1, Cases 8 and 9; and Table 2, Cases 15, 16, and 17. Where such leads enter cutouts or switches, Rule 58.5-C shall also apply. Vertical and lateral leads between cutouts or fuse holders and regulator bushings, or leads directly between line conductors and such bushings may clearances less than those specified in Table 1, Case 8 Columns E and F, but not less than 6 inches from the surface of the pole; such leads shall not be over 12 inches in length. Such lead wires may be installed in the working space but shall not be installed in the climbing space.

The clearances specified in Table 1, Case 8, Columns D and E, need not apply to apparatus installed on poles consisting of single-pole structures or on crossarms attached thereto provided that terminals and lead wires are not less than 6 inches from surface of pole instead of 3 inches specified in Table 1, Case 9 Columns D and E, and have as mush possible of the clearances specified in Table 1, Case 8, Columns D and E. No reduction of the clearances specified in Table 1, Case 8, Columns D and E is permitted for interconnection wiring of polyphase installations nor to any lead wire passing between pole and apparatus.

All lead wires shall clear braces, bolts and other line hardware a distance of not less than 1 � inches.

C. Grounding and Bonding of Capacitors or Regulators

Cases of capacitors or regulators may be bonded together but shall not be bonded to cutout, metal pins, or dead-end hardware.

Cases of Capacitors shall not be grounded where such cases or any parts therof are within 8 feet vertically below, 4 feet vertically above 4 feet horizontally from any unprotected conductors.

Any capacitors or regulator which may be grounded in accordance with any provision of this rule shall be effectively grounded (see Rule 33.3).

D. Cutouts or Other Disconnecting Devices

Cutouts, fuses, disconnects or switches used in connection with capacitors or regulators shall be so located so that they are readily accessible from climbing and working spaces. Such devices or their connecting leads shall not extend into the climbing space, but may extend wholly or in part into the working space.

The vertical clearances of capacitor or regulator cutouts, fuses, etc., above the levels of conductors of other circuits shall be not less than the clearances required between conductors as specified in Table 2, Cases 8 to 13.

A. Clearance Between Energized Parts

Unenclosed switches supported on poles or pole structures shall be arranged with clearances not less than as specified in Table 2, Case 15 between the center lines of the separate phase units.

Unenclosed switches supported on poles or pole structures shall be arranged with clearances not less than as specified in Table 2, Case 17 between exposed parts which are energized from the same circuit from different phases or polarities.

B. Clearance Between Unenergized Parts and Unprotected Conductors

Metal switch cases and normally Unenergized metal parts in contact therewith shall clear all unprotected conductors, except the connecting leads, by distances as specified in Rule 58.3-B3 for Unenergized metal parts of transformers from unprotected conductors.

C. Lead Wires

Lead wires shall be suitably insulated from metal or wood cases of cutouts and switches at point of entrance thereto.

All unprotected lead wires including miscellaneous wiring shall clear brace, bolts and other line hardware a distance of not less than 1 � inches.

Where necessary at points of entrance to cutouts and switches, lead wires of 0-5000 volts may be less than 3 inches from the surface of crossarms (Table 1, Case 9, Column C, D, and E) but shall be not less than 1 inch from such surfaces.

D. Climbing and Working Space

Switches and cutouts shall be so located that, when in either the open or closed position, all energized parts thereof are not less than 15 or 18 inches from the centerline of pole as required by Table 1, Case 8, and no part of such equipment shall be in the climbing space except nonmetallic interphase shafts of gang operated switches and their associated unbonded hardware mounted at the top of the pole. See figures 58-1 and 58-2. Such apparatus is permitted to be wholly or in part within the working space. The clearances of 15 or 18 inches need not apply to nonfusable pole-top switches connected to a circuit of 7,500 volts or more, provided the switches are installed substantially in the same vertical plane as the conductors to which they are attached, and no climbing space has to be provided through and above the level of such switches.

E. Indicating Position

All enclosed switched shall indicate clearly whether they are in the open or closed position.

G. Operating Mechanism

Grounded metal operating rods which pass through conductor levels shall be protected with a suitable insulating covering for a distance of 8 feet vertically or 6 feet horizontally from communication conductors (including cables) and from unprotected supply conductors. As an alternative to this provision, metal rods shall be underground and shall have installed in them, at a point as near as possible to the switch, a suitable insulating link or section. All rods shall be securely held in position by staples or straps or other suitable means to afford clearances as specified in Table 2, Case 18 from conductors of circuits below the switch level.

All cables, ropes and other flexible means of operating switches shall have insulators installed in them at a point as close as possible to the switch and shall pass through guides to insure their separation from conductors through which they pass.

Where line switches are operated from the ground level by means of all metal control mechanisms without suitable insulating links, an insulated platform shall be provided unless such operating mechanism is effectively grounded.

A. Location and Clearances from Transformer, Capacitor or Regulator Cases

Time switches, meters and other apparatus, including their enclosures, which extend more than 5 inches from the surface of a pole shall not be installed on the surface of a pole shall not be installed on the surface of a pole supporting a transformer (or other equipment of similar dimensions), shall be not less than 4 feet above or below the nearest part of transformer case (or other equipment), unless the time switch, meter, etc., is installed on the side of the pole occupied by the transformer (or other equipment).

B. Clearance from Unprotected Conductors

On wood poles or structures, all grounded metal boxes and grounded metal cases for time switches, meters, or other apparatus shall be not less than 3 feet above or 6 feet below the level of unprotected supply conductors. Where it is impracticable to obtain a clearance of at least 6 feet below the level of unprotected supply conductors of 750 volts or less, a clearance of not less than 4 feet below such conductors will be permitted if a protective covering or guard is provided above the grounded surface.

C. Within 8 feet of the ground

Boxes or enclosures containing switches, meters, or other apparatus having accessible live parts, which are located 8 feet or less above the ground shall be effectively locked or sealed.

Metal Boxes which contain supply or control equipment or conductors and are located 8 feet or less above the ground shall be effectively grounded.

Traffic signals supported on overhead suspensions shall be treated as specified in the following rules:

A. Messengers and span wire clearances

The suspension messenger or span wire of all traffic signals shall be installed to afford the clearances prescribed for span wires; Table 1, Column A and Table 2, Column A.

B. Lead wires

Lead Wires of 0-750 volts to traffic signals supported on messengers may be less than the clearances above ground specified in Table 1, Column D, Cases 2 and 3 provided they are maintained at a clearance above ground as specified in Table 1, Column A, Cases 2 and 3 for the messenger on which they are supported.

C. Clearances above thoroughfares

Traffic signals supported by span wires and supplied from circuits of 0-750 volts shall have a clearance of not less than 14 feet vertically above thoroughfares over which they are suspended (see ~~App. G, Fig.~~ 55 Fig. 58-4) except that where any thoroughfares is used by railroads, street railways, trolley coach lines and double deck motor coaches clearances not less than the following shall be maintained:

Conveyance using thoroughfare	Minimum clearance of signal above thoroughfare
Street railways and coach lines operated by overhead trolley--------------------------	Height of trolley conductor plus 1 foot (a)
Railroads which transport freight cars----	25 feet (b)
Double deck motor coaches	18 feet

a) May be reduced to 14 feet if the signal is more than 8 � feet from nearest trolley contact conductor and if signal is maintained not less than 1 foot radially from trolley span wires.

b) May be reduced to 14 feet if signal is more than 8 � feet from center line track.

Traffic signals supplied directly (without protective transformers) from circuits classified in excess of 750 volts shall be install with clearances as prescribed for street lighting equipment.

(2) Above Railways and Trolley Lines: No part of street lighting equipment which is less than 8 � feet horizontally from center line 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 � feet horizontally from center line 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 above 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 � feet or more horizontally from center line of any railroad track or any trolley contact conductor shall be not be less than 20 feet above the surface of the thoroughfare, except as provided in Rule 58.25-B1 (see ~~App, G, Fig. 56~~ Fig. 58-6).

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 within 24 inches of their points of entrance to the street lighting equipment.

F. Cutouts

Suitable devices shall be provided by which each street lamp on series circuits of more than 750 volts may be safely and entirely disconnected from the circuit, before the lamps are handled, unless the lamps are worked on from wood poles or from suitable insulating stools, platforms or tower wagons. ~~Exempted from this provision are lamps such as incandescent lamps which in themselves present a noncurrent-carrying surface which may be utilized as a handle in removing them from their support.~~

G. Exceptions

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

~~Where more than one transformer is installed on a pole, all transformers shall be placed on the same side of pole.~~

a) Lead and bus wires: The clearances above ground specified in Table 1 are applicable to unprotected lead and bus wires of transformer installations except as modified by the following provisions.

Clearances above ground unprotected lead and bus wires of transformer installations may be less than 25 feet as specified in Table 1, Column E case 3 and 4, but shall not be less than 22 � feet except where a clearance of not less than 18 feet above ground is permitted by the provisions of Rule 54.4-A2b in which case the clearance above ground of such lead and bus wires shall be not less than 18 feet,

Clearances above ground of unprotected lead and bus wires of transformer installations may be less than 30 feet as specified in Table 1, Column F, Cases 3 and 4, but shall be not less than 27 feet.

Clearances above ground of unprotected lead and bus wires of transformer installations on structures of two or more poles may be less than 22 � feet or 27 feet as specified above, or less than 25 feet as specified in Table 1, Column F, Case 5 but shall not be less than 20 feet above ground, provided such lead or bus wires are guarded by transformer platform flooring which extends not less than 1 foot horizontally outside the vertical planes of all such lead and bus wires on the structure.

b) Cases: cases of transformers supported on poles or structures shall not be less than 17 feet above the ground except that in areas which are not in any way accessible to vehicles, the clearance of cases above ground shall be effectively grounded.

~~(2)~~ From Buildings: Transformers on poles shall be so located that normally Unenergized parts clear the surfaces of buildings by not less than 3 feet horizontally or by not less than 8 feet vertically. Lead and bus wires carried as unprotected conductors shall have the clearances from buildings as specified in Table 1, Cases 6 and 7.

In situations where foregoing clearances of cases and lead bus wires from walls of buildings (not windows, fire escapes, etc.) are impracticable to obtain, such as the location of transformers on poles in alleys, these clearances will not be held applicable provided wood barriers authorized by this Commission are used.

~~(3)~~ Cases from conductor levels above and below: Transformers shall be so installed that normally Unenergized metal parts clear unprotected conductors, except the transformer connecting leads by distances specified in the following provisions:

a) From 0-750 volt conductors below: The vertical clearance of transformer cases and hangers from the level of 0-750 volt conductors below (whether such conductors are supported on crossarms or racks) shall not be less than 10 inches except for certain conductors as provided in Rule 58.3-B4.

b) From 0-750 volt conductors above: The vertical clearance of Unenergized metal parts of transformers from 0-750 volt conductors supported on crossarms above shall be not less than 3 inches or, in lieu of such vertical clearance, the Unenergized parts of transformers shall not be less than 6 inches horizontally from such conductors. ~~The vertical clearance of unenergized metal parts of transformers from 0-750 volt conductors supported on racks above shall be not less than 4 feet.~~

c) From 750-7500 volt conductors below: The vertical clearance of Unenergized metal parts of transformers from the level of 750-7500 volt conductors below shall be not less than 12 inches.

EXCEPTION: The vertical clearance shall not be less than 30 inches from the conductor at the top of pole as in Rule 54.4-D8.

~~EXCEPTION:~~ ~~The vertical clearance shall not be less than 30 inches from a conductor at the top of pole as in Rule 54.4-D8.~~

~~(4)~~ ~~Transformer Cases from Certain Conductors Less than 10 inches below the cases~~

a) Transformer Leads on Heel Arms: Heel arms shall not used to support lead wires or taps except where necessary to clear the lower voltage transformer leads from the transformer case or other conductors.

b) Line conductors less than 10 inches below cases: Where a transformer case is unusually long, a crossarm supporting line conductors of 0-750 volts may be used as a heel arm or such conductors on an arm may be less than 10 inches below the transformer case or the hangers) provided all of the following conditions are met:

~~No more than a single transformer with lower voltage of 0-750 volts is supported on the pole at the same level;~~

~~The vertical clearances between conductors on the hanger arm and such line arm below shall not be less than as specified in Table 2, Cases 9 to 13;~~

~~It is not practicable to obtain the clearance of at least 10 inches specified in Rule 58.3-B3;~~

~~Such 0-750 volt conductors clear the transformer case by not less than 15 inches horizontally;~~

~~Service drops are not run from the crossarm supporting 0-750 volts conductors at that location; and~~

~~The vertical clearance of 0-750 volt conductors below the lowest point of the transformer primary leads is not less than~~

~~(5)~~ From Hardware: Transformer cases, hangers, and other metal parts in contact therewith shall clear through bolts, arm braces and other hardware by not less than 1 � inches; except that transformer cases and hangers shall clear crossarm braces and crossarm through bolts by not less than 1-inch air-gap distances and 1 � �inch creepage distance.

The minimum clearance of 1 � inches need not apply to through bolts in metallic contact with transformer cases or metal parts thereof nor to through bolts supporting heel arms, provided the portion of such through bolts extending into the climbing space is covered with a suitable protective covering, and provided that such coverings are made of seasoned Douglas Fir and are installed in a workmanlike manner, or in the alternative, with a suitable nonconducting shield or covering having the insulation efficiency and mechanical strength of impregnated fiber 5/16 inches thick.

(6) From Guys: Transformer cases and hangers shall be not less than 4 inches from all portions of guys which are 6 inches or more from the surface of poles or crossams at the guy attachment. ~~Transformer cases and hangers shall be not less than 1 � inches from all portions of guys which are within 6 inches of the surface of poles or crossarms at the guy attachments.~~

(7) Treatment of lead wires: Vertical and lateral leads between line conductors and transformers shall comply with Rule 54.6 and 54.4-C6; and with the clearances specified in Table 1, Cases 8 and 9; and Table 2, Cases 15, 16 and 17. ~~Where such leads enter cutouts or switches Rule 58.5-C shall also apply.~~ Such lead wires may be installed in the climbing space.

The clearances specified in Table 1, Case 8, Column D and E need not apply to apparatus installed on poles consisting of single pole structures or on crossarms attached thereto provided that terminals and lead wires are not less than 6 inches from surface of pole instead of 3 inches specified in Table 1, Case 9, Columns D and E, and have as much possible of the clearance specified in Table 1, Case 8 Columns D and E, is permitted for interconnection wiring of polyphase installations nor to connection wiring of polyphase installations nor to any lead wire passing between pole apparatus.

All lead wires shall clear braces, bolts and other line hardware a distance of not less than 1 � inches.

(1) Grounding of Windings: Where Transformer windings are grounded ~~not exceeding 250 volts (except those exclusively for energizing street lighting circuits and those used exclusively for energizing signal and track circuit)~~ they shall be effectively grounded. Where the secondary system is grounded at any point, the grounded conductor shall be run to each service. ~~as follows~~:

a) Single phase systems: In two wire (nominal 120-volt system one wire shall be grounded; in two wire (nominal 240-volt) systems where the mid-point or some intermediate point of the windings is not available, one wire shall be grounded; in two-wire (nominal 240 volt) systems where the mid-point or some intermediate point of the winding is available, that point shall be grounded; in three-wire (nominal 120/240-volt) systems, the mid-point of the winding shall be grounded. ~~(See App. G, Fig 57.)~~

b) Two phase systems: In three-wire (nominal 240 volt) systems, the point common to both windings shall be grounded; in four-wire (nominal 120/240-volt) systems, the mid-point of the winding on one phase shall be grounded; in four wire (nominal 240-volt), and five wire (nominal 120/240-votls) systems, the mid-points of both windings shall be connected and grounded. ~~(See App. G, Fig. 58.)~~

c) Three-Phase Systems: In three-wire delta (nominal 120 or 240 volt) systems the midpoint of one transformer winding or, a point common to two windings (one phase wire) shall be grounded; in three-wire star (nominal 120 208or 240 volt) systems, the point common to all windings or, one of the phase wires shall be grounded; in four-wire star (nominal 120/208 volt) systems, the common point shall be grounded (see App. G, Fig. 59).

