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Subchapter 5. Electrical Safety Orders
Group 1. Low-Voltage Electrical Safety Orders
Article 1. Definitions

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§2300. Scope.

(a) Only definitions of terms peculiar to and essential to the proper use of this Safety Order are included. In general, only those terms used in two or more Articles are defined in Article 1. Other definitions are included in the Article in which they are used but may be referenced in Article 1.
(b) Definitions.
Acceptable. An installation or equipment is acceptable to the Division of Occupational Safety and Health, if approved as prescribed in Section 2305.4 of these Safety Orders.
Accepted. An installation is “accepted” if it has been inspected and found by a nationally recognized testing laboratory to conform to specified plans or to procedures of applicable codes.
(A) Equipment Application (Other than Wiring Methods). Admitting close approach because not guarded by locked doors, elevation, or other effective means.
(B) Readily. Capable of being reached quickly for operation, renewal, or inspections, without requiring those to whom ready access is requisite to climb over or remove obstacles or to resort to portable ladders, chairs, etc.
(C) Safely. Not exposing persons installing, operating, maintaining, or inspecting electrical apparatus to serious risks of tripping or falling or of coming in contact with energized electrical parts, moving machinery, surfaces or objects operating at high temperatures or other hazardous equipment.
(D) Wiring Method Application. Capable of being removed or exposed without damaging the building structure or finish, or not permanently closed in by the structure or finish of the building (see “Concealed” and “Exposed”).
Ampacity. The current, in amperes, that a conductor can carry continuously under the conditions of use without exceeding its temperature rating.
Appliance. Utilization equipment, generally other than industrial, normally built in standardized sizes or types, which is installed or connected as a unit to perform one or more functions such as clothes washing, air conditioning, food mixing, deep frying, etc.
Appliance, Fixed. An appliance which is fastened or otherwise secured at a specific location.
Appliance, Portable. An appliance which is actually moved or can easily be moved from one place to another in normal use.
Approved. The conductors and equipment required or permitted by these orders shall be acceptable to the Division of Occupational Safety and Health only if approved as prescribed in Section 2305.4 of these Safety Orders.
Armored Cable (Type AC). A fabricated assembly of insulated conductors in a flexible metallic enclosure.
Askarel. A generic term for a group of nonflammable synthetic chlorinated hydrocarbons used as electrical insulating media. Askarels of various compositional types are used. Under arcing conditions the gases produced, while consisting predominantly of noncombustible hydrogen chloride, can include varying amounts of combustible gases depending upon the askarel type.
Attachment Plug (Plug Cap) (Cap). A device which, by insertion in a receptacle, establishes connection between the conductors of the attached flexible cord and the conductors connected permanently to the receptacle.
Authorized Person. A qualified person delegated to perform specific duties under the conditions existing.
Automatic. Self-acting, operating by its own mechanism when actuated by some impersonal influence, as, for example, a change in current strength, pressure, temperature, or mechanical configuration.
Bare Conductor. See Conductor.
Barricade. Physical obstruction such as tapes, screens, cones, or structures that are setup in a manner intended to warn and limit access to a hazardous area.
Barrier. A physical obstruction that is intended to prevent contact with equipment or live parts or to prevent unauthorized access to a work area.
Bathroom. An area including a basin with one or more of the following: a toilet, a tub, or a shower.
Bond. An electrical connection from one metallic element to another for the purpose of minimizing potential differences and providing suitable conductivity for fault current or for mitigation of leakage current and electrolytic action.
Bonding (Bonded). The permanent joining of metallic parts to form an electrically conductive path which will assure electrical continuity and the capacity to conduct safely any current likely to be imposed.
Bonding Jumper. A reliable conductor to assure the required electrical conductivity between metal parts required to be electrically connected.
Bonding Jumper, Circuit. The connection between portions of a conductor in a circuit to maintain required ampacity of the circuit.
Bonding Jumper, Equipment. The connection between two or more portions of the equipment grounding conductor.
Bonding Jumper, Main. The connection between the grounded circuit conductor and the equipment grounding conductor at the service.
Branch Circuit. The circuit conductors between the final overcurrent device protecting the circuit and the outlet(s).
Branch Circuit, Appliance. A branch circuit supplying energy to one or more outlets to which appliances are to be connected; such circuits to have no permanently connected lighting fixtures not a part of an appliance.
Branch Circuit, General Purpose. A branch circuit that supplies a number of outlets for lighting and appliances.
Branch Circuit, Individual. A branch circuit that supplies only one utilization equipment.
Branch Circuit, Multiwire. A branch circuit consisting of two or more ungrounded conductors having a potential difference between them, and an identified grounded conductor having equal potential difference between it and each ungrounded conductor of the circuit and which is connected to the neutral conductor of the system.
Building. A structure which stands alone or which is cut off from adjoining structures by fire walls with all openings therein protected by approved fire doors.
Building Space. A room, vault, or wiring enclosures such as conduit, pull box, switchboards, and other like enclosures.
Cabinet. An enclosure designed either for surface or flush mounting and provided with a frame, mat, or trim in which a swinging door or doors are or can be hung.
Cable Sheath. A protective covering applied to cables.
Cable Tray System. A unit or assembly of units or sections and associated fittings forming a rigid structural system used to securely fasten or support cables and raceways. Cable tray systems include ladders, troughs, channels, solid bottom trays, and other similar structures.
Cablebus. An assembly of insulated conductors with fittings and conductor terminations in a completely enclosed, ventilated, protective metal housing.
Cell Line. An assembly of electrically interconnected electrolytic cells supplied by a source of direct current power.
Cell Line Attachments and Auxiliary Equipment. Cell line attachments and auxiliary equipment include, but are not limited to, auxiliary tanks, process piping, ductwork, structural supports, exposed cell line conductors, conduits and other raceways, pumps, positioning equipment, and cell cutout or bypass electrical devices. Auxiliary equipment also includes tools, welding machines, crucibles, and other portable equipment used for operation and maintenance within the electrolytic cell line working zone. In the cell line working zone, auxiliary equipment includes the exposed conductive surfaces of ungrounded cranes and crane-mounted cell-servicing equipment.
Center Pivot Irrigation Machine. A multi-motored irrigation machine that revolves around a central pivot and employs alignment switches or similar devices to control individual motors.
Certified. Equipment is “certified” if it bears a label, tag, or other record of certification that the equipment:
(A) Has been tested and found by a nationally recognized testing laboratory to meet nationally recognized standards or to be safe for use in a specified manner; or
(B) Is of a kind whose production is periodically inspected by a nationally recognized testing laboratory and is accepted by the laboratory as safe for its intended use.
Circuit. A conductor or system of conductors through which an electric current is intended to flow.
Circuit Breaker. A device designed to open and close a circuit by nonautomatic means and to open the circuit automatically on a predetermined overcurrent without damage to itself when properly applied within its rating.
(A) Adjustable. (As applied to Circuit Breakers.) A qualifying term indicating that the circuit breaker can be set to trip at various values of current and/or time within a predetermined range.
(B) Instantaneous Trip. (As applied to Circuit Breakers.) A qualifying term indicating that no delay is purposely introduced in the tripping action of the circuit breaker.
(C) Inverse Time. (As applied to Circuit Breakers.) A qualifying term indicating there is purposely introduced a delay in the tripping action of the circuit breaker, which delay decreases as the magnitude of the current increases.
(D) Nonadjustable. (As applied to Circuit Breakers.) A qualifying term indicating that the circuit breaker does not have any adjustment to alter the value of current at which it will trip or the time required for its operation.
(E) Setting. (Of Circuit Breaker.) The value of current and/or time at which an adjustable circuit breaker is set to trip.
Concealed. Rendered inaccessible by the structure or finish of the building. Wires in concealed raceways are considered concealed, even though they may become accessible by withdrawing them. [See “Accessible -(As applied to wiring methods)”]
(A) Bare. A conductor having no covering or electrical insulation whatsoever. (See “Conductor, Covered.”)
(B) Covered. A conductor encased within material of composition or thickness that is not recognized by these Orders as electrical insulation. (See “Conductor, Bare.”)
Current-Carrying Part. A conductor connected in an electric circuit to a source of voltage.
(C) Insulated. A conductor encased within material of composition and thickness that is recognized by these Orders as electrical insulation.
Conduit. (See “Raceway.”)
Conduit Body. A separate portion of a conduit or tubing system that provides access through one or more removable covers to the interior of the system at a junction of two or more sections of the system or at a terminal point of the system. Boxes such as FS and FD or larger cast or sheet metal boxes are not classified as conduit bodies.
Connector, Pressure (Solderless). A device that establishes a connection between two or more conductors or between one or more conductors and a terminal by means of mechanical pressure and without the use of solder.
Continuous Duty. (See under “Duty.”)
Continuous Load. A load where the maximum current is expected to continue for three hours or more.
Controller. A device or group of devices that serves to govern, in some predetermined manner, the electric power delivered to the apparatus to which it is connected.
Cooking Unit, Counter-Mounted. A cooking appliance designed for mounting in or on a counter and consisting of one or more heating elements, internal wiring, and built-in or separately mountable controls. (See “Oven, Wall-Mounted.”)
Covered Conductor. (See under “Conductor.”)
Current-Carrying Part. A conductor connected in an electric circuit to a source of voltage.
Cutout Box. An enclosure designed for surface mounting and having swinging doors or covers secured directly to and telescoping with the walls of the box proper. (See “Cabinet.”)
Damp Location. (See under “Location.”)
Dead Front Without live parts exposed to a person on the operating side of the equipment.
Deenergized. Free from any electrical connection to a source of potential difference and from electrical charge; not having a potential different from that of the earth.
Demand Factor. The ratio of the maximum demand of a system, or part of a system, to the total connected load of a system or the part of the system under consideration.
Device. A unit of an electrical system which is intended to carry but not utilize electric energy.
Dielectric Heating. The heating of a nominally insulating material due to its own dielectric losses when the material is placed in a varying electric field.
Different Systems. Those which derive their supply from different sources, or from individual transformers or banks of transformers which do not have their secondary windings interconnected, or from individual service switches.
Disconnecting Means. A device, or group of devices, or other means by which the conductors of a circuit can be disconnected from their source of supply.
Division. Unless otherwise designated in this subchapter, the term “Division” refers to the current Division of Occupational Safety and Health or any of its predecessors including the former Division of Industrial Safety or the Division of Occupational Safety and Health Administration. Reference to the former Division of Industrial Safety or Division of Occupational Safety and Health Administration in these orders is meant to refer to their successor, the Division of Occupational Safety and Health, or any subsequent successor agency.
Dry Location. (See under “Location.”)
Dustproof. So constructed or protected that dust will not interfere with its successful operation.
Dust-Tight. So constructed that dust will not enter the enclosing case.
(A) Continuous Duty. Operation at a substantially constant load for an indefinitely long time.
(B) Intermittent Duty. Operation for alternate intervals of (1) load and no load; or (2) load and rest; or (3) load, no load and rest.
(C) Periodic Duty. Intermittent operation in which the load conditions are regularly recurrent.
(D) Short Time Duty. Operation at a substantially constant load for a short and definitely specified time.
(E) Varying Duty. Operation at loads, and for intervals of time, both of which may be subject to wide variation.
Electrolytic Cell Line Working Zone. The cell line working zone is the space envelope wherein operation or maintenance is normally performed on or in the vicinity of exposed energized surfaces of electrolytic cell lines or their attachments.
Electrolytic Cells. A tank or vat in which electrochemical reactions are caused by applying energy for the purpose of refining or producing usable materials.
Enclosed. Surrounded by a case, housing, fence or walls which will prevent persons from accidentally contacting energized parts.
Enclosure. The case or housing of apparatus, or the fence or wall surrounding an installation to prevent personnel from accidentally contacting energized parts, or to protect the equipment from physical damage.
Energized. Electrically connected to a source of potential difference.
Energized Parts (Live Parts). Parts which are of a potential different from that of the earth, or some conducting body which serves in place of the earth.
Fall Protection. Any equipment, device, or system that prevents an employee from falling from an elevated location or mitigates the effect of such a fall.
Equipment. A general term including material, fittings, devices, appliances, fixtures, apparatus, and the like used as a part of, or in connection with, an electrical installation.
Equipment Grounding Conductor. See “Grounding Conductor, Equipment.”
Explosion-Proof Apparatus. Apparatus enclosed in a case that is capable of withstanding an explosion of a specified gas or vapor which may occur within it and of preventing the ignition of a specified gas or vapor surrounding the enclosure by sparks, flashes, or explosion of the gas or vapor within, and which operates at such an external temperature that a surrounding flammable atmosphere will not be ignited thereby.
Exposed. (As applied to live parts.) Capable of being inadvertently touched or approached nearer than a safe distance by a person. It is applied to parts not suitably guarded, isolated, or insulated. (See “Accessible” and “Concealed.”)
Exposed. (As applied to wiring methods.) On or attached to the surface or behind panels designed to allow access. [See “Accessible -(As applied to wiring methods)”]
Exposed. (For the purposes of Article 87.) Where the circuit is in such a position that in case of failure of supports or insulation, contact with another circuit may result.
Externally Operable. Capable of being operated without exposing the operator to contact with live parts.
Fall Protection. Any equipment, device, or system that prevents an employee from falling from an elevated location or mitigates the effect of such a fall.
Feeder. All circuit conductors between the service equipment, the source of a separate derived system, or other power supply source and the final branch circuit overcurrent device.
Fitting. An accessory such as a locknut, bushing, or other part of a wiring system that is intended primarily to perform a mechanical rather than an electrical function.
Fountain. Fountains, ornamental pools, display pools, and reflection pools.
NOTE: This definition does not include drinking fountains.
Ground. A conducting connection, whether intentional or accidental, between an electrical circuit or equipment and the earth, or to some conducting body that serves in place of the earth.
Grounded. Connected to earth or to some conducting body that serves in place of the earth.
Grounded, Effectively. Intentionally connected to earth through a ground connection or connections of sufficiently low impedance and having sufficient current-carrying capacity to prevent the buildup of voltages that may result in undue hazards to connected equipment or to persons.
Grounded Conductor. A system or circuit conductor that is intentionally grounded.
Grounding Conductor. A conductor used to connect equipment or the grounded circuit of a wiring system to a grounding electrode or electrodes.
Grounding Conductor, Equipment. The conductor used to connect the noncurrent-carrying metal parts of equipment, raceways, and other enclosures to the system grounded conductor, the grounding electrode conductor, or both, at the service equipment or at the source of a separately derived system.
Grounding Electrode Conductor. The conductor used to connect the grounding electrode to the equipment grounding conductor, to the grounded conductor, or to both, of the circuits at the service equipment or at the source of a separately derived system.
Ground-Fault Circuit-Interrupter. A device intended for the protection of personnel that functions to de-energize a circuit or portion thereof within an established period of time when a current to ground exceeds some predetermined value that is less than that required to operate the overcurrent protective device of the supply circuit.
Guarded. Covered, shielded, fenced, enclosed, or otherwise protected by means of suitable covers, casings, barriers, rails, screens, mats, or platforms to remove the likelihood of approach to a point of danger or contact by persons or objects.
Healthcare Facilities. Buildings or portions of buildings in which medical, dental, psychiatric, nursing, obstetrical, or surgical care are provided.
NOTE: Healthcare facilities include, but are not limited to, hospitals, nursing homes, limited care facilities, clinics, medical and dental offices, and ambulatory care centers, whether permanent or movable.
Heating Equipment. For the purposes of Article 77.2, the term “heating equipment” includes any equipment used for heating purposes if heat is generated by induction or dielectric methods.
Hoistway. Any shaftway, hatchway, well hole, or other vertical opening or space that is designed for the operation of an elevator or dumbwaiter.
Identified (as applied to equipment). Approved as suitable for the specific purpose, function, use, environment, or application, where described in a particular requirement.
NOTE: Some examples of ways to determine suitability of equipment for a specific purpose, environment, or application include investigations by a nationally recognized testing laboratory (through listing and labeling), inspection agency, or other organization recognized under the definition of “acceptable.”
Induction Heating. The heating of a nominally conductive material due to its own I2R losses when the material is placed in a varying electromagnetic field.
Insulated. Separated from other conducting surfaces by a dielectric (including air space) offering a high resistance to the passage of current.
Insulated Conductor. See “Conductor, Insulated.”
Interlock. An electrical, mechanical, or key-locked device intended to prevent an undesired sequence of operations.
Interrupting Rating. The highest current at rated voltage that an overcurrent protective device is intended to interrupt under standard test conditions.
Irrigation Machine. An electrically driven or controlled machine, with one or more motors, not hand portable, and used primarily to transport and distribute water for agricultural purposes.
Isolated. (As applied to location.) Not readily accessible to persons unless special means for access are used.
Isolated Power System. A system comprising an isolating transformer or its equivalent, a line isolation monitor, and its ungrounded circuit conductors.
Labeled. Equipment is “labeled” if there is attached to it a label, symbol, or other identifying mark of a nationally recognized testing laboratory, that maintains periodic inspection of production of such equipment and by whose labeling is indicated compliance with nationally recognized standards or tests to determine safe usage in a specified manner.
Lighting Outlet. An outlet intended for the direct connection of a lampholder, a lighting fixture, or a pendant cord terminating in a lampholder.
Listed. Equipment or materials included in a list published by a nationally recognized testing laboratory that maintains periodic inspection of production of such equipment, and whose listing states either that the equipment meets nationally recognized standards or has been tested and found safe for use in a specified manner.
Live Parts. Energized conductive components.
(A) Damp Location. Partially protected locations under canopies, marquees, roofed open porches, and like locations, and interior locations subject to moderate degrees of moisture, such as some basements, some barns, and some cold storage warehouses.
(B) Dry Location. A location not normally subject to dampness or wetness. A location classified as dry may be temporarily subject to dampness or wetness, as in the case of a building under construction.
(C) Wet Location. Installations underground or in concrete slabs or masonry in direct contact with the earth, and locations subject to saturation with water or other liquids, such as vehicle washing areas, and locations exposed to weather and unprotected.
Locking in the Open Position. The use of lockable devices, such as padlocks, combination locks or other positive methods or procedures which will effectively prevent unexpected or inadvertent energizing of a designated circuit, equipment or appliance.
Metal-Clad Cable (Type MC). A factory assembly of one or more insulated circuit conductors with or without optical fiber members enclosed in an armor of interlocking metal tape, or a smooth or corrugated metallic sheath.
Metal-Enclosed. Metal-enclosed, as an adjective, refers to electrical apparatus surrounded by a metal case or housing.
Mineral-Insulated Metal-Sheathed Cable (Type MI). Type MI, mineral-insulated metal-sheathed, cable is a factory assembly of one or more conductors insulated with a highly compressed refractory mineral insulation and enclosed in a liquidtight and gastight continuous copper or alloy steel sheath.
Minimum Approach Distance. The closest distance a qualified person, which includes qualified electrical worker, qualified tree worker, and qualified line clearance tree trimmer may approach an exposed energized object.
Mobile X-Ray. X-ray equipment mounted on a permanent base with wheels or casters or both for moving while completely assembled.
Motor Control Center. An assembly of one or more enclosed sections having a common power bus and principally containing motor control units.
Nonmetallic-Sheathed Cable (Types NM, NMC, and NMS). A factory assembly of two or more insulated conductors having an outer sheath of moisture resistant, flame-retardant, nonmetallic material.
Open Wiring. Uninsulated conductors or insulated conductors without grounded metallic sheaths or shields installed above ground, but not inside apparatus or wiring enclosures.
Open Wiring on Insulators. Open wiring on insulators is an exposed wiring method using cleats, knobs, tubes, and flexible tubing for the protection and support of single insulated conductors run in or on buildings, and not concealed by the building structure.
Outlet. A point on the wiring system at which current is taken to supply utilization equipment.
Outline Lighting. An arrangement of incandescent lamps or electric discharge lighting to outline or call attention to certain features such as the shape of a building or the decoration of a window.
Oven, Wall-Mounted. An oven for cooking purposes designed for mounting in or on a wall or other surface and consisting of one or more heating elements, internal wiring, and built-in or separately mountable controls. (See “Cooking Unit, Counter-Mounted.”)
Overcurrent. Any current in excess of the rated current of equipment or the ampacity of a conductor. It may result from overload, short circuit, or ground fault.
Overload. Operation of equipment in excess of normal, full-load rating, or of a conductor in excess of rated ampacity that, when it persists for a sufficient length of time, would cause damage or dangerous overheating. A fault, such as a short circuit or ground fault, is not an overload. (See Overcurrent.)
Panelboard. A single panel or group of panel units designed for assembly in the form of a single panel including buses, automatic overcurrent devices, and with or without switches for the control of light, heat, or power circuits; designed to be placed in a cabinet or cutout box placed in or against a wall or partition and accessible only from the front. (See “Switchboard.”)
Permanently Installed Decorative Fountains and Reflection Pools. Pools that are constructed in the ground, on the ground, or in a building in such a manner that the fountain or pool cannot be readily disassembled for storage, whether or not served by electrical circuits of any nature. These units are primarily constructed for their aesthetic value and are not intended for swimming or wading.
Permanently Installed Swimming, Wading, and Therapeutic Pools. Pools that are constructed in the ground or partially in the ground, and all other capable of holding water in a depth greater than 42 in. (1.07 m). The definition also applies to all pools installed inside of a building, regardless of water depth, whether or not served by electric circuits of any nature.
Portable X-Ray. X-ray equipment designed to be hand-carried.
Power and Control Tray Cable (Type TC). A factory assembly of two or more insulated conductors, with or without associated bare or covered grounding conductors under a nonmetallic sheath, approved for installation in cable trays, in raceways, or where supported by a messenger wire.
Power-Limited Tray Cable (Type PLTC). A factory assembly of two or more insulated conductors under a nonmetallic jacket.
Power Outlet. An enclosed assembly which may include receptacles, circuit breakers, fuseholders, fused switches, buses and watt-hour meter mounting means; intended to supply and control power to mobile homes, recreational vehicles or boats, or to serve as a means for distributing power required to operate mobile or temporarily installed equipment.
Premises Wiring (Premises Wiring System). That interior and exterior wiring, including power, lighting, control, and signal circuit wiring together with all of its associated hardware, fittings, and wiring devices; both permanently and temporarily installed which extends from the service point of utility conductors or source of power (such as a battery, a solar photovoltaic system, or a generator, transformer, or converter) to the outlet(s). Such wiring does not include wiring internal to appliances, fixtures, motors, controllers, motor control centers, and similar equipment.
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, distributing or inspecting conductors. The term “pull box” includes but is not limited to: junction boxes, splice boxes, conductor support boxes, inspection boxes, and handholes.
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 Person. A person, designated by the employer, who has received training in and has demonstrated skills and knowledge in the construction and operation of electric equipment and installations and the hazards involved.
1. Whether an employee is considered to be a “qualified person” will depend upon various circumstances in the workplace. For example, it is possible for an individual to be considered “qualified” with regard to certain equipment in the workplace, but “unqualified” as to other equipment.
2. An employee who is undergoing on-the-job training and who, in the course of such training, has demonstrated an ability to perform duties safely at his or her level of training and who is under the direct supervision of a qualified person is considered to be a qualified person for the performance of those duties.
Qualified Tree Worker. An employee who, through related training and on-the-job experience, has demonstrated familiarity with the techniques and hazards of tree maintenance, removal, and the equipment used in the specific operations involved.
Raceway. An enclosed channel of metal or nonmetallic materials designed expressly for holding wires, cables, or busbars, with additional functions as permitted in these orders. Raceways include, but are not limited to rigid metal conduit, rigid nonmetallic conduit, intermediate metal conduit, liquid-tight flexible conduit, flexible metallic tubing, flexible metal conduit, electrical nonmetallic tubing, electrical metallic tubing, underfloor raceways, cellular concrete floor raceways, cellular metal floor raceways, surface raceways, wireways, and busways.
