Article 100 of the National Electrical Code (NEC) provides definitions of terms that are used throughout the code. Here are a few of the terms defined in NEC Article 100:
NEC Article 100 Definitions
- “Approved”: Acceptable to the authority having jurisdiction (AHJ).
- “Authority having jurisdiction (AHJ)”: The organization, office, or individual responsible for approving equipment, materials, an installation, or a procedure.
- “Conductor”: A wire or other electrical conductive material that is used to transmit electricity.
- “Grounded”: Connected to earth or to some conducting body that serves in place of the earth.
- “Grounding conductor”: A conductor used to connect equipment or the grounded circuit of an electrical system to a grounding electrode or electrodes.
- “Overcurrent”: A current in excess of the rated current of an electrical device or conductor.
- “System”: A group of electrical components connected together to perform a specific function.
- “Ungrounded conductor”: A conductor that is not intentionally grounded.
- “Wiring method”: The specific technique used to install and secure conductors in place. Examples of wiring methods include conduit, cable, and busways.
- “Equipment”: Electrical devices or appliances, such as circuit breakers, transformers, and motors.
- “Load”: The electrical demand placed on a system or conductor.
- “Service”: The electrical system, including the service equipment and the service conductors, that provide electricity to a building or structure.
- “Circuit”: A path that electricity follows through a system. A circuit can include conductors, equipment, and other electrical components.
- “Circuit breaker”: A device that is used to open or close a circuit under normal or fault conditions.
Voltage, Nominal as per NEC
Nominal voltage is the voltage that is used to identify and describe an electrical system or component. It is typically based on the rated voltage of the system or component and is used as a reference for design and operation. The National Electrical Code (NEC) includes provisions for the use of nominal voltage in electrical systems, in order to ensure the safety and performance of the system and its components.
Voltage to Ground as per NEC
Voltage to ground is the voltage of an electrical conductor or point in an electrical system with respect to ground or earth. It is used to measure the potential difference between the conductor or point and ground, and it is an important factor in determining the safety of an electrical system. The National Electrical Code (NEC) includes provisions for the measurement and limits of voltage to ground in electrical systems, in order to ensure the safety of the system and its components.
Surge-Protective Device (SPD) as per NEC
A surge-protective device (SPD) is an electrical device that is used to protect against transient overvoltages, also known as surges or spikes, in an electrical system. It is designed to divert or dissipate excess voltage to ground in order to protect the electrical system and its components from damage. The National Electrical Code (NEC) includes provisions for the installation and use of surge-protective devices in electrical systems, in order to protect against transient overvoltages and ensure the safety and reliability of the electrical system.
Short-Circuit Current Rating as per NEC
The short-circuit current rating (SCCR) of an electrical system or component is the maximum level of short-circuit current that the system or component is able to withstand without failing or suffering permanent damage.
It is typically expressed in amperes (amps) and is used to determine the suitability of the system or component for a particular application. The National Electrical Code (NEC) includes provisions for determining the short-circuit current ratings of electrical systems and components, in order to ensure their safety and reliability.
Surge-Protective Device (SPD) as per NEC
A surge-protective device (SPD) is an electrical device that is used to protect against transient overvoltages, also known as surges or spikes, in an electrical system. It is designed to divert or dissipate excess voltage to ground in order to protect the electrical system and its components from damage. The National Electrical Code (NEC) includes provisions for the installation and use of surge-protective devices in electrical systems, in order to protect against transient overvoltages and ensure the safety and reliability of the electrical system.
Service Lateral as per NEC
A service lateral is a section of an electrical distribution system that extends from the utility’s distribution lines to the service entrance of a building. It includes the service conductors, as well as any other components, such as meters and service equipment, that are used to bring electrical power to the building. The National Electrical Code (NEC) includes provisions for the installation and protection of service laterals, in order to ensure the safety and reliability of the electrical service to the building.
Service Conductors as per NEC
Service conductors are the electrical conductors that are used to bring electrical power from the utility’s distribution system to the service entrance of a building. The National Electrical Code (NEC) includes provisions for the installation and protection of service conductors, in order to ensure the safety and reliability of the electrical service to the building.