d) ~~Where the Secondary system is grounded at any point, the grounded conductor shall be run to each service.~~

(2) Location of Transformer Winding Grounds: Transformer ground connections shall be provided at one of the following locations:

At the load end of each service supplied from the transformer, separate from the usual house ground, except that where three or more services are supplied from one transformer or bank of transformers, ground connections at the two services nearest the transformer pole and one ground connection at services at approximately 500-foot intervals will suffice.

Transformer ground connections other than those occurring on common primary and secondary grounded neutral systems shall have an ampacity ~~conductivity~~ not less than that of No. 6 AWG copper wire.

Where a common primary and secondary grounded neutral system is used, ground connections shall conform to the requirements of Rule 59.4-A.

(3) Transformer Case Grounding or Bonding: (See Rule 54.4-G for Grounded equipment clearances) Cases of transformers and metal parts in contact therewith shall not be grounded where supported on wood poles or wood structures.

Except in the case of partial underground distribution systems (see Rule 21.13),the hanging or placing of transformers on metal poles or structures is not recommended, particularly with respect to transformers connected to circuits of less than 14,000 volts.

Transformers shall not be supported on metal poles or metal supports in contact with the ground unless the cases are securely bonded to the metal poles or parts of structures in contact with the ground and such poles or structures are effectively grounded. ~~No transformer case shall be in contact with a metal support (crossarm, metal beam. metal bracket) attached to a wood pole or a wood structure, excepting when no portion of a transformer case or its~~ installed on metal s~~upport extends beyond a~~ mounting bracket shall not extend beyond the vertical plane through the center line of the pole.

Where transformer cases are bonded, the case bonding system shall not be electrically connected to any unassociated hardware or to other bonds.

The bonding of cases of transformers whose high voltage windings are connected to circuits of less than 20,000 volts is not recommended but where such cases are bonded the case bonding system shall not be electrically connected to any unassociated hardware or to other bonds.

Except from the provisions of this Rule 58.3-C3 applying to the grounding of transformer cases supported on wood poles or structures are the following:

Any transformer whose high-voltage winding is connected to a circuit of more than 14,000 volts, which may have its case grounded provided all such transformer installations on the system are so grounded, warning signs calling attention to the case grounding condition are posted on the structure so as to be readily legible from the climbing space or spaces, and no such grounded transformer case is less than 8 feet vertically or 4 feet horizontally from the unprotected conductors of any other supply-line circuit than those to which the transformer windings are connected;

Any transformer whose high-voltage is connected to a circuit of 750-14,000 volts, which may have its case grounded provided no unprotected conductors (including lead wires) of 750-14,000 volts shall be less than 8 feet vertically or 4 feet horizontally from the nearest part of such grounded case; and

Any transformer the case of which is less than 8 feet above the ground.

Transformer cases which are grounded in accordance with any provision of this rule shall be effectively grounded (see Rule 33.3).

D. Cutouts or Other Disconnecting Devices

Transformer cutouts, fuses, disconnects or switches shall be located so that they are readily accessible from climbing and working spaces. Such devices or their connecting leads shall not extend into the climbing space but may extend wholly or in part into the working space.

The vertical clearances of transformer cutouts, fuses, etc., above the levels of conductors of other circuits shall not less than the clearances required between conductors as specified in Table 2, Cases 8 to 13.

The provisions of this rule shall not apply to partial underground distribution systems.

EB. Connections Between Windings

Any metallic connection between the primary and secondary windings of a distribution transformer (as in common neutral systems) shall be made externally and not within the transformer case.

58.41 ~~Capacitors And Voltage Regulators~~ Enclosed Equipment (Transformer, Capacitors, Regulators)

(1) Multiple Units: Where more than one unit capacitor or regulator is installed on a pole, all capacitors or regulators they shall be placed on the same side of the pole. Excepted from this requirement are capacitors which may be installed on opposite sides of a pole between the two arms of a double arm provided no transformers, regulators, or oil switches are installed on the same pole.

(2) Pole tope extensions: ~~Capacitors or regulators~~ Equipment shall not be installed on pole top extensions.

EXCEPTION: Pole top extensions that conform with strength requirements for a whole pole (see Rule 49.1�A ) may be used to support equipment.

~~(1) Above ground:~~ ~~Any capacitor or regulator shall be so located that the bottom of the case and associated metal parts shall not be less than 17 feet above ground.~~ ~~The clearances above ground of leads to such apparatus shall conform to the requirements of Rule 58.3-B1a.~~

~~(2) From Buildings:~~ ~~Capacitors or regulators shall be so located that normally unenergized parts clear the surfaces of buildings by not less than 3 feet horizontally or by not less than 8 feet vertically.~~ ~~Lead and bus wires carried as unprotected conductors shall have the clearances from building specified in Table 1, Cases 6 and 7.~~

~~a) From 0-750 Volt Conductors Below:~~ The vertical clearance of capacitor and regulator cases and their hangers from the level of 0-750 volt conductors below (whether such conductors are on crossarms or racks) shall not be less than 10 inches.

~~b) From Conductors in Excess of 750 Volts Below:~~ ~~The vertical clearance of capacitor and regulator cases and their hangers from the level of conductors in excess of 750 volts below shall be not less than~~

(2) Cases above Ground: Cases of equipment supported on poles or structures shall be not less than 17 feet above the ground except that in areas which are not in any way accessible to vehicles, the clearance of cases above ground may be less than 17 feet provided all cases which are less than 8 feet above ground shall be effectively grounded.

(43) From Hardware: ~~Capacitor or regulator~~ Equipment cases hangers, and other metal parts in contact therewith shall clear through bolts, arm braces of metal, and other hardware elements, by not less than 1.5 � inches; except that such cases and hangers shall clear crossarm and crossarm through bolts braces by not less than 1-inch air-gap distance and 1.5 � �inch creepage distance.

The minimum clearance of 1.5 inches need not apply to through bolts in metallic contact with equipment cases or metal parts thereof nor to through bolts supporting heel arms, provided the portion of such through bolts extending into the climbing space is covered with non�conducting material as specified in Rule 22.2 .

(54) From Guys: ~~Capacitor or regulator~~ Equipment cases and their hangers shall be not less than 4 inches from all portions of guys which are 6 inches or more from the surface of poles or crossarms at the guy attachments. Such cases and hangers shall be not be less than 1.5 � inches from all portions of guys which are within 6 inches of the surface of poles or crossarms at the guy attachment.

(61) Unprotected Case and Lead Wire Clearances ~~Treatment of Lead Wires:~~ Unprotected Vertical and lateral leads between line conductors and ~~capacitors or regulators~~ equipment shall comply with Rules 54.6 and 54.4-C6; and with the clearances specified in Table 1, Cases 8 and 9; and Table 2, Cases 15, 16, and 17. Where such leads enter cutouts or switches, Rule 58.5-C shall also apply. Vertical and lateral leads between cutouts or fuse holders and regulator bushings, or leads directly between line conductors and such bushings may clearances less than those specified in Table 1, Case 8 Columns E and F, but not less than 6 inches from the surface of the pole; such leads shall not be over 12 inches in length. Such lead wires may be installed in the working space but shall not be installed in the climbing space.

The clearances specified in Table 1, Case 8, Columns D and E, need not apply to apparatus installed on poles consisting of single-pole structures or on crossarms attached thereto provided that terminals and lead wires are not less than 6 inches from surface of pole instead of 3 inches specified in Table 1, Case 9 Columns D and E, and have as mush possible of the clearances specified in Table 1, Case 8, Columns D and E. No reduction of the clearances specified in Table 1, Case 8, Columns D and E is permitted for interconnection wiring of polyphase installations nor to any lead wire passing between pole and apparatus.

~~All lead wires shall clear braces, bolts and other line hardware a distance of not less than 1 � inches.~~

CF. ~~Grounding and~~ Bonding ~~of Capacitors or Regulators~~

Cases of ~~capacitors or regulators~~ equipment may be bonded together but shall not be bonded to cutout, metal pins, or dead-end hardware.

Cases of Capacitors shall not be grounded where such cases or any parts therof are within 8 feet vertically below, 4 feet vertically above 4 feet horizontally from any unprotected conductors.

Any capacitors or regulator which may be grounded in accordance with any provision of this rule shall be effectively grounded (see Rule 33.3).

DC. Equipment Cutouts or Other Equipment Disconnecting Devices

Equipment Cutouts, fuses, disconnects or switches ~~used in connection with capacitors or regulators~~ shall be so located so that they are readily accessible from climbing and working spaces. Such devices or their connecting leads shall not extend into the climbing space, but may extend wholly or in part into the working space.

The vertical clearances of capacitor or regulator cutouts, fuses, etc., above the levels of conductors of other circuits shall be not less than the clearances required between conductors as specified in Table 2, Cases 8 to 13.

The vertical clearance between equipment cutouts, fuses, disconnects or switches and unprotected conductors of other circuits below shall not be less than the clearances required between conductors as specified in Table 2, Cases 8 to 13.

The horizontal clearance between equipment cutouts, fuses, disconnects or switches and unprotected conductors of different phase or polarity shall not be less than the clearances specified in Table 2, Case 17.

The provisions of this rule shall not apply to partial underground distribution systems.

(a) May be reduced to 20 feet provided such lead or bus wires are guarded by transformer platform flooring which extends not less than 1 foot horizontally outside the vertical planes of all such lead and bus wires.

(b) May be reduced under special conditions: Supply conductors of 750 - 7,500v see Rule 54.4�H1 .

(c) If less than 6 feet below a walkable surface must have 6 foot horizontal clearance until vertical clearance is obtained.

(b) For clearances from connecting lead wires and cases, see Table 2, Case 17

(c) For conductors supported by rack construction, this dimension shall be a minimum of 4 feet.