Rainproof. So constructed, protected, or treated as to prevent rain from interfering with successful operation of the apparatus.
Raintight. So constructed or protected that exposure to a beating rain will not result in the entrance of water.
Receptacle. A contact device installed at the outlet for the connection of an attachment plug. A single receptacle is a single contact device with no other contact device on the same yoke. A multiple receptacle is two or more contact devices on the same yoke.
Receptacle Outlet. An outlet where one or more receptacles are installed.
Remote-Control Circuit. Any electric circuit that controls any other circuit through a relay or an equivalent device.
Separately Derived System. A premises wiring system whose power is derived from a battery, a solar photovoltaic system, or from a generator, transformer, or converter windings and that has no direct electrical connection, including a solidly connected grounded circuit conductor, to supply conductors originating in another system.
Service. The conductors and equipment for delivering energy from the electricity supply system to the wiring system of the premises served.
Service Cable. Service conductors made up in the form of a cable.
Service Conductors. The conductors from the service point to the service disconnecting means.
Service Drop. The overhead service conductors from the last pole or other aerial support to and including the splices, if any, connecting to the service-entrance conductors at the building or other structure.
Service-Entrance Cable. A single conductor or multiconductor assembly provided with or without an overall covering, primarily used for services, and is of the following types:
(A) Type SE. Type SE, having a flame-retardant, moisture resistant covering; and
(B) Type USE. Type USE, identified for underground use, having a moisture-resistant covering, but not required to have a flame-retardant covering. Cabled, single-conductor, Type USE constructions recognized for underground use may have a bare copper conductor cabled with the assembly. Type USE single, parallel, or cable conductor assemblies recognized for underground use may have a bare copper concentric conductor applied. These constructions do not require an outer overall covering.
Service-Entrance Conductors, Overhead System. The service conductors between the terminals of the service equipment and a point usually outside the building, clear of building walls, where joined by tap or splice to the service drop.
Service-Entrance Conductors, Underground System. The service conductors between the terminals of the service equipment and the point of connection to the service lateral.
Service Equipment. The necessary equipment, usually consisting of one or more circuit breakers or switches and fuses, and their accessories, connected to the load end of service conductors to a building or other structure, or an otherwise designated area, and intended to constitute the main control and cutoff of the supply.
Service Point. The point of connection between the facilities of the serving utility and the premises wiring.
Service Lateral. The underground service conductors between the street main, including any risers at a pole or other structure or from transformers, and the first point of connection to the service-entrance conductors in a terminal box or meter or other enclosure with adequate space inside or outside the building wall. Where there is no terminal box, meter, or other enclosure with adequate space, the point of connection shall be considered to be the point of entrance of the service conductors into the building.
Service Raceway. The raceway that encloses the service-entrance conductors.
Shielded Nonmetallic-Sheathed Cable (Type SNM). A factory assembly of two or more insulated conductors in an extruded core of moisture-resistant, flame-resistant nonmetallic material, covered with an overlapping spiral metal tape and wire shield and jacketed with an extruded moisture-, flame-, oil-, corrosion-, fungus-, and sunlight-resistant nonmetallic material.
Show Window. Any window used or designed to be used for the display of goods or advertising material, whether it is fully or partly enclosed or entirely open at the rear and whether or not it has a platform raised higher than the street floor level.
Signaling Circuit. Any electric circuit that energizes signaling equipment.
Storable Swimming or Wading Pool. A pool that is constructed on or above the ground and is capable of holding water to a maximum depth of 42 in. (1.07 m), or a pool with nonmetallic, molded polymeric walls or inflatable fabric walls regardless of dimension.
Suitable. Capable of performing with safety the particular function specified in these Orders.
(A) General-Use Switch. A switch intended for use in general distribution and branch circuits. It is rated in amperes, and it is capable of interrupting its rated current at its rated voltage.
(B) General-Use Snap Switch. A form of general-use switch so constructed that it can be installed in device boxes or on box covers, or otherwise used in conjunction with wiring systems recognized by this Order.
(C) Isolating Switch. A switch intended for isolating an electric circuit from the source of power. It has no interrupting rating, and it is intended to be operated only after the circuit has been opened by some other means.
