GLOSSARY OF ELECTRICAL INDUSTRY TERMS
A CONCRETE RING – see concrete box. ADD-A-DEPTH RING – a means of extending CABLE – two or more insulated conductors the walls of a device box to the wall surface, wrapped in metal or plastic sheathing. CONCRETE-TIGHT FITTING – a fitting that, providing a barrier between a wiring device and CABLE BOX – a box provided with clamps to when assembled to conduit or tubing of the the surrounding wall material. accommodate either metallic or nonmetallic proper size, excludes concrete aggregate. sheathed cable. AIR PLENUM – a compartment or chamber to CONDUCTOR FILL – refers to the number of which one or more air ducts are connected and CABLE CLAMP – generic name for a clamp current carrying and grounding conductors which forms part of the air distribution system. that mechanically secures the cable to the permitted by the National Electrical Code electrical outlet box. (NEC) to be used in conduit and tubing. AMP (A) – a measurement of the amount of electrical current in a circuit at any moment. CANADIAN STANDARDS ASSOCIATION CONDUCTORS – electrical term describing (CSA) – an independent testing agency that wires capable of carrying an electrical current ARMOR – a metallic covering around the cable certifies products to its established standards of or wire being used as a ground, usually for mechanical protection. Typically interlocked safety and performance. sheathed with an insulating material. steel or aluminum. CARPET FLANGE – a ring that is used with a CONDUIT – (raceway) a pipe or tube designed ARMORED CABLE CLAMP – a means of floor box to provide a decorative finish. to enclose and protect conductors or cables securing armored cable to a box, providing an from moisture and physical damage. electrical ground. The clamp will accommodate CHASE NIPPLE – a term used for a threaded two cables. nipple. CONDUIT BODY – a portion of a conduit or tubing system that provides access through a CIRCUIT – the path of electrical flow from a removable cover(s) to the interior of the system B power source through an outlet and back to at a junction of two or more sections of the BX – see flexible armored cable. ground. system or at a terminal point of the system.
BAR HANGER – a means that is used to CLAMP BACK – a raceway fastening CONDUIT CLAMP – a fastening clamp used to position a lighting fixture or fan between ceiling accessory typically used with a conduit strap to mount raceways. joists or studs. The bar hanger may be position a raceway away from a wall. adjustable, and permits the electrical outlet box CONDUIT HANGER – a fastening means used to be positioned along its length. CLASS I locations – are those locations in to support conduit. which flammable gases or vapors are or may BEAM CLAMP – a fastening means, usually be present in the air in quantities sufficient to CONDULET – a term used to refer to malleable made of malleable iron or steel, commonly produce explosive or ignitable mixtures. or aluminum conduit bodies. used with hangers and a threaded rod to fasten a raceway to an I-beam. CLASS II locations – are those locations that CONNECTOR – a fitting intended to terminate are hazardous because of the present a cable or raceway into a box, panel, etc. BELL BOX – a Hubbell Inc. trade name for the combustible dust. BELL® brand of weatherproof boxes. CORD GRIP (CG) – a connector used to CLASS III locations – are those locations that terminate flexible cords and cables into an BLOCK-LOC ®– a Hubbell Inc. trade name for are hazardous because of the presence of enclosure. self-positioning masonry boxes and tile covers. easily ignitable fibers or flyings, but in which the fibers or flyings are not likely to be in COUPLING – a fitting intended to connect two BONDING – the permanent joining of metallic suspension in the air in quantities sufficient to lengths of raceway. parts to form an electrically conductive path produce ignitable mixtures. that will assure electrical continuity and the capacity to conduct safely any current likely to D CLEAT HANGER – see bar hanger. DAMP LOCATION – partially protected be imposed. locations such as under canopies or roofed CODEGUARD® – RACO trademark for open porches, and interior locations subject to BOX EXTENSION – see extension ring. weatherproof cover and Hubbell WRTR device. moderate degrees of moisture, such as basements, barns, and cold-storage BOX-LOC®– RACO trade name for our snap- COMBINATION COUPLING – a coupling on metal stud bracket. warehouses. device used to join two dissimilar raceways (ie., rigid and flex). BOX MOUNT – a term commonly used to DEVICE EARS – ears or tabs with holes spaced to accommodate wiring devices. Device denote where the screws of a cover attach. CONCENTRIC KNOCKOUT – a combination ears are found on plaster rings, switch boxes knockout where all the knockouts have the and handy boxes. BUSHING – a fitting provided to protect wires same center (eg., masonry boxes). from abrasion and intended for use where DEVICE MOUNT – a term commonly used to conductors enter or leave the raceway system. CONCRETE BOX – a box intended for use in denote where the screws of a device cover concrete and masonry block. It is not intended attach. C for installation in a floor. CSA – see Canadian Standards Association. GLOSSARY OF ELECTRICAL INDUSTRY TERMS
DUPLEX RECEPTACLE – Electrical outlet GORILLA-RING®– a RACO® concrete ring UL device having two plug receptacles. FINISHED WALLS – studs, furring strips, approved for fixture and ceiling fan support. joists, that are covered with wood paneling, DURALO® – is a trademark identifying a tri- drywall, plaster, Masonite or ceramic are GOTCHA – term for a split hinge design ring coat protective finish used on iron electrical considered finished. used in Hubbell strain relief cord connectors. conduit fittings for standard and hazