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(continued)
(Title 24, Part 3, Article 100.)
Grounding Connection (Ground Connection). (See Ground.)
(Title 24, Part 3, Article 100.)
Grounding Electrode (Ground Electrode). A conductor imbedded in the earth, used for maintaining ground potential on conductors connected to it, and for dissipating into the earth current conducted to it.
(Title 24, Part 3, Article 3-100.)
Grounding Conductor. A conductor used to connect equipment or the grounded circuit of a wiring system to a grounding electrode.
(Title 24, Part 3, Article 100.)
Grounding Electrode Resistance. The resistance of the grounding electrode to earth.
Grounding Transformer. A transformer intended primarily for providing a neutral point for system grounding purposes.
(Title 24, Part 3, Article 3-100.)
Group Operation. The essentially simultaneous operation of all poles of a multi-pole switching device by one operating mechanism.
(Title 24, Part 3, Article 3-100.)
Guarded. Covered, shielded, fenced, enclosed, or otherwise protected by means of suitable covers or casings, barriers, rails or screens, mats, or platforms intended to prevent or impede the approach of persons or objects to a point of danger.
(Title 24, Part 3, Article 3-100.)
High Voltage. A sustained voltage of more than 600 volts. (See Voltage.)
(Title 24, Part 3, Article 3-100.)
High-Voltage System. Associated electrical conductors and equipment operating at or intended to operate at a sustained voltage of more than 600 volts between conductors.
(Title 24, Part 3, Article 3-100.)
Hook Stick. (See Switch Stick.)
Hot Tools and Ropes. Tools and ropes which are especially designed for work on energized high voltage lines and equipment. Insulated aerial equipment especially designed for work on energized high voltage lines and equipment shall be considered hot line.
Indoor. Indoor, as an adjective, describes a device or equipment which, because of its construction, must be protected from the weather, or be installed in a location which is protected from the weather.
(Title 24, Part 3, Article 3-100.)
Induction Heating. The heating of a nominally conductive material due to its own I2 R losses when the material is placed in a varying electromagnetic held. R losses when the material is placed in a varying electromagnetic held.
Insulated. Separated from other conducting surfaces by a dielectric substance (including air space) offering a high resistance to the passage of current.
Note: When any object is said to be insulated, it is understood to be insulated in suitable manner for the conditions to which it is subjected. Otherwise, it is within the purpose of these orders, uninsulated. Insulating covering of conductors is one means of making the conductor insulated.
(Title 24, Part 3, Article 3-100.)
Insulation (As applied to Cable). That which is relied upon to insulate the conductor from other conductors or conducting parts or from ground.
(Title 24, Part 3, Article 3-100.)
Interlock. An electrical, mechanical, or key-locked device intended to prevent an undesired sequence of operations.
(Title 24, Part 3, Article 3-100.)
Interrupter Switch. (See Switching Devices.)
(Title 24, Part 3, Article 100.)
Interrupting Rating. (See Ratings.)
(Title 24, Part 3, Article 3-100.)
Isolated. Not readily accessible to persons unless special means of access are used.
Junction Box. (See Pull Box.)
(Title 24, Part 3, Article 3-100.)
Lanyard. A flexible line to secure a wearer of a safety belt or harness to a drop line, lifeline, or fixed anchorage.
Line Clearance Tree Trimming Operations. Operations which include the trimming, repairing, chemical treatment or removal of trees, brush and miscellaneous vegetation, performed in the vicinity of exposed energized overhead conductors and equipment.
Linemen's Body Belt. A leather or web (cotton or nylon) belt designed specifically for employees working on poles or structures. It consists of a waist belt, generally cushioned, with a front buckle, two D rings for attaching safety straps and a multiple-looped strap for holding rings, snaphooks, holsters and other tool holding devices.
Location. (See Environment.)
Magnetizing Current. (See Current -Excitation.)
Main Switch. (See Service Entrance Switch.)
(Title 24, Part 3, Article 3-100.)
Make and Latch (or Close and Hold) Rating. (See Ratings.)
(Title 24, Part 3, Article 3-100.)
Manhole. A chamber, in an underground system, containing working space large enough for a person o enter, which provides space and access for installation and maintenance of cables,transformers, or other equipment or apparatus.
(Title 24, Part 3, Article 3-100.)
Manhole Chimney. A vertical passageway for workers or equipment between the roof of the manhole and the surface (street) level.
(Title 24, Part 3, Article 3-100.)
Manual Control. (See Control.)
(Title 24, Part 3, Article 3-100.)
Manual Operation. (See Control.)
(Title 24, Part 3, Article 3-100.)
Maximum Voltage. (See Ratings.)
(Title 24, Part 3, Article 3-100.)
Metal-Clad Cable. A fabricated assembly of insulated conductor(s) in a flexible metallic enclosure.
(Title 24, Part 3, Article 3-100.)
Metal-Enclosed. Metal-enclosed, as an adjective, refers to electrical apparatus surrounded by a metal case or housing, usually grounded.
(Title 24, Part 3, Article 3-100.)
Minimum Bending Radius. The minimum recommended radius to which a conduit or an insulated cable may be bent, measured from its inner surface.
(Title 24, Part 3, Article 3-100.)
Minimum Operating Current. (See Current.)
Multiple Fuse. An assembly of two or more single-pole fuses.
Nominal System Voltage. (See Voltage.)
(Title 24, Part 3, Article 100.)
Nonpropagating Liquid. A liquid which, when subjected to a source of ignition, may burn but the flame will not spread from the source of ignition.
Oil (Filled) Cutout. (See Switching Devices.)
(Title 24, Part 3, Article 100.)
Open Wiring. Uninsulated conductors or insulated conductors without grounded metallic sheaths or shields installed above ground, but not inside apparatus or wiring enclosures.
(Title 24, Part 3, Article 3-100.)
Outdoor. Outdoor, as an adjective, describes a device or equipment of weatherproof construction, or a location exposed to the weather.
(Title 24, Part 3, Article 3-100.)
Overcurrent. (See Current.)
Overload. (See Current.)
Overtemperature Protective Device. (See Thermal Protector.)
(Title 24, Part 3, Article 3-100.)
Portable or Mobile Equipment. Electrical equipment mounted on skids, pads, legs, or vehicles, and capable of being moved to any required location.
Pothead. (See Cable Terminations.)
(Title 24, Part 3, Article 3-100.)
Power Fuse. (See Fuse.)
Protective Device. A device or combination of devices capable of detecting and automatically interrupting a specific condition.
(Title 24, Part 3, Article 3-100.)
Pull Box. A box with a blank cover into which workers may reach but not enter which is inserted in one or more runs of raceway to facilitate pulling, joining, supporting, or inspecting conductors. The term "pull box" includes but is not limited to: junction boxes, splice boxes, conductor support boxes, inspection boxes, and handholes.
(Title 24, Part 3, Article 3-100.)
Pulling Tension. The longitudinal force exerted on a cable during installation.
Qualified Electrical Worker. A qualified person who by reason of a minimum of two years of training and experience with high-voltage circuits and equipment and who has demonstrated by performance familiarity with the work to be performed and the hazards involved.
Qualified Line Clearance Tree Trimmer. A person who has completed a minimum of 18 months-related training and on-the-job experience and is familiar with the special techniques and hazards involved in line clearance tree trimming operations.
Qualified Line Clearance Tree Trimmer Trainee. Any worker regularly assigned to a line clearance tree trimming crew and undergoing on-the-job training who, in the course of such training, has demonstrated the ability to perform the assigned duties safely at that level of training.
Qualified Person. A person who by reason of experience or instruction is familiar with the operation to be performed and the hazards involved.
Raceway. Any channel for holding wires, cables or bus bars, which is designed expressly for, and used solely for, this purpose.
Note: Raceways shall be permitted to be of metal or insulating material and the term includes rigid metal conduit, rigid nonmetallic conduit, flexible metal conduit, electrical metallic tubing, underfloor raceways, cellular concrete floor raceways, cellular metal floor raceways, surface metal raceways, structural raceways, wireways and busways.
(Title 24, Part 3, Article 100.)
Rated. A designated value of an operating characteristic at which other characteristics are measured and specified.
(Title 24, Part 3, Article 3-100.)
Ratings.
(A) Basic Impulse Level (BIL). A reference impulse insulation strength expressed in terms of the crest value of the withstand voltage of a standard full impulse voltage wave.
(B) Interrupting Rating. Maximum interrupting capability under specified conditions, expressed in amperes or MVA.
(C) Make and Latch (Close and Hold) Rating. The highest RMS current at which the device or equipment is designed to operate.
(D) Short-Time Current Rating. The maximum RMS current a device, an assembly, or a bus is designed to carry for a specified short-time interval.
(Title 24, Part 3, Article 3-100.)
Readily Accessible. (See Accessible.)
(Title 24, Part 3, Article 100.)
Regulator Bypass Switch. (See Switching Devices.)
(Title 24, Part 3, Article 100.)
Release Free (Trip Free). A descriptive term indicating that the opening operation of a switching device can prevail over the closing operation during specified portions of the closing operation.
(Title 24, Part 3, Article 3-100.)
Riser (Cable Riser). A vertical run of insulate cable, associated raceway, and termination.
Safely Accessible. (See Accessible.)
Safety Strap. A web strap designed specifically for use in conjunction with a linemen's body belt to secure the employee to a pole or structure in a manner that permits work with both hands.
Service. The conductors and equipment for delivering energy from the electricity supply system to the wiring system of the premises served.
(Title 24, Part 3, Article 100.)
Service Conductors. That portion of the supply conductors which extends from the supply main, duct, or from transformers of the serving agency to the service equipment of the premises supplied. For overhead conductors this includes the conductors from the last line pole to the service equipment.
(Title 24, Part 3, Article 100.)
Service Entrance Conductors. The consumer-owned conductors extending between the service point and the service entrance equipment.
(Title 24, Part 3, Article 100.)
Service Entrance Switch (Main Switch). The disconnecting means and overcurrent protection installed at or near the service point.
(Title 24, Part 3, Article 100.)
Service Equipment. The necessary equipment, usually consisting of circuit breaker or switch and fuses, and their accessories, intended to constitute the main control and means of cutoff for the supply to a building or structure.
(Title 24, Part 3, Article 100.)
Service Factor. A multiplier which, applied to the rated output of an electric machine, indicates a permissible loading which may be carried continuously under the conditions for that service factor.
Service Point. The point of connection between the facilities of the serving agency and those of the consumer.
(Title 24, Part 3, Article 3-100.)
Shielded Cable. A cable in which the insulated conductor(s) is enclosed in a conducting envelope(s), so constructed that substantially every point on the surface of the insulation is at ground potential or at some predetermined potential with respect to ground.
Stored-Energy Operation. Operation by means of energy stored in the mechanism, sufficient to complete a specified operation.
Stress Cone. (See Cable Terminations.)
(Title 24, Part 3, Article 3-100.)
Submersible. Submersible, as an adjective, describes a device which is so constructed that it will operate satisfactorily when completely or partially submerged in a liquid under specified conditions.
Suitable. Capable of performing with safety the particular function specified in these Orders.
Supervised. Under continuous or intermittent surveillance by a local or remote operator or automatic data processing system.
Switch (Hook) Stick. A device with an insulated handle and a hook or other means for performing stick operation of a switching device.
Switching Device. A device designed to close and/or open an electric circuit.
(Title 24, Part 3, Article 100.)
Switching Devices.
(A) Circuit Breaker. A device designed to open and close a circuit by non-automatic means, and to open the circuit automatically on a predetermined overload of current, without injury to itself when properly applied within its rating.
(Title 24, Part 3, Article 100.)
(B) Cutout. An assembly of a fuse support with either a fuseholder, fuse carrier, or disconnecting blade. The fuseholder or fuse carrier may include a conducting element (fuse link), or may act as a disconnecting blade by the inclusion of a non-fusible member.
(Title 24, Part 3, Article 100.)
(C) Disconnecting Means. A device, or group of devices, or other means whereby the conductors of a circuit can be disconnected from their source of supply.
(Title 24, Part 3, Article 100.)
(D) Disconnecting (or Isolating) Switch (Disconnector, Isolator). A switch intended for isolating an electric circuit from the source of power. It has no interrupting rating and is intended to be operated only after the circuit has been opened by some other means.
(Title 24, Part 3, Article 3-100.)
(E) Interrupter Switch. A switch, capable of making, carrying, and interrupting specified currents.
(Title 24, Part 3, Article 100.)
(F) Oil Cutout (Oil-Filled Cutout). A cutout in which all or part of the fuse support and its fuse link or disconnecting blades are mounted in oil with complete immersion of the contacts and the fusible portion of the conducting element (fuse link), so that arc interruption by severing of the fuse link or by opening of the contacts will occur under oil.
(Title 24, Part 3, Article 100.)
(G) Oil Switch. A switch having contacts which operate under oil (or askarel or other suitable liquid).
(Title 24, Part 3, Article 100.)
(H) Regulator Bypass Switch. A specific device or combination of devices designed to bypass a regulator.
(Title 24, Part 3, Article 100.)
Tag. A system or method of identifying circuits, systems or equipment for the purpose of alerting persons that the circuit, system or equipment is being worked on.
Terminal Chamber. (See Cable Terminations.)
(Title 24, Part 3, Article 3-100.)
Test Position (of a switchgear assembly). That position in which the primary disconnecting devices of the removable element are separated by a safe distance from those in the housing and the secondary disconnecting devices are in operating contact.
(Title 24, Part 3, Article 3-100.)
Thermal Protector -General. An inherent protective device which is responsive to temperature or current, or both, and which, when properly applied, protects the equipment against overheating due to overload or failure to start.