(D) Motor Circuit Switch. A switch, rated in horsepower, capable of interrupting the maximum operating overload current of a motor of the same horsepower rating as the switch at the rated voltage.
Switchboard. A large single panel, frame, or assembly of panels on which are mounted, on the face or back or both, switches, overcurrent and other protective devices, buses, and usually instruments. Switchboards are generally accessible from the rear as well as from the front and are not intended to be installed in cabinets. (See “Panelboard.”)
Thermal Cutout. An overcurrent protective device that contains a heater element in addition to and affecting a renewable fusible member which opens the circuit. It is not designed to interrupt short-circuit currents.
Thermally Protected. (As applied to motors.) The words “Thermally Protected” appearing on the nameplate of a motor or motor-compressor indicate that the motor is provided with a thermal protector.
Thermal Protector. An inherent overheating protective device which is responsive to temperature and/or current and which protects the equipment against overheating due to overload or failure to start.
Utilization Equipment. Equipment which utilizes electric energy for electronic, electromechanical, chemical, heating, lighting, or similar purposes.
Vehicle. A device by which any person or property may be propelled, moved, or drawn, excepting a device moved by human power or used exclusively upon stationary rails or tracks.
Ventilated. Provided with a means to permit circulation of air sufficient to remove an excess of heat, fumes, or vapors.
Volatile Flammable Liquid. A flammable liquid having a flash point below 38oC (100oF) or a flammable liquid whose temperature is above its flash point, or a Class II combustible liquid having a vapor pressure not exceeding 276 kPa (40 psia) at 38oC (100oF) and whose temperature is above its flash point.
Voltage (Of A Circuit). The greatest root-mean-square (rms) (effective) difference of potential between any two conductors of the circuit concerned.
Some systems, such as 3-phase 4-wire, single-phase 3-wire, and 3-wire direct-current may have various circuits of various voltages.
Voltage, Nominal. A nominal value assigned to a circuit or system for the purpose of conveniently designating its voltage class (as 120/240 volts, 480Y/277 volts, 600 volts, etc.).
The actual voltage at which a circuit operates can vary from the nominal within a range that permits satisfactory operation of equipment. (See “Voltage Ratings for Electric Power Systems and Equipment (60 Hz),” ANSI C84.1-1977 and supplement C84.1a-1980.)
Voltage to Ground. For grounded circuits, the voltage between the given conductor and that point or conductor of the circuit that is grounded; for ungrounded circuits, the greatest voltage between the given conductor and any other conductor of the circuit.
Watertight. So constructed that moisture will not enter the enclosure.
Weatherproof. So constructed or protected that exposure to the weather will not interfere with successful operation.
Rainproof, raintight, or watertight equipment can fulfill the requirements for weatherproof, where varying weather conditions other than wetness, such as snow, ice, dust, or temperature extremes, are not a factor.
Wireways. Sheet-metal troughs with hinged or removable covers for housing and protecting electric wires and cable and in which conductors are laid in place after the wireway has been installed as a complete system.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
1. Amendment of subsection (a) filed 3-31-78; effective thirtieth day thereafter (Register 78, No. 13).
2. Amendment of subsection (a) filed 7-6-79 as procedural and organizational; effective upon filing (Register 79, No. 27).
3. Amendment filed 2-1-83; effective thirtieth day thereafter (Register 83, No 6).
4. Editorial correction of subsection (a) and NOTE filed 11-2-83 (Register 83, No. 45).
5. Amendment filed 8-27-86; effective thirtieth day thereafter (Register 86, No. 37).
6. Amendment of section and Note filed 5-5-2008; operative 5-5-2008. Submitted to OAL for printing only pursuant to Labor Code 142.3(a)(3) (Register 2008, No. 19).
7. New definitions of “Barricade,” “Cable Sheath,” “Circuit,” “Current-Carrying Part,” “Fall Protection,” “Minimum Approach Distance,” “Qualified Electrical Worker,” “Qualified Line Clearance Tree Trimmer” and “Qualified Tree Worker” filed 2-27-2018; operative 4-1-2018 (Register 2018, No. 9).

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