This Code does not cover the following: ARTICLE 90 1 Installations in ships, watercraft other than floating build- Introduction ings, railway rolling stock, aircraft, or automotive vehicles other than mobile homes and recreational vehicles The purpose of this Code is dicates that the Code does not cover installations in ships, the practical safeguarding of persons and property from portions of this Code are incorporated by reference into hazards arising from the use of electricity.
This Code contains provisions that are con- electrical trailing cable sidered necessary for safety. Compliance therewith and 3 Installations of railways for generation, transformation, proper maintenance results in an installation that is essen- transmission, or distribution of power used exclusively tially free from hazard but not necessarily efficient, conve- for operation of rolling stock or installations used ex- nient, or adequate for good service or future expansion of clusively for signaling and communications purposes electrical use.
This occurs because initial wiring such installations did not provide for increases in the use of electricity. An initial adequate installation and reasonable provisions for 5 Installations under the exclusive control of an electric system changes provide for future increases in the use of utility where such installations electricity.
The re- sociated metering, or quirements in this Code address the fundamental principles b. Are on property owned or leased by the electric of protection for safety contained in Section of Inter- utility for the purpose of communications, metering, national Electrotechnical Commission Standard , generation, control, transformation, transmission, or Electrical Installations of Buildings. Are located in legally established easements or Informative annexes are not part of the requirements of rights-of-way, or this Code but are included for informational purposes only.
Are located by other written agreements either des- ignated by or recognized by public service commis- sions, utility commissions, or other regulatory agen- Chapter 1 — General. These Chapter 2 — Wiring and Protection Applies generally written agreements shall be limited to installations to all electrical Chapter 3 — Wiring Methods and Materials installations for the purpose of communications, metering, gen- eration, control, transformation, transmission, or Chapter 4 — Equipment for General Use distribution of electric energy where legally estab- lished easements or rights-of-way cannot be ob- Chapter 5 — Special Occupancies tained.
These installations shall be limited to federal lands, Native American reservations through the Supplements or modifies Chapter 6 — Special Equipment Chapters 1 through 4 U. Department of the Interior Bureau of Indian Chapter 7 — Special Conditions Affairs, military bases, lands controlled by port au- thorities and state agencies and departments, and lands owned by railroads. Utilities may be subject to compliance with codes and standards covering their regulated activities as Figure Additional infor- mation can be found through consultation with the appropriate governmental bodies, such as state regulatory commissions, the This Code is intended to be suitable Federal Energy Regulatory Commission, and the Federal Com- for mandatory application by governmental bodies that ex- munications Commission.
The authority having jurisdiction insurance inspectors. The authority having jurisdiction for for enforcing this Code may grant exception for the instal- enforcement of the Code has the responsibility for making lation of conductors and equipment that are not under the interpretations of the rules, for deciding on the approval of exclusive control of the electric utilities and are used to equipment and materials, and for granting the special per- connect the electric utility supply system to the service mission contemplated in a number of the rules.
This Code is divided into the in- This Code may require new products, constructions, or troduction and nine chapters, as shown in Figure Chap- materials that may not yet be available at the time the Code ters 1, 2, 3, and 4 apply generally; Chapters 5, 6, and 7 apply is adopted.
In such event, the authority having jurisdiction to special occupancies, special equipment, or other special may permit the use of the products, constructions, or mate- conditions. These latter chapters supplement or modify the rials that comply with the most recent previous edition of general rules.
Chapters 1 through 4 apply except as amended this Code adopted by the jurisdiction. Chapter 8 covers communications systems and is not Mandatory rules of this Code are ter 8. B Permissive Rules. Permissive rules of this Code are ing paragraph and that requires suitability for installation in those that identify actions that are allowed but not required, accordance with this Code.
Informational Note No. Explanatory material, such as an informative list of product safety standards for electrical references to other standards, references to related sections equipment. Such notes are informational only and are not enforceable A Future Expansion and Convenience.
Plans and as requirements of this Code. Distribution vided as a guide to indicate the source of the extracted text. B Number of Circuits in Enclosures. Copies of this manual can confined in a single enclosure be varyingly restricted. Lim- be obtained from NFPA. D Informative Annexes. Nonmandatory information relative to the use of the NEC is provided in informative Informative annexes are not part of the enforce- able requirements of the NEC, but are included for infor- A Measurement System of Preference.