(Title 24, Part 3, Article 3-100.)
Transformer Bank. A transformer installation consisting of two or more transformers.
Transformer Installation. An electrical installation consisting of one or more transformers, including associated lead wires and interconnections, which transforms electric energy from one or more alternating current circuits to one or more other alternating current circuits.
Transformer Primary Winding. The winding on the energy input (source) side.
Transformer Secondary Winding. The winding on the energy output (load) side.
Vault. A room (including manholes) of fire-resistant construction, primarily used to house electrical equipment.
(Title 24, Part 3, Article 3-100.)
Voltage.
(A) Maximum Voltage. (See Ratings.)
(Title 24, Part 3, Article 3-100.)
(B) Nominal System Voltage. A nominal value assigned to designate a system of a given voltage class.
(Title 24, Part 3, Article 3-100.)
(C) Voltage (of a circuit). The greatest root-mean-square (effective) difference of potential between any two conductors of the circuit concerned.
(Title 24, Part 3, Article 100.)
Note: On various systems such as 3-phase, 4-wire, single phase 3-wire and 3- wire direct current, there may be various circuits of various voltages.
(Title 24, Part 3, Article 100.)
(D) Voltage to Ground. In grounded circuits the voltage between the given conductor and that point or conductor of the circuit which is grounded; in ungrounded circuits, the greatest voltage between the given conductor and any other conductor of the circuit.
(Title 24, Part 3, Article 100.)
Weatherproof. So constructed or protected that exposure to the weather will not interfere with successful operation.
(Title 24, Part 3, Article 100.)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
(Formerly Article 51)
s 2703. Special Requirements.
Where these regulations contain special requirements for special classes of installations, or for installations under special conditions, such special requirements shall take precedence over the general requirements of the regulations in any point of apparent conflict or inconsistency.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 2704. Titles and Subtitles.
The titles and subtitles following each regulation number are intended to serve as a general guide and index to these regulations and are not necessarily to be considered as a part of any particular regulation.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 2705. Scope.
These High-Voltage Electrical Safety Orders are intended to establish essential requirements and minimum standards for the installation, operation, and maintenance of electrical installations and equipment to provide practical safety and such freedom from danger to personnel as the employment reasonably permits.
These orders are not to be regarded as a design specification or an instruction manual for untrained personnel.
(Title 24, Part 3, Section 90-1.)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2706. Application.
(a) These High-Voltage Electrical Safety Orders, apply to all electrical installations and electrical equipment operating or intended to operate on systems of more than 600 volts between conductors and to all work performed directly on or in proximity to such electrical installations, equipment or systems in all places of employment in the State of California as defined in Labor Code Section 6303. These orders do not apply to:
(1) Installations or conductors and equipment in ships, watercraft, railway rolling stock, or aircraft.
(2) Installations of conductors, equipment, and associated enclosures subject to the jurisdiction of the California Public Utilities Commission, that are owned, operated and maintained by an electric, communication or electric railway utility.
Exception: No. 1. These orders apply to conduit, vaults, and other like enclosures containing the conductors and equipment of such a utility when located indoors on premises not used exclusively for utility purposes, but do not apply to the utilities conductors and the equipment therein.
Exception: No. 2. Article 36, Work and Operating Procedures; and Article 38, Line Clearance Tree Trimming Operations apply to all work performed by electric utilities and electric railways.
(Title 24, Part 3, Sections 3-089-3 and 3-089-4.)
(b) After the date on which these orders become effective, all installations and equipment shall conform to these orders.
Exception: Existing installations and equipment which were in compliance with safety orders, or variances therefrom, in effect prior to the effective date of these safety orders, unless the hazard presented by the installation or equipment is, in the judgment of the Chief of the Division, of such severity as to warrant control by the application of the applicable sections of these orders.
(c) Regulations herein which may affect building standards apply to all buildings, or building alteration, or building modification for which construction is commenced after the effective date of the regulations. Date of commencement of construction for the purpose of this section, shall be:
(1) The advertising date for invitation of bids for State and local government projects:
(2) The building construction permit issuance date for other than government projects.
(Title 24, Part 3, Section 3-089-14.)
(d) For installation requirements not specifically contained herein, installations in compliance with Title 24, Part 3, in effect at the time of construction, will be considered as complying with the intent of these orders.
(e) Nothing contained in these regulations shall be considered as abrogating the provisions relating to public safety of any ordinance, rule or regulation of any governmental agency, providing such local ordinance, rule or regulation does not lessen the provisions for safety contained in these regulations.