(d) May be reduced to 3 inches radially from unenergized cases and hangers, provided no line conductor which is less than 12 inches horizontally from the case or hanger is less than 3 inches above the level of the top surface of the crossarm.

Line switches and line disconnects shall be located so that they are readily accessible from climbing and working spaces. Such devices or their connecting leads shall not extend into the climbing space but may extend into the working space.

A. ~~Clearance Between Energized Part~~s Unenclosed

~~Unenclosed switches supported on poles or pole structures shall be arranged with clearances not less than as specified in Table 2, Case 15 between the center lines of the separate phase units.~~

(1) Vertical clearances between exposed energized parts of line switches and line disconnects (including fused and unfused line cutouts) and unprotected conductors of other circuits above and below shall not be less than the clearances specified by Table 2, Cases 8 to 13 .

Clearances between exposed parts of line switches and line disconnects (including fused or unfused line cutouts) which are energized from the same circuit, from exposed parts of different phases or polarities shall not be less than the clearances specified by Table 2, Case 17.

Unenclosed switches supported on poles or pole structures shall be arranged with clearances not less than as specified in Table 2, Case 17 between exposed parts which are energized from the same circuit from different phases or polarities.

B. Clearance Between Unenergized Parts and Unprotected Conductors

Metal switch cases and normally Unenergized metal parts in contact therewith shall clear all unprotected conductors, except the connecting leads, by distances as specified in Rule 58.3-B3 for Unenergized metal parts of transformers from unprotected conductors.

(2) Lead wires shall be suitably insulated from ~~metal or wood~~ cases of cutouts and switches at point of entrance thereto.

All unprotected lead wires including miscellaneous wiring shall clear brace, bolts and other line hardware a distance of not less than 1.5 � inches.

Where necessary at points of entrance to cutouts and switches, lead wires of 0-5000 volts may be less than 3 inches from the surface of crossarms (Table 1, Case 9, Column C, D, and E) but shall be not be less than 1 inch from such surfaces.

(3) Switches and cutouts shall be so located that, when in either the open or closed position, all energized parts thereof are not less than 15 or 18 inches from the centerline of pole as required by Table 1, Case 8, and no part of such equipment shall be in the climbing space except nonmetallic interphase shafts of gang operated switches and their associated unbonded hardware mounted at the top of the pole. See figures 58-12 and 58-23. Such apparatus is permitted to be ~~wholly or in part~~ within the working space. The clearances of 15 or 18 inches need not apply to nonfusable pole-top switches connected to a circuit of 7,500 volts or more, provided the switches are installed substantially in the same vertical plane as the conductors to which they are attached, and no climbing space has to be provided through and above the level of such switches.

B. Enclosed Switches

All enclosed switched shall indicate clearly whether they are in the open or closed position.

(1) Grounded metal operating rods which pass through any supply or communication conductor levels shall be protected with a suitable ~~insulating~~ protective covering for a vertical distance of 8 feet ~~vertically~~ above and below or 6 feet horizontally from such levels ~~communication conductors (including cables) and from unprotected supply conductors.~~ ~~As an alternative to this provision,~~

(2) Ungrounded metal operating rods which pass through supply or communication conductor level shall: ~~be underground and shall~~

a) have a suitable insulating link or section installed ~~in them~~, at a point as near as possible to the switch,; and a

b) have a suitable insulating link or section installed at a point between each conductor level through which it passes.

(3) All operating rods shall be securely held in position by ~~staples or straps or other~~ a suitable means to afford clearances as specified in Table 2, Case 18 from conductors of circuits below the switch level.

All cables, ropes and other flexible means of operating switches shall have insulators installed in them at a point as close as possible to the switch and shall pass through guides to insure their separation from conductors through which they pass.

(4) Where line switches are operated from the ground level by means of all metal control mechanisms without suitable insulating links or sections, an insulated platform shall be provided unless such operating mechanism is effectively grounded.

58.6 Time Switches, Meters, Metal Boxes, ~~and~~ Other Apparatus and Associated Antennas

A. ~~Location and Clearances from Transformer, Capacitor or Regulator Cases~~ Grounded (see Rule 54.4-G)

Time switches, meters and other apparatus, including their enclosures, which extend more than 5 inches from the surface of a pole shall not be installed on the surface of a pole shall not be installed on the surface of a pole supporting a transformer (or other equipment of similar dimensions), shall be not less than 4 feet above or below the nearest part of transformer case (or other equipment), unless the time switch, meter, etc., is installed on the side of the pole occupied by the transformer (or other equipment).

B. ~~Clearance from Unprotected Conductors~~ Ungrounded

Time switches, meters, metal boxes, other apparatus and associated antennas are not allowed in the climbing space.

On wood poles or structures, all grounded metal boxes and grounded metal cases for time switches, meters, or other apparatus shall be not less than 3 feet above or 6 feet below the level of unprotected supply conductors. Where it is impracticable to obtain a clearance of at least 6 feet below the level of unprotected supply conductors of 750 volts or less, a clearance of not less than 4 feet below such conductors will be permitted if a protective covering or guard is provided above the grounded surface.

(1) Multiple Units: Where more than one unit is installed on a pole, they shall be placed on the same side of the pole.

(2) Pole Top Extensions: Equipment shall not be supported on pole top extensions.

EXCEPTION: Pole top extensions that conform with strength requirements for a whole pole (see Rule 49.1�A ) may be used to support equipment.