For the purpose mation purposes only. SI units shall appear first, and Code, formal interpretation procedures have been estab- inch-pound units shall immediately follow in parentheses. The cases given items of equipment and materials referred to in this Code, in Where the actual measured size of a prod- uct is not the same as the nominal size, trade size designa- properly equipped and qualified for experimental testing, tors shall be used rather than dimensions. Trade practices inspections of the run of goods at factories, and service- shall be followed in all cases.
This avoids the necessity for repetition of examinations by different 2 Extracted Material. Where material is extracted from examiners, frequently with inadequate facilities for such another standard, the context of the original material shall work, and the confusion that would result from conflicting not be compromised or violated.
Any editing of the ex- reports on the suitability of devices and materials examined tracted text shall be confined to making the style consistent for a given purpose.
It is the intent of this Code that factory-installed inter- 3 Industry Practice. Where industry practice is to ex- nal wiring or the construction of equipment need not be press units in inch-pound units, the inclusion of SI units inspected at the time of installation of the equipment, ex- shall not be required. Where a negative impact on safety would re- recognized as having the facilities described in the preced- sult, soft conversion shall be used.
D Compliance. Conversion from inch-pound units to SI sizes used in the original measurement. Soft conversion is units shall be permitted to be an approximate conversion. Chapter 1 General. Acceptable to the authority having jurisdiction. A device intended to the proper application of this Code. It is not intended to to provide protection from the effects of arc faults by rec- include commonly defined general terms or commonly de- ognizing characteristics unique to arcing and by function- fined technical terms from related codes and standards.
In ing to de-energize the circuit when an arc fault is detected. Other definitions are Askarel. A generic term for a group of nonflammable syn- included in the article in which they are used but may be thetic chlorinated hydrocarbons used as electrical insulating referenced in Article Part I of this article contains definitions intended to Informational Note: Askarels of various compositional apply wherever the terms are used throughout this Code.
Under arcing conditions, the gases pro- Part II contains definitions applicable only to articles and duced, while consisting predominantly of noncombustible parts of articles specifically covering installations and hydrogen chloride, can include varying amounts of com- bustible gases, depending on the askarel type.
Attachment Plug Plug Cap Plug. A device that, by I. General insertion in a receptacle, establishes a connection between the conductors of the attached flexible cord and the conduc- Accessible as applied to equipment.
Admitting close tors connected permanently to the receptacle. An organization, office, or individual responsible for enforcing the require- Accessible as applied to wiring methods. Capable of ments of a code or standard, or for approving equipment, being removed or exposed without damaging the building materials, an installation, or a procedure. Capable of be- broad manner, since jurisdictions and approval agencies ing reached quickly for operation, renewal, or inspections vary, as do their responsibilities.
Where public safety is without requiring those to whom ready access is requisite primary, the authority having jurisdiction may be a federal, state, local, or other regional department or individual such as to actions such as to use tools, to climb over or remove a fire chief; fire marshal; chief of a fire prevention bureau, obstacles, or to resort to portable ladders, and so forth. Power conversion equipment trical inspector; or others having statutory authority.
For insur- ance purposes, an insurance inspection department, rating bu- that provides a means of adjusting the speed of an electric reau, or other insurance company representative may be the motor.
In many circumstances, the property owner or his or her designated agent assumes the role Informational Note: A variable frequency drive is one type of the authority having jurisdiction; at government installa- of electronic adjustable speed drive that controls the rota- tions, the commanding officer or departmental official may be tional speed of an ac electric motor by controlling the fre- the authority having jurisdiction.
Performing a function without the necessity of Adjustable Speed Drive System. A combination of an ad- human intervention. An area including a basin with one or more of equipment. The maximum current, in amperes, that a con- similar plumbing fixtures. Interconnected battery subsystems con- without exceeding its temperature rating. Utilization equipment, generally other than in- ers, and can include inverters, converters, and associated dustrial, that is normally built in standardized sizes or types electrical equipment.
Bonded Bonding. Connected to establish electrical con- Circuit Breaker. A device designed to open and close a tinuity and conductivity. A reliable conductor to to itself when properly applied within its rating.
Informational Note: The automatic opening means can be integral, direct acting with the circuit breaker, or remote Bonding Jumper, Equipment. The connection between two from the circuit breaker. Adjustable as applied to circuit breakers. A qualifying Bonding Jumper, Main. The connection between the term indicating that the circuit breaker can be set to trip at grounded circuit conductor and the equipment grounding various values of current, time, or both, within a predeter- conductor at the service.