(f) These orders take precedence over any other orders in the California Administrative Code, Title 8, relating to high-voltage facilities or work procedures that are inconsistent with them.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2707. Approvals.
Approved means acceptable to the Division of Occupational Safety and Health which has the responsibility and authority to grant the approval for the specified condition or application.
The Division of Occupational Safety and Health will approve materials, devices, appliances, installations, arrangement or methods of construction intended for use under these orders, provided necessary safety requirements are met for quality, strength, effectiveness, fire resistance, durability, and the protection of life and health.
(Title 24, Part 3, Section 110-2.)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2708. New Installations: Additions, Alterations, and Renewals of Existing Installations.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 2709. Variances from These Orders.
(a) Any employer may apply to the Division for a temporary order granting a variance from an occupational safety and health standard. Such temporary order shall be granted only if the employer files an application which meets the requirements of Sections 6450 through 6457, inclusive, of the California Labor Code.
(b) Any employer may apply to the Occupational Safety and Health Standards Board for a permanent variance from an occupational safety and health standard, order, special order, or portion thereof upon a showing of an alternative program, method, practice, means, device or process which will provide equal or superior safety for employees. Such application shall conform to the requirements of the California Administrative Code, Title 8, Chapter 3.5.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
(Formerly Article 52)
s 2710. Mounting Requirements.
Electrical apparatus and equipment shall be firmly secured to surfaces upon which it is mounted.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 2711. Readily and Safely Accessible.
Switches, circuit breakers, contactors, relays, and other control equipment requiring operation, examination, adjustment, maintenance, or repair shall be readily and safely accessible.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 2712. Atmospheric and Environmental Protection.
Electrical installations and equipment shall be constructed or protected to withstand the atmospheric and environmental conditions to which they will be subjected.
(Title 24, Part 3, Section 110-11.)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2713. Protection Against Physical Damage.
Electrical equipment installed in locations where it is exposed to physical damage shall be suitably protected.
(Title 24, Part 3, Section 110-17(b).)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 2714. Installation and Maintenance.
(a) All electrical installations shall be made in a workmanlike manner and shall be so designed, constructed, and installed that the hazard to personnel will be reduced, as far as it is reasonably possible. Installations of new equipment and conductors, and extensions, repairs, and changes in existing installations shall be made only by, or under the supervision or direction of, qualified electrical workers.
(Title 24, Part 3, Section 3-110-41.)
(b) All electrical installations shall be maintained in a safe operating condition. If any unsafe condition develops, it shall be promptly corrected.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2715. Identification.
All switches, circuit breakers, and other control devices shall be located or marked to indicate clearly the equipment controlled by them.
(Title 24, Part 3, Section 3-110-42.)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2716. Ampacities.
All conductors shall have ampacities to carry safely the normal load which they supply in accordance with the requirements of Section 2821.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 2717. Energized Parts.
Energized parts shall be so located or enclosed as to prevent accidental contact by persons or objects.
(Title 24, Part 3, Section 110-31.)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
(Formerly Article 53)
s 2719. Application.
This article applies to all equipment and wiring from the service point to and including the service equipment. (See Diagram 2719.)
(Title 24, Part 3, Section 3-230-200(e).)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18953(c), Health and Safety Code.
s 2720. General.
No building or premises shall be supplied at more than one service point except when one or more of the following conditions apply:
(a) Capacity Requirements. Where the load requirements of the installation are greater than the serving agency will supply through one set of service conductors, or where the capacity of available equipment is exceeded.
(b) Continuity of Service. Where the installation is of such a character as to require alternate or multiple sources of supply from the serving agency to ensure service continuity.
(c) Character of Load. Where the character of the load is of such a nature as to require isolation from other loads.
(d) Location of Load. Where the load is distributed so that more than one service point is desirable.
(Title 24, Part 3, Section 230-200.)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2721. Service Raceways.
Service conductors within buildings shall be installed in suitable raceways or be of approved meta-clad cable.
(Title 24, Part 3, Section 230-202.)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2722. Service Through Buildings.
Overhead or underground services or service entrance conductors shall not supply one building through another.
Exception: This requirement does not apply to conductors in conduit or duct placed under or encased in at least 3 inches of concrete or equivalent fire-resistant material.
(Title 24, Part 3, Section 3-230-202(i).)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2723. Service Entrance Conductors and Clearances.
Service entrance conductors to buildings or enclosures (including transformer vaults and enclosures, and substations, indoor and outdoor) shall be installed to conform to one of the following methods:
(Title 24, Part 3, Section 3-230-202.)
(a) Overhead service entrance conductors shall be permitted to be run open and unguarded, in which case they shall be supported and maintained at clearances not less than the minimum required by General Order No. 95, Rules for Overhead Electric Line Construction of the California Public Utilities Commission, 1981 Edition.