(1) Unprotected Lead Wire Clearances: Unprotected vertical and lateral leads between line conductors and equipment shall comply with Rules 54.6 and 54.4�C6 ; and with the clearances specified in Table 1, Cases 8 and 9 ; and Table 2, Cases 15, 16 and 17 . Such lead wires may be installed in the working space but shall not be installed in the climbing space.

The clearance specified in Table 1, Case 8, Columns D and E , need not apply to apparatus installed on poles consisting of single�pole structures or on crossarms attached thereto, provided that terminals and lead wires are not less than 6 inches from surface of pole instead of 3 inches specified in Table 1, Case 9, Columns D and E , and have as much as possible of the clearances specified in Table 1, Case 8, Columns D and E. No reduction of the clearances specified in Table 1, Case 8, Columns D and E is permitted for interconnection wiring of polyphase installations nor to any lead wire passing between pole and apparatus.

(3) From Hardware: Equipment cases, hangers, and other metal parts in contact therewith shall clear through bolts, arm braces of metal, and other hardware elements, by not less than 1.5 inches; except that such cases and hangers shall clear crossarm braces and crossarm through bolts by not less than 1 inch air�gap distance and 1.5 inch creepage distance.

The minimum clearance of 1.5 inches need not apply to through bolts in metallic contact with equipment cases or metal parts thereof nor to through bolts supporting heel arms, provided the portion of such through bolts extending into the climbing space is covered with non�conducting material as specified in Rule 22.2 .

(4) From Guys: Equipment cases and their hangers shall not be less than 4 inches from all portions of guys which are 6 inches or more from the surface of poles or crossarms at the guy attachments. Such cases and hangers shall not be less than 1.5 inches from all portions of guys which are within 6 inches of the surface of poles or crossarms at the guy attachment.

C. Equipment Cutouts or Other Equipment Disconnecting Devices

Equipment cutouts, fuses, disconnects or switches shall be located so that they are readily accessible from climbing and working spaces. Such devices or their connecting leads shall not extend into the climbing space, but may extend into the working space.

The vertical clearance between equipment cutouts, fuses, disconnects or switches and unprotected conductors of other circuits below shall not be less than the clearances required between conductors as specified in Table 2, Cases 8 to 13 .

The horizontal clearance between equipment cutouts, fuses, disconnects or switches and unprotected conductors of different phase or polarity shall not be less than the clearances specified in Table 2, Case 17 .

The provisions of this rule shall not apply to partial underground distribution systems.

F. Bonding

Cases of equipment may be bonded together but shall not be bonded to cutouts, metal pins or deadend hardware.

Table 58�1 Unprotected Bus and Lead Wire Clearances
Case	Nature of Clearance	Clearances Required
Case	Nature of Clearance	750 Volts - 22.5 kV	22.5 kV & above
Above Ground
1	Single Pole Structure	22.5 Feet	27.0 Feet
2	Two or More Pole Structure	22.5 Feet (a)	27.0 Feet (a)
From Buildings - Horizontal From Building Walls
3	With Windows, Fire Escapes, etc.	6.0 Feet (b)	6.0 Feet
4	Without Windows, Fire Escapes, etc.	1.0 Foot (c)	1.0 Foot
From Building - Vertical above
5	Walkable Surfaces	12.0 Feet	12.0 Feet
6	Non�Walkable Surfaces	8.0 Feet	8.0 Feet

(b) May be reduced under special conditions: Supply conductors of 750 - 7,500v see Rule 54.4�H1 .

(c) If less than 6 feet below a walkable surface must have 6 foot horizontal clearance until vertical clearance is obtained.

Table 58�2 Ungrounded Cases from Line Conductors (a) (b)
Line Conductors		Comm.	0 - 750 Volts	750 - 7500 Volts	7500V - 22.5KV	22.5 kV & above
1	Vertical above Case	48 in.	3 in.(c)	12 in.(d)	18 in. (e)	24 in.
2	Vertical below Case	48 in.	10 in.(d)	12 in.(d)	18 in. (e)	24 in.
3	Horizontal from Case	N/A	6 in.	12 in.	18 in.	24 in.

(b) For clearances from connecting lead wires and cases, see Table 2, Case 17 .

(c) For conductors supported by rack construction, this dimension shall be a minimum of 4 feet.

(1) Grounding of Windings: Where transformer windings are grounded, they shall be effectively grounded. Where the secondary system is grounded at any point, the grounded conductor shall be run to each service.

(2) Location of Transformer Winding Grounds: Transformer ground connections shall be provided at one of the following locations:

Transformer ground connections other than those occurring on common primary and secondary grounded neutral systems shall have an ampacity not less than that of No. 6 AWG copper wire.

Where a common primary and secondary grounded neutral system is used, ground connections shall conform to the requirements of Rule 59.4�A .

(3) Transformer Case Grounding or Bonding: (See Rule 54.4�G for Grounded Equipment Clearances)

Transformers shall not be supported on metal poles or metal supports in contact with the ground unless the cases are securely bonded to the metal poles or parts of structures in contact with the ground and such poles or structures are effectively grounded. Transformers installed on metal mounting brackets shall not extend beyond the vertical plane through the centerline of the pole.

Where transformer cases are bonded, the case bonding system shall not be electrically connected to any unassociated hardware or to other bonds.