Bonding Jumper, System. The connection between the Instantaneous Trip as applied to circuit breakers. A grounded circuit conductor and the supply-side bonding qualifying term indicating that no delay is purposely intro- jumper, or the equipment grounding conductor, or both, at a duced in the tripping action of the circuit breaker.
Inverse Time as applied to circuit breakers. A qualifying term indicating that there is purposely introduced a delay in Branch Circuit. The circuit conductors between the final the tripping action of the circuit breaker, which delay de- overcurrent device protecting the circuit and the outlet s.
Branch Circuit, Appliance. A branch circuit that supplies Nonadjustable as applied to circuit breakers. A quali- energy to one or more outlets to which appliances are to be fying term indicating that the circuit breaker does not have connected and that has no permanently connected lumi- any adjustment to alter the value of the current at which it naires that are not a part of an appliance.
Branch Circuit, General-Purpose. A branch circuit that Setting of circuit breakers. The value of current, time, or supplies two or more receptacles or outlets for lighting and both, at which an adjustable circuit breaker is set to trip. Clothes Closet. A nonhabitable room or space intended Branch Circuit, Individual.
A branch circuit that supplies primarily for storage of garments and apparel. Communications Equipment. The electronic equipment Branch Circuit, Multiwire.
A branch circuit that consists that performs the telecommunications operations for the of two or more ungrounded conductors that have a voltage transmission of audio, video, and data, and includes power between them, and a grounded conductor that has equal equipment e.
Communications Raceway. An enclosed channel of non- Building. A structure that stands alone or that is cut off metallic materials designed expressly for holding commu- from adjoining structures by fire walls with all openings nications wires and cables, typically communications wires therein protected by approved fire doors. An enclosure that is designed for either surface mounting or flush mounting and is provided with a frame, Concealed.
Rendered inaccessible by the structure or finish mat, or trim in which a swinging door or doors are or can of the building. Informational Note: Wires in concealed raceways are con- sidered concealed, even though they may become acces- Cable Routing Assembly. A single channel or connected sible by withdrawing them. A conductor having no covering or elec- nications wires and cables, optical fiber cables, data cables trical insulation whatsoever.
A conductor encased within material tions equipment, Class 2 and Class 3 cables, and power- of composition or thickness that is not recognized by this limited fire alarm cables. Code as electrical insulation. Charge Controller.
Equipment that controls dc voltage or Conductor, Insulated. A conductor encased within mate- dc current, or both, and that is used to charge a battery or rial of composition and thickness that is recognized by this other energy storage device. Conduit Body. A separate portion of a conduit or tubing Dusttight. Constructed so that dust will not enter the en- system that provides access through a removable cover s closing case under specified test conditions.
Operation at a substantially constant 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. Duty, Intermittent. Operation for alternate intervals of 1 Connector, Pressure Solderless. A device that estab- load and no load; or 2 load and rest; or 3 load, no load, lishes a connection between two or more conductors or and rest.
Intermittent operation in which the load of mechanical pressure and without the use of solder. Continuous Load. A load where the maximum current is Duty, Short-Time.
Operation at a substantially constant expected to continue for 3 hours or more. Control Circuit. The circuit of a control apparatus or sys- Duty, Varying. Operation at loads, and for intervals of tem that carries the electric signals directing the perfor- time, both of which may be subject to wide variation. Dwelling, One-Family. A building that consists solely of Controller. A device or group of devices that serves to one dwelling unit.
A building that consists solely of delivered to the apparatus to which it is connected. Cooking Unit, Counter-Mounted. A cooking appliance Dwelling, Multifamily. A building that contains three or designed for mounting in or on a counter and consisting of more dwelling units. Dwelling Unit. A single unit, providing complete and in- dependent living facilities for one or more persons, includ- Coordination Selective. Localization of an overcurrent ing permanent provisions for living, sleeping, cooking, and condition to restrict outages to the circuit or equipment sanitation.
An intentionally for the full range of available overcurrents, from overload constructed, low-impedance electrically conductive path to the maximum available fault current, and for the full designed and intended to carry current under ground-fault range of overcurrent protective device opening times asso- conditions from the point of a ground fault on a wiring ciated with those overcurrents.
Conductors drawn the operation of the overcurrent protective device or from a copper-clad aluminum rod, with the copper metal- ground-fault detectors. An enclosure designed for surface mounting electric power to the connected loads, that are external to that has swinging doors or covers secured directly to and and not controlled by an interactive system.
Electric Sign. A fixed, stationary, or portable self- Dead Front. Without live parts exposed to a person on the contained, electrically illuminated utilization equipment operating side of the equipment.
The ratio of the maximum demand of a attract attention. Systems of illumination uti- system or the part of the system under consideration. A unit of an electrical system, other than a conduc- lamps, or neon tubing.
An overcurrent protective function. A device, or group of devices, or vides current-sensing, electronically derived time—current other means by which the conductors of a circuit can be characteristics, energy to initiate tripping, and an interrupting disconnected from their source of supply.
Such fuses may or may not operate in a current-limiting fash- Garage. A building or portion of a building in which one or ion, depending on the type of control selected. Surrounded by a case, housing, fence, or wall s that prevents persons from accidentally contacting ener- Informational Note: For commercial garages, repair and gized parts.
The case or housing of apparatus, or the fence Ground. The earth. An unintentional, electrically conductive from accidentally contacting energized parts or to protect connection between an ungrounded conductor of an electri- the equipment from physical damage. Electrically connected to, or is, a source of Grounded Grounding. Connected connecting to voltage. A general term, including fittings, devices, appli- ances, luminaires, apparatus, machinery, and the like used as a Grounded, Solidly. Connected to ground without inserting part of, or in connection with, an electrical installation.
Explosionproof Equipment. Equipment enclosed in a case Grounded Conductor. A system or circuit conductor that that is capable of withstanding an explosion of a specified is intentionally grounded. A device in- ignition of a specified gas or vapor surrounding the enclo- tended for the protection of personnel that functions to de- sure by sparks, flashes, or explosion of the gas or vapor energize a circuit or portion thereof within an established within, and that operates at such an external temperature period of time when a current to ground exceeds the values that a surrounding flammable atmosphere will not be ig- established for a Class A device.
Fault Circuit Interrupters. Exposed as applied to live parts. Capable of being in- Ground-Fault Current Path. An electrically conductive advertently touched or approached nearer than a safe dis- path from the point of a ground fault on a wiring system tance by a person. Informational Note: This term applies to parts that are not suitably guarded, isolated, or insulated.
Informational Note: Examples of ground-fault current paths are any combination of equipment grounding conductors, me- Exposed as applied to wiring methods. On or attached tallic raceways, metallic cable sheaths, electrical equipment, to the surface or behind panels designed to allow access. Capable of being operated without metal ducting; reinforcing steel; shields of communications exposing the operator to contact with live parts. All circuit conductors between the service equip- Ground-Fault Protection of Equipment.
A system in- ment, the source of a separately derived system, or other tended to provide protection of equipment from damaging power supply source and the final branch-circuit overcur- line-to-ground fault currents by operating to cause a discon- rent device. This protection is provided at current levels less Festoon Lighting.
A string of outdoor lights that is sus- than those required to protect conductors from damage pended between two points. The conduc- part of a wiring system that is intended primarily to per- tive path s that provides a ground-fault current path and con- form a mechanical rather than an electrical function. Grounding Electrode. A conductor used to ible and not more than 15 m 50 ft distant from the other. An assembly of two or more trode system. Covered, shielded, fenced, enclosed, or other- load relays, fused disconnect switches, and circuit breakers; wise protected by means of suitable covers, casings, barri- 2 control circuit components only, such as push buttons, ers, rails, screens, mats, or platforms to remove the likeli- pilot lights, selector switches, timers, switches, and control hood of approach or contact by persons or objects to a point relays; 3 a combination of power and control circuit com- of danger.
These components, with associated wiring and ter- Guest Room. An accommodation combining living, sleep- minals, are mounted on, or contained within, an enclosure ing, sanitary, and storage facilities within a compartment. The industrial control panel does not include the con- Guest Suite.
An accommodation with two or more con- trolled equipment. An electric power production system sanitary, and storage facilities. Handhole Enclosure. An enclosure for use in underground systems, provided with an open or closed bottom, and sized Interrupting Rating.