(Title 24, Part 3, Section 3-230-202(c).)
(b) Open service entrance conductors shall be attached to the building at one point only, and shall be suitably guarded against accidental contact. The length of open conductor between such point of attachment and the point where the conductors enter the building or the raceway shall be as short as practicable, but in no case greater than 3 feet. There shall be a conspicuous and permanent "HIGH VOLTAGE" sign placed on the outside immediately adjacent to the point of attachment.
(Title 24, Part 3, Sections 3-230-202(e) and 3-230-203.)
(c) Where service entrance conductors are installed in or on a building other than a substation or transformer vault or transformer enclosure, the conductors within and upon the building shall have an approved insulation and shall be installed in rigid conduit or in other approved raceways, or as metal-clad cable approved for the application.
(Title 24, Part 3, Section 3-230-202(j).)
(d) Suitably insulated service entrance conductors shall be permitted to be installed underground in conduit, raceway, pre-assembled flexible conduit, or shall be permitted to be direct buried at a depth of at least 36 inches. A grounded neutral conductor or an equipment grounding conductor, either bare or insulated, shall be permitted to be installed in the service entrance conduit or raceway or shall be permitted to be direct buried immediately adjacent to the associated service entrance conduit, raceway, or direct buried ungrounded conductors.
(Title 24, Part 3, Section 3-230-202(b).)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2724. Conductors in Service Entrance Raceway.
Conductors other than service entrance conductors and grounding conductors shall not be installed in service entrance raceways.
(Title 24, Part 3, Section 3-230-212.)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2725. Location of Switching Devices and Other Service Entrance Equipment.
(a) The service switching device(s) shall simultaneously disconnect all ungrounded conductors supplied through the service entrance conductors.
Exception: No. 1: Metering equipment shall be permitted to be placed on the source side of the service switching device and fuses, provided the metering is suitably enclosed and no energized parts or wiring are exposed or accessible to other than employees of the serving agency.
Exception: No. 2: Current transformers for protection of service equipment or current indication.
Exception: No. 3: When suitable overcurrent protection and disconnecting means are provided, a circuit used for an of the following purposes shall be permitted to also be connected on the source side of the service entrance switching device: (a) Fire pumps; and (b) Potential or control transformers for electrical operation or protection of the service equipment, or for voltage indication. If voltage indication is provided, it shall be on all phases.
(Title 24, Part 3, Section 3-230-205.)
(b) Surge and lightning protection equipment shall be connected to the source side of switching devices.
(Title 24, Part 3, Section 3-230-209.)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2726. Enclosure.
Energized parts of service entrance equipment, including instrument transformers, shall be enclosed so that they will not be exposed to accidental contact.
(Title 24, Part 3, Section 3-230-213.)
Note: Authority cited: Section 142.3, Labor ode. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2727. Ampacity.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 2728. Overcurrent Protection Requirements.
Service entrance conductors shall have a protective device in each ungrounded conductor, on the load side of, or as an integral part of the service entrance switch. The protective device shall be capable of detecting and interrupting all values of current in excess of its minimum trip setting or minimum melting point which can occur at its location. A fuse rated in continuous amperes not to exceed three times the nominal current rating of the conductors, or a circuit breaker with a minimum trip setting of not more than six times the nominal current rating of the conductors, will be considered as providing the required protection. The nominal current rating of the conductors shall be as required by Section 2821.
Exception: Where the serving agency agrees to provide overcurrent protection in accordance with the above requirement, no further overcurrent protection is required.
(Title 24, Part 3, Section 230-208.)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2729. Switching Requirements.
Each set of service entrance conductors shall have a service entrance switch meeting the requirements of Article 20 or 21.
The service entrance switch shall be group operated to open each set of ungrounded service entrance conductors and shall be capable of being padlocked in the open position.
(Title 24, Part 3, Section 3-230-74.)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2730. Switches in Parallel (Multiple).
When the load of an existing service entrance switch increases beyond its continuous current rating or continuity of service requires, a second service entrance switch of identical rating shall be permitted to be connected in parallel with it, provided:
(a) Each switch has interrupting capacity equal to or greater than the maximum fault current that can occur at its location.
(b) Each switch has its own overcurrent protection arranged to trip both switches automatically.
(c) Both switches have a common electrical or mechanical tripping arrangement.
Exception: Both switches need not have a common tripping arrangement if continuity of service requires that both switches not be tripped together, under fault conditions, and a suitable relay protection scheme is employed to separate faulted portions from the system.
(d) Both switches can be padlocked in the open position.
(Title 24, Part 3, Section 3-230-214.)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2731. Isolation Requirements.
A means conforming to Article 20 or 21 shall be provided to isolate the load and each overcurrent protective device in the service entrance conductors from all sources of supply.
(Title 24, Part 3, Section 3-230-215.)
Note: Authority cited: Section 142.3, Labor Code. Reference:Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2732. Paralleling and Isolating Switches.
(a) Two or more sets of service entrance conductors which can be operated in parallel shall be provided with a suitable means to isolate each set from all other sets of service entrance conductors.
(b) The paralleling switch or switches intended to make and break parallel shall conform to Article 20 or 21.
(c) Operation of paralleling switches shall be restricted to qualified and authorized persons only. A written switching procedure shall be made available to and followed by such personnel.
(Title 24, Part 3, Section 3-230-216.)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
(Formerly Article 54)
s 2734. Ampacity.
Feeder and branch circuit conductors shall meet the requirements of Section 2821.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 2735. Overcurrent Protection.
Feeders and branch circuits shall have a fault protective device in each ungrounded conductor. The protective device(s) shall be capable of detecting and interrupting all values of current in excess of their minimum trip setting or minimum melting point which can occur at their location. A fuse rated in continuous amperes not to exceed three times the nominal rating of the conductor or a breaker with relay having a minimum trip setting of not more than six times the nominal rating of the conductor will be considered as providing the required protection. The nominal rating of the cables will be as required by Section 2821.
Exception: Taps need not have separate fault protective devices, provided that the conductors are capable of withstanding the maximum short circuit current that can occur for the time necessary for a fault protective device on the source side of the conductors to operate.
(Title 24, Part 3, Section 3-240-100 and 3-240-101.)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2736. Switching Requirements.
A switch meeting the requirements of these regulations shall be installed on the source end of each feeder or branch circuit.
(a) Paralleling Switches.
(1) Two or more feeders which can be operated in a parallel shall be provided with a suitable switch(es) to isolate each feeder from all other feeders.
(2) The switch(es) intended to make and break parallel shall conform to Article 20 or 21.
(3) Operation of paralleling switches shall be restricted to qualified and authorized persons only. A written switching procedure shall be made available to and followed by such personnel.
(Title 24, Part 3, Section 3-710-24(r).)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2737. Isolation Requirements.
Each feeder shall be arranged so that it can be isolated from all sources of supply except that isolating switches are not required for taps. Isolating switches shall meet the requirements of Articles 20 or 21.
(Title 24, Part 3, Section 3-710-24(r).)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
(Formerly Article 55)
s 2739. Grounding of Systems and Circuits -General.
(a) Grounding of high-voltage systems and circuits is permitted, but is not mandatory unless specifically required elsewhere in these regulations. Where high-voltage systems are grounded, the applicable requirements of this Article 6 shall apply.
(b) If the system is to be grounded, a grounding connection shall be made to the system neutral if available. This connection shall be made at or on the source side of the service entrance equipment.
(c) Grounding connections shall be arranged to prevent objectionable current in the equipment grounding conductor during normal system operation. The temporary current carried by the equipment grounding conductor during fault conditions, while the grounding system is performing its intended protective function, is not objectionable.
(d) Grounding equipment and connections shall have ample thermal capacity to carry safely any current which may be imposed on them by the system.
(e) Grounding connections shall be clamp type, pressure type, welded, or other approved type.
(f) Grounding electrodes shall be of corrosion-resistant material and of adequate size, number, and location to effectively ground the system.
(g) Local piping systems, well casings, building frames, and the like shall not be used as system grounding electrodes unless their resistance to ground will be maintained low enough to insure effective grounding.
(Title 24, Part 3, Section 3-250-150(a)-(g).)
(h) A system neutral derived from an adequately rated grounding transformer shall be permitted to be used for grounding a high-voltage system.
(Title 24, Part 3, Section 3-250-151.)
(i) High-voltage systems supplying portable high-voltage equipment covered by Section 2743 shall be grounded.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2740. Solidly Grounded Neutral Systems.
(a) Grounding of solidly grounded neutral systems shall be accomplished in a manner illustrated by Diagram 2740 if the system neutral is available at the service entrance equipment.
(b) If the grounded neutral conductor is carried into the premises, it shall be identified as the grounded conductor. The minimum insulation level for neutral conductors of solidly grounded systems shall be 600 volts.
Exception: Bare conductors be used for the neutral of direct buried portions of solidly grounded systems.
(c) The neutral grounding conductor shall be permitted to be a bare conductor if properly isolated from phase conductors and protected from physical damage.