Receptacle as per NEC
A receptacle is an electrical outlet that is designed to receive the plug of an electrical cord. The National Electrical Code (NEC) includes provisions for the installation, use, and protection of receptacles in electrical systems, in order to ensure the safety and convenience of the users of the electrical system.
Plenum as per NEC
A plenum is a compartment or chamber in a building that is used for the circulation of air, as part of the heating, ventilation, and air conditioning (HVAC) system. The National Electrical Code (NEC) includes provisions for the installation of electrical conductors and equipment in plenums, in order to ensure the safety and performance of the electrical system and the HVAC system.
Panelboard as per NEC
A panelboard is a type of electrical distribution panel that is used to distribute power to multiple circuits. It consists of a cabinet or enclosure that contains circuit breakers or fuses, as well as busbars and other components that are used to distribute the electrical power.
Nonlinear Load as per NEC
A nonlinear load is an electrical load that consumes electrical power in a manner that is not proportional to the voltage and frequency of the power. It is characterized by a nonlinear relationship between the voltage and current in the circuit.
Neutral Point as per NEC
A neutral point, as defined by the National Electrical Code (NEC), is the point within an electrical system that is intended to be at ground potential and that is used to complete the electrical circuit.
Neutral Conductor as per NEC
A neutral conductor is a conductor in an electrical system that is intended to be at ground potential and that is used to complete the electrical circuit.
Luminaire as per NEC
A luminaire, as defined by the National Electrical Code (NEC), is a complete lighting unit that includes a lamp or lamps and the parts that are necessary for the proper functioning of the lamp(s).
Interrupting Rating as per NEC
The interrupting rating of an electrical device is the maximum current that the device is capable of interrupting safely under standard test conditions. It is typically expressed in amperes (amps), and it is used to determine the suitability of the device for a particular application.
In the National Electrical Code (NEC), the interrupting rating of an electrical device, such as a circuit breaker or fuse, is used to determine the size and type of the device that is required for a given electrical circuit. The NEC includes tables that provide the interrupting ratings for different types and sizes of electrical devices, based on the voltage and the type of circuit that the device will be protecting.
The interrupting rating of an electrical device is an important factor in ensuring the safety and reliability of the electrical system. It helps to prevent overloading and reduce the risk of electrical fires by ensuring that the device is capable of interrupting an overcurrent or short circuit.
Hoistway as per NEC
A hoistway is a shaft or enclosure in a building that is used to guide a hoist or elevator. It typically extends from the bottom floor to the top floor of a building, and it is enclosed on all sides to protect the hoist or elevator and its passengers from falling.
The National Electrical Code (NEC) includes provisions for the electrical installations in hoistways, including requirements for the wiring methods, outlets, lighting, and other electrical components. These provisions are intended to ensure the safety of the hoist or elevator and its passengers, as well as to protect the hoistway from electrical hazards.
Ground-Fault Circuit Interrupter (GFCI) as per NEC
A ground-fault circuit interrupter (GFCI) is a safety device that is used in electrical systems to protect against the risk of electric shock. It is designed to detect ground faults, which are unintentional electrical paths between a conductor and the ground, and to interrupt the flow of electricity to prevent electric shock.
GFCIs are required by the National Electrical Code (NEC) in many locations where there is a risk of electric shock, such as in bathrooms, kitchens, and outdoors. They are typically installed in outlets, and they can also be installed in circuit breaker panels or as part of portable extension cords.
GFCIs work by comparing the current flowing through the hot and neutral conductors of an electrical circuit. If the GFCI detects an imbalance between the two conductors, which could indicate a ground fault, it will trip and interrupt the flow of electricity. This helps to prevent electric shock and reduce the risk of electrical fires.
Ground Fault as per NEC
A ground fault is an electrical fault in which there is an unintentional electrical path between a conductor and the ground. It can occur when a conductor becomes damaged or degraded and the insulation is no longer sufficient to prevent an electrical current from flowing to the ground.
Ground faults can be hazardous because they can allow electricity to flow through unintended paths, such as through a person’s body, potentially causing electric shock or injury. They can also cause overheating and damage to electrical equipment.
The National Electrical Code (NEC) includes provisions for the detection and protection of ground faults in electrical systems. These provisions include requirements for ground fault circuit interrupters (GFCIs), which are devices that are designed to detect ground faults and interrupt the flow of electricity to prevent electric shock. The NEC also includes requirements for the installation and maintenance of grounding systems, which are used to safely conduct ground faults to the ground.
Explosionproof Equipment as per NEC
Explosionproof equipment is electrical equipment that is designed and constructed to contain an explosion that may occur within the equipment and to prevent the explosion from spreading to the surrounding environment. It is used in hazardous locations where there is a risk of explosion due to the presence of flammable gases, vapors, or dusts.
The National Electrical Code (NEC) includes provisions for the use and installation of explosionproof equipment in hazardous locations. These provisions include requirements for the construction and testing of the equipment, as well as requirements for the installation and protection of the equipment and the electrical conductors that serve it.
Explosionproof equipment is typically used in industrial and commercial settings, such as oil and gas processing plants, chemical plants, and grain elevators. It is an important safety feature that helps to prevent explosions and reduce the risk of injury and property damage.
Enclosure as per NEC
An enclosure, as defined by the National Electrical Code (NEC), is a cabinet, box, or other type of housing that is used to enclose electrical equipment or to protect electrical conductors from physical damage. Enclosures can be made of metal, plastic, or other materials, and they are designed to be weatherproof and mechanically sturdy.
The NEC includes provisions for the use and installation of enclosures in electrical systems, including requirements for the size and construction of the enclosure, the type of electrical equipment that can be installed in the enclosure, and the methods for attaching the enclosure to the electrical system.
Enclosures are an important part of an electrical system, as they help to protect electrical equipment and conductors from damage and provide a safe and secure location for making electrical connections. They also help to prevent electrical hazards by enclosing live electrical parts and keeping them out of reach of people.
Dwelling Unit as per NEC
A dwelling unit, as defined by the National Electrical Code (NEC), is a single unit of a building that is used as a housekeeping unit. It is a self-contained living space that is designed for the use of one or more persons and that includes permanent provisions for living, sleeping, eating, cooking, and sanitation.
The NEC includes specific requirements for the electrical installations in dwelling units, including requirements for the wiring methods, outlets, lighting, and appliances. These requirements are intended to ensure the safety and convenience of the occupants of the dwelling unit and to protect the dwelling unit from electrical hazards.
In addition to single-family homes, dwelling units can include apartments, condos, and other types of multi-family housing. The NEC includes provisions for the electrical installations in these types of dwelling units as well.
Demand Factor as per NEC
The demand factor is a factor that is used to adjust the electrical load of a system or circuit in order to account for the variations in the actual electrical demand that the system or circuit is likely to experience. It is typically expressed as a percentage, and it is used to ensure that the electrical system or circuit is designed to handle the maximum expected demand.
In the National Electrical Code (NEC), the demand factor is used in the calculations for determining the size of the conductors and the rating of the overcurrent protective devices for a given electrical system or circuit. The NEC includes tables that provide the demand factors for various types of electrical loads, such as lighting loads and appliance loads, based on the type of occupancy and the expected usage patterns.
The demand factor helps to ensure that the electrical system or circuit is properly sized to handle the expected load, and it helps to prevent overloading and reduce the risk of electrical fires.
Cutout Box as per NEC
A cutout box, also known as a cutout fuse or cutout switch, is a device that is used in an electrical distribution system to protect against overcurrents and short circuits. It consists of a fuse or circuit breaker mounted in a enclosure, which is connected to the electrical circuit through a pair of contacts.
When the current flowing through the circuit exceeds the rated capacity of the cutout box, the fuse or circuit breaker will open the circuit and interrupt the flow of electricity. This helps to prevent damage to the electrical system and reduce the risk of electrical fires.
Cutout boxes are typically installed at the point where the electrical service enters a building or at other strategic locations in the distribution system. They are used to protect the main service conductors, as well as the branch circuits that branch off from the main service.
Conduit Body as per NEC
A conduit body is a component of an electrical conduit system that is used to connect, terminate, or splice together electrical conduits. Conduit bodies are typically made of metal or plastic, and they are designed to be watertight and corrosion-resistant. They are used to provide access to the interior of the electrical conduit for the purpose of pulling wires or making connections.
Concealed as per NEC
The term “concealed” refers to something that is hidden or covered, so that it is not visible. In the context of electrical systems, a concealed conductor or device is one that is not visible and is not intended to be accessed or touched by people.
For example, a concealed conductor may be one that is run inside a wall or ceiling and is not accessible to people. A concealed device may be one that is mounted inside a box or enclosure and is not visible or accessible to people.
The NEC includes provisions for the installation and protection of concealed conductors and devices, as well as requirements for marking and identifying them in order to prevent accidental contact.
Branch Circuit as per NEC
A branch circuit is an electrical circuit that is used to distribute power from the main power source to the various outlets, fixtures, and other devices that are connected to it. Branch circuits are typically found in residential and commercial buildings, and they are used to provide power to specific areas or rooms within the building.
In the United States, branch circuits are typically required to be protected by a circuit breaker or fuse, which is designed to open the circuit in the event of an overcurrent or short circuit. The size of the branch circuit conductors and the type of circuit breaker or fuse that is used are typically determined based on the electrical load that the branch circuit will be required to carry.
The NEC includes specific requirements for the installation and protection of branch circuits, as well as provisions for determining the appropriate size of the branch circuit conductors based on the electrical load.
Bonding Jumper, System as per NEC
In an electrical system, a bonding jumper is a conductor that is used to establish an electrical connection between two or more conductive objects in order to ensure that they are at the same electrical potential. A bonding jumper is typically used to provide a low-resistance path for electrical currents that may be induced by external sources, such as lightning or power line surges.
The bonding jumper system is the overall system of bonding jumpers that is used to connect the different conductive elements of the electrical system. This includes the bonding jumpers themselves, as well as the other components that are used to connect the bonding jumpers to the conductive objects that they are bonding together.
The purpose of the bonding jumper system is to ensure that all metal parts of the electrical system are properly bonded together and at the same electrical potential. This helps to prevent electrical shock hazards and reduce the risk of electrical fires by ensuring that these metal parts are at the same potential as the grounding system.
Bonding Conductor or Jumper as per NEC
A bonding conductor, also known as a bonding jumper, is a conductor used to establish an electrical connection between two or more conductive objects in order to ensure that they are at the same electrical potential. Bonding conductors are typically used to provide a low-resistance path for electrical currents that may be induced by external sources, such as lightning or power line surges.
In electrical systems, bonding conductors are used to connect metal parts of the system that are not normally energized, such as metal conduit, metal enclosures, and metal structural elements. This helps to prevent electrical shock hazards and reduce the risk of electrical fires by ensuring that these metal parts are at the same potential as the grounding system.
Bonding conductors are also used in other types of systems, such as gas piping and plumbing systems, to ensure that the different conductive elements are properly bonded together.
Define Askarel as per NEC
Askarel is a type of insulating fluid that was commonly used in electrical equipment, such as transformers and circuit breakers, prior to the 1970s. It is a chlorinated aromatic hydrocarbon, and it was chosen for its excellent dielectric properties and fire resistance. However, askarel is also highly toxic and can be harmful to humans if it is ingested or comes into contact with the skin.
Due to the potential health and environmental risks associated with askarel, it has largely been replaced by other types of insulating fluids in modern electrical equipment. The use of askarel is now generally restricted to certain specialized applications where it is still considered the best choice for the required performance.
Ampacity Definition as per NEC
Ampacity is a term that refers to the amount of electrical current that a conductor or device can safely carry. The NEC includes tables that provide the allowable ampacities for different sizes and types of conductors, based on factors such as the conductor temperature rating, the type of insulation, and the ambient temperature. These tables are used to determine the appropriate size of conductor to use for a given electrical load.
It’s important to note that the ampacity of a conductor should not be exceeded, as doing so can cause the conductor to overheat and potentially result in a fire. The NEC includes requirements for the ampacity of conductors, as well as provisions for adjusting the ampacity of a conductor based on certain conditions, such as the number of conductors in a raceway or the ambient temperature.
Above topic is reference from International Electrical NEC and document is attached below for more knowledge.
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