The highest current at rated voltage to allow personnel to reach into, but not enter, for the pur- that a device is identified to interrupt under standard test pose of installing, operating, or maintaining equipment or conditions. Informational Note: Equipment intended to interrupt cur- rent at other than fault levels may have its interrupting Hermetic Refrigerant Motor-Compressor.
A combina- rating implied in other ratings, such as horsepower or tion consisting of a compressor and motor, both of which locked rotor current. Intersystem Bonding Termination. A device that pro- vides a means for connecting intersystem bonding conduc- Hoistway.
Any shaftway, hatchway, well hole, or other ver- tors for communications systems to the grounding electrode tical opening or space in which an elevator or dumbwaiter system.
Isolated as applied to location. Not readily accessible Hybrid System. A system comprised of multiple power to persons unless special means for access are used. These power sources could include photovoltaic, Kitchen.
An area with a sink and permanent provisions for wind, micro-hydro generators, engine-driven generators, food preparation and cooking. Energy storage systems Labeled. Equipment or materials to which has been at- such as batteries, flywheels, or superconducting magnetic tached a label, symbol, or other identifying mark of an storage equipment do not constitute a power source for the organization that is acceptable to the authority having juris- purpose of this definition.
The energy regenerated by an diction and concerned with product evaluation, that main- overhauling descending elevator does not constitute a tains periodic inspection of production of labeled equip- power source for the purpose of this definition. Recognizable as mance in a specified manner. An outlet intended for the direct connec- ticular Code requirement. Lighting Track Track Lighting. A manufactured assem- Neutral Conductor. The conductor connected to the neu- bly designed to support and energize luminaires that are tral point of a system that is intended to carry current under capable of being readily repositioned on the track.
Its normal conditions. The common point on a wye-connection in a tions of track. Equipment, materials, or services included in a list tem, or midpoint of a single-phase portion of a 3-phase delta published by an organization that is acceptable to the au- system, or a midpoint of a 3-wire, direct-current system. Requiring human intervention to perform a a specified purpose.
Nonlinear Load. A load where the wave shape of the Informational Note: The means for identifying listed equipment may vary for each organization concerned with steady-state current does not follow the wave shape of the product evaluation, some of which do not recognize equip- applied voltage.
Live Parts. Energized conductive components. A point on the wiring system at which current is Location, Damp. Locations protected from weather and taken to supply utilization equipment.
An arrangement of incandescent lamps, subject to moderate degrees of moisture. Any current in excess of the rated current of basements, some barns, and some cold-storage warehouses.
It may result Location, Dry. A location not normally subject to damp- from overload, short circuit, or ground fault. A location classified as dry may be tem- Informational Note: A current in excess of rating may be porarily subject to dampness or wetness, as in the case of a accommodated by certain equipment and conductors for a building under construction.
Therefore, the rules for overcurrent protection are specific for particular situations. Location, Wet. Installations underground or in concrete slabs or masonry in direct contact with the earth; in loca- Overcurrent Protective Device, Branch-Circuit.
A device tions subject to saturation with water or other liquids, such capable of providing protection for service, feeder, and branch as vehicle washing areas; and in unprotected locations ex- circuits and equipment over the full range of overcurrents be- posed to weather.
Such devices are provided with interrupting ratings appropriate for the in- Luminaire. A complete lighting unit consisting of a light tended use but no less than amperes. A de- power supply. It may also include parts to protect the light vice intended to provide limited overcurrent protection for source or the ballast or to distribute the light.
A lampholder specific applications and utilization equipment such as lu- itself is not a luminaire. This limited protection is in addi- tion to the protection provided in the required branch cir- Motor Control Center. An assembly of one or more en- cuit by the branch-circuit overcurrent protective device. Operation of equipment in excess of normal, full-load rating, or of a conductor in excess of rated ampac- Multioutlet Assembly.
A type of surface, flush, or free- ity that, when it persists for a sufficient length of time, standing raceway designed to hold conductors and recep- would cause damage or dangerous overheating.
A fault, tacles, assembled in the field or at the factory. A single panel or group of panel units de- Raintight. Constructed or protected so that exposure to a signed for assembly in the form of a single panel, including beating rain will not result in the entrance of water under buses and automatic overcurrent devices, and equipped specified test conditions. A receptacle is a contact device installed at the box placed in or against a wall, partition, or other support; outlet for the connection of an attachment plug.
A single and accessible only from the front. A multiple receptacle is two or Photovoltaic PV System. The total components and sub- more contact devices on the same yoke.
Receptacle Outlet. An outlet where one or more recep- tacles are installed. A compartment or chamber to which one or more air ducts are connected and that forms part of the air distri- Remote-Control Circuit. Any electrical circuit that controls bution system. Retrofit Kit. A general term for a complete subassembly Power Outlet. An enclosed assembly that may include re- of parts and devices for field conversion of utilization ceptacles, circuit breakers, fuseholders, fused switches, equipment.
Equipment enclosed in a case or vehicles, park trailers, or boats or to serve as a means for cabinet that is provided with a means of sealing or locking distributing power required to operate mobile or tempo- so that live parts cannot be made accessible without open- rarily installed equipment.
Premises Wiring System. Interior and exterior wiring, Informational Note: The equipment may or may not be including power, lighting, control, and signal circuit wiring operable without opening the enclosure. Separately Derived System. An electrical source, other This includes a wiring from the service point or power than a service, having no direct connection s to circuit source to the outlets or b wiring from and including the conductors of any other electrical source other than those power source to the outlets where there is no service point.
Such wiring does not include wiring internal to appli- Service. The conductors and equipment for delivering elec- ances, luminaires, motors, controllers, motor control cen- tric energy from the serving utility to the wiring system of ters, and similar equipment. Informational Note: Power sources include, but are not Service Cable.
Service conductors made up in the form of limited to, interconnected or stand-alone batteries, solar photovoltaic systems, other distributed generation systems, a cable.
Service Conductors. The conductors from the service point Qualified Person. One who has skills and knowledge re- to the service disconnecting means. The overhead conductors equipment and installations and has received safety training between the service point and the first point of connection to recognize and avoid the hazards involved. Service Conductors, Underground. The underground con- ductors between the service point and the first point of con- Raceway.
An enclosed channel of metallic or nonmetallic nection to the service-entrance conductors in a terminal box, materials designed expressly for holding wires, cables, or bus- meter, or other enclosure, inside or outside the building wall. Informational Note: Where there is no terminal box, meter, Informational Note: A raceway is identified within specific or other enclosure, the point of connection is considered to article definitions.
Constructed, protected, or treated so as to pre- vent rain from interfering with the successful operation of Service Drop. The overhead conductors between the utility the apparatus under specified test conditions. Service-Entrance Conductors, Overhead System. The vents continued flow of follow current while remaining ca- service conductors between the terminals of the service pable of repeating these functions. A protective device for drop or overhead service conductors.
The necessary equipment, usually con- current device, including SPDs located at the branch panel. Service Lateral. The underground conductors between the utility electric supply system and the service point. Switch, Bypass Isolation. A manually operated device used in conjunction with a transfer switch to provide a Service Point. The point of connection between the facili- means of directly connecting load conductors to a power ties of the serving utility and the premises wiring.
Informational Note: The service point can be described as the point of demarcation between where the serving utility Switch, General-Use. A switch intended for use in general ends and the premises wiring begins.
The serving utility distribution and branch circuits. It is rated in amperes, and generally specifies the location of the service point based it is capable of interrupting its rated current at its rated on the conditions of service. Short-Circuit Current Rating. The prospective symmetri- Switch, General-Use Snap. A form of general-use switch cal fault current at a nominal voltage to which an apparatus constructed so that it can be installed in device boxes or on or system is able to be connected without sustaining dam- box covers, or otherwise used in conjunction with wiring age exceeding defined acceptance criteria.
Show Window. Any window used or designed to be used for the display of goods or advertising material, whether it Switch, Isolating. A switch intended for isolating an elec- is fully or partly enclosed or entirely open at the rear and trical circuit from the source of power.
It has no interrupt- whether or not it has a platform raised higher than the street ing rating, and it is intended to be operated only after the floor level. Signaling Circuit. Any electrical circuit that energizes sig- Switch, Motor-Circuit. A switch rated in horsepower that naling equipment. The written consent of the authority switch at the rated voltage. Switch, Transfer. An automatic or nonautomatic device for Structure. That which is built or constructed.
An enclosed assemblage of equipment e. A large single panel, frame, or assembly of transformers through which electric energy is passed for panels on which are mounted on the face, back, or both, the purpose of distribution, switching, or modifying its switches, overcurrent and other protective devices, buses, characteristics.
These assemblies are generally Surge Arrester. A protective device for limiting surge volt- accessible from the rear as well as from the front and are ages by discharging or bypassing surge current; it also pre- not intended to be installed in cabinets. An assembly completely enclosed on all sides Informational Note: Some systems, such as 3-phase and top with sheet metal except for ventilating openings 4-wire, single-phase 3-wire, and 3-wire direct current, may have various circuits of various voltages.
A nominal value assigned to a circuit or connections. The assembly may include control and auxil- system for the purpose of conveniently designating its volt- iary devices. Access to the interior of the enclosure is pro- age class e. Switchgear rated below that permits satisfactory operation of equipment. Voltage to Ground. For grounded circuits, the voltage be- Thermal Protector as applied to motors.
A protective tween the given conductor and that point or conductor of device for assembly as an integral part of a motor or motor- the circuit that is grounded; for ungrounded circuits, the compressor that, when properly applied, protects the motor greatest voltage between the given conductor and any other against dangerous overheating due to overload and failure conductor of the circuit.
Constructed so that moisture will not enter the Informational Note: The thermal protector may consist of enclosure under specified test conditions. Constructed or protected so that exposure to the weather will not interfere with successful operation. Thermally Protected as applied to motors. The words Thermally Protected appearing on the nameplate of a motor Informational Note: Rainproof, raintight, or watertight or motor-compressor indicate that the motor is provided equipment can fulfill the requirements for weatherproof with a thermal protector.
Not connected to ground or to a conductive body that extends the ground connection. A power supply used to provide alternating current power to a load for some period Part II contains definitions applicable only to the articles of time in the event of a power failure. Informational Note: In addition, it may provide a more The definitions in Part I are intended to apply wherever constant voltage and frequency supply to the load, reducing the effects of voltage and frequency variations.
An inverter intended for use specifically covering installations and equipment operating in parallel with an electric utility to supply common loads at over volts, nominal. Electronically Actuated Fuse. An overcurrent protective Utilization Equipment. Equipment that utilizes electric device that generally consists of a control module that pro- energy for electronic, electromechanical, chemical, heating, vides current sensing, electronically derived time—current lighting, or similar purposes.
Provided with a means to permit circulation of ing module that interrupts current when an overcurrent oc- air sufficient to remove an excess of heat, fumes, or vapors. Electronically actuated fuses may or may not operate Volatile Flammable Liquid. Informational Note: A fuse comprises all the parts that Voltage of a circuit.
The greatest root-mean-square rms form a unit capable of performing the prescribed functions. Controlled Vented Power Fuse. A fuse with provision for fuse link so that arc interruption by severing of the fuse controlling discharge circuit interruption such that no solid link or by opening of the contacts will occur under oil. Oil Switch. A switch having contacts that operate under oil Informational Note: The fuse is designed so that dis- or askarel or other suitable liquid.
A specific device or combina- path of the discharge or propagate a flashover to or between grounded members or conduction members in the path of tion of devices designed to bypass a regulator. Expulsion Fuse Unit Expulsion Fuse.
A vented fuse unit in which the expulsion effect of gases produced by the arc ARTICLE and lining of the fuseholder, either alone or aided by a Requirements for Electrical Installations spring, extinguishes the arc. His successor, Jim Pauley, repeated the same thing. You have to supply information: your email address, first and last names, industry, job function, country, address, city, zip code, and phone number. As any good marketer knows, this is valuable information that will convert into future sales and profits.
If you want to look up an article in the middle of a chapter, the best you can do is use the table of contents to go to the beginning of that chapter and then flip through the pages one by one until you find what you need.
What this means is that to gain restricted access to public law you must surrender valuable marketing information to a private company. And then, once you do, they pressure you into buying an expensive usable copy. So, if you get your code adopted into law, it seems the government may be obligated to direct thousands of people into your sales and marketing funnel using taxpayer dollars. We are waiting to see if the governments agree that this arrangement is legitimate, especially in light of the previous court ruling mentioned earlier in this article.
The matter is not yet settled. But this will be a court case worth following. Theft of private property is illegal. We are going to have to wait and see if the courts rule whether the NEC, once adopted into law, is private property or not. They will tell us what we are allowed to do. Privitizing codes which have the force of law is unsupportable. There is no safety in the unknown. I think that if the NFPA is going to sue anyone they should be suing the states adopting their code into law.
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