(d) Equipment grounding circuit conductors shall be permitted to be bare and shall be connected to the ground bus and grounding electrode conductor at the service entrance equipment. (See Diagram 2740.)
(e) Multiple grounding of the equipment grounding conductor is permitted.
(f) The use of multiple neutral grounds on exterior wiring systems is permitted.
(Title 24, Part 3, Section 250-152.)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2741. Impedance Grounded Neutral Systems.
(a) Grounding of impedance grounded neutral systems shall be accomplished in a manner illustrated by Diagram 2741, if practicable.
(b) If the impedance grounded neutral conductor is carried into the premises, it shall be identified, as well as fully insulated with the same insulation as the phase conductors.
(c) The system neutral shall not be connected to ground except through the neutral grounding impedance.
(d) Equipment grounding conductors shall be permitted to be bare and shall be connected to the ground bus and grounding electrode conductor at the service entrance equipment. (See Diagram 2741.)
(Title 24, Part 3, Section 250-153.)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2742. Grounding of Equipment.
(a) The following shall be permanently and effectively grounded before the associated high-voltage equipment is energized.
(1) Metal conduit, cable armor, and other metal raceways or enclosures for wire and cable.
(2) Lightning arrester ground terminals and such other equipment.
(3) Non-energized metal parts of all fixed equipment and associated fences, housings, enclosures, and supporting structures.
(b) Effective grounding of all equipment shall be assured by the use of an equipment grounding conductor, where feasible, such that the path to ground will:
(1) Be permanent and continuous.
(2) Have ample ampacity to conduct safely any currents liable to be imposed upon it.
(3) Have impedance sufficiently low to limit the potential above ground, and to facilitate the operation of the overcurrent or ground fault detecting devices in the system. Where the conduit is intended to function as the equipment grounding conductor, approved threaded couplings, hubs, and joints, or double locknuts and bushings with bonding jumpers are required.
(c) Unless grounding conductors are an integral part of the cable, they shall be no smaller than No. 6 AWG for mechanical strength. Grounding conductors shall be of corrosion-resistant approved material, or shall be suitably protected against corrosion, and shall have thermal capacity for the conditions imposed on them by the system.
(d) Grounding connections shall be clamp type, pressure type, welded, or other approved types. Solder-type connections shall not be used for grounding.
(e) Grounding electrodes shall be of corrosion-resistant material, and the size number, and the location shall be adequate to provide effective grounding of the equipment.
(f) Local piping systems, well casings, building frames, and the like shall not be used as grounding electrodes unless their resistance to ground will be maintained low enough to insure effective grounding.
(g) Noncurrent-carrying metal parts of all portable equipment shall be grounded.
(h) Specific Exceptions.
(1) Grounding of equipment mounted on poles shall comply with Rules 58.3-C and 58.4-C, General Order No. 95, 1981 Edition Rules for Overhead Electric Line Construction of the California Public Utilities Commission, which are hereby incorporated by reference.
(2) Where high-voltage equipment and associated metal enclosures or structures are intentionally isolated from ground, provision shall be made to prevent any person who can make contact with ground from contacting the isolated equipment and associated metal enclosures or structures when such equipment is energized. Intentional grounds shall be applied after such equipment is de-energized and before access is permitted, in accordance with Work Procedures, Article 36.
(Title 24, Part 3, Section 250-155.)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code; and Section 18943(c), Health and Safety Code.
s 2743. Grounding of Systems Supplying Portable High-Voltage Equipment.
(a) Portable high-voltage equipment shall be supplied from a system having its neutral grounded through an impedance.
Where a delta-connected high-voltage system is used to supply portable equipment, a system neutral shall be derived.
(b) Exposed non-energized metal parts of portable equipment shall be connected by a continuous ground return conductor to the point at which the system neutral impedance is connected to earth.
(c) The product of the maximum ground fault current and the impedance of the ground return conductor shall be such as to limit the voltage developed between the portable equipment frame and ground (by the flow of ground fault current) to not more than 100 volts.
(d) Ground fault detection and relaying shall be provided to automatically de-energize any high-voltage system component which has developed a ground fault. The continuity of the equipment ground return conductor shall be continuously monitored so as to de-energize automatically the high-voltage feeder to the portable equipment upon loss of continuity of the ground return conductor.
(e) The grounding electrode to which the portable equipment system neutral impedance is connected shall be isolated from and separated in the ground by at least 20 feet from any other system or equipment grounding electrode, and there shall be no direct connection between the grounding electrodes, such as buried pipe, fence, etc.
(f) High-voltage trailing cables and couplers for interconnection of portable equipment shall be the type approved for the purpose. See Article 14.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
(Formerly Article 56)
s 2745. CoversRequired. (continued)