B. Connections between Windings

Any metallic connection between the primary and secondary windings of a distribution transformer (as in common neutral systems) shall be made externally and not within the transformer case.

(1) Vertical clearances between exposed energized parts of line switches and line disconnects (including fused and unfused line cutouts) and unprotected conductors of other circuits above and below shall not be less than the clearances specified by Table 2, Cases 8 to 13 .

Clearances between exposed parts of line switches and line disconnects (including fused or unfused line cutouts) which are energized from the same circuit, from exposed parts of different phases or polarities shall not be less than the clearances specified by Table 2, Case 17 .

(2) Lead wires shall be suitably insulated from cases of cutouts and switches at points of entrance thereto.

All unprotected lead wires including miscellaneous wiring shall clear braces, bolts and other line hardware a distance of not less than 1.5�.

Where necessary at points of entrance to cutouts and switches, lead wires of 0 - 5,000 volts may be less than 3 inches from the surface of crossarms ( Table 1, Case 9, Columns C, D and E ) but shall not be less than 1 inch from such surfaces.

(3) Switches and cutouts shall be so located that, when in either the open or closed position, all energized parts thereof are not less than 15 or 18 inches from the centerline of pole as required by Table 1, Case 8 , and no part of such equipment shall be in the climbing space except nonmetallic interphase shafts of gang operated switches and their associated unbonded hardware mounted at the top of the pole (see Figures 58�2 and 58�3 ). Such apparatus is permitted to be within the working space. The clearance of 15 or 18 inches need not apply to nonfusable pole�top switches provided the switches are installed substantially in the same vertical plane as the conductors to which they are attached, and no climbing space has to be provided through and above the level of such switches.

B. Enclosed Switches

All enclosed switches shall indicate clearly whether they are in the open or closed position.

(1) Grounded metal operating rods which pass through any supply or communication conductor level shall be protected with a suitable protective covering for a vertical distance of 8 feet above and below or 6 feet horizontally from such levels.

(2) Ungrounded metal operating rods which pass through only supply or communication conductor level shall:

a) Have a suitable insulating link or section installed at a point as near as possible to the switch; and

b) Have a suitable insulating link or section installed at a point between each conductor level through which it passes.

(3) All operating rods shall be securely held in position by a suitable means to afford clearances as specified in Table 2, Case 18 from conductors of circuits below the switch level.

(4) Where line switches are operated from the ground level by means of all�metal control mechanisms without suitable insulating links or sections, an insulated platform shall be provided unless such operating mechanism is effectively grounded.

A. Messenger and Span Wire Clearances

The suspension messenger or span wire of all traffic signals shall be installed to afford the clearances prescribed for span wires in Table 1, Column A , and Table 2, Column A .

B. Lead Wires

Lead wires of 0 - 750 volts to traffic signals supported on messengers may be less than the clearances above ground specified in Table 1, Column D, Cases 2 and 3 provided they are maintained at a clearance above ground as specified in Table 1, Column A, Cases 2 and 3 for the messenger on which they are supported.

C. Clearance above Thoroughfares

Traffic signals supported by span wires and supplied from circuits of 0 - 750 volts shall have a clearance of not less than 14 feet vertically above thoroughfares over which they are suspended (see Figure 58�4 ) except that where any thoroughfare is used by railroads, street railways, trolley coach lines and double deck motor coaches, clearance not less than the following shall be maintained:

Conveyance Using Thoroughfare

Minimum Clearance of Signalabove Thoroughfare

Street railways and coach lines operated by overhead trolley

Height of trolley conductor plus 1 foot (a)

Railroads which transport freight cars

25 Feet (b)

Double deck motor coaches

18 Feet

(b) May be reduced to 14 feet if signal is more than 8 1/2 feet from centerline of track.

Traffic signals supplied directly (without protective transformers) from circuits classified in excess of 750 volts shall be installed with clearances as prescribed for street lighting equipment.

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 ).

E. Lighting Units On Transformer or Switch Poles

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.

58.6 Time Switches, Meters, Metal Boxes, Other Apparatus and Associated Antennas

B. Ungrounded

Time switches, meters, metal boxes, other apparatus and associated antennas are not allowed in the climbing space.

C. Within 8 Feet of the Ground

Boxes or enclosures containing switches, meters, or other apparatus having accessible live parts, which are located 8 feet or less above the ground shall be effectively locked or sealed.

Metal boxes which contain supply or control equipment or conductors and are located 8 feet or less above the ground shall be effectively grounded.

Table 58�2 Ungrounded Cases from Line Conductors (a) (b)
Line Conductors		Comm.	0 - 750 Volts	750 - 7500 Volts	7500V - 22.5KV	22.5 kV & above
1	Vertical above Case	48 in.	3 in.(c)	12 in.(d)	18 in. (e)	24 in.
2	Vertical below Case	48 in.	10 in.(d)	12 in.(d)	18 in. (e)	24 in.
3	Horizontal from Case	N/A	6 in.	12 in.	18 in.	24 in.

Conveyance Using Thoroughfare	Minimum Clearance of Signalabove Thoroughfare
Street railways and coach lines operated by overhead trolley	Height of trolley conductor plus 1 foot (a)
Railroads which transport freight cars	25 Feet (b)
Double deck motor coaches	18 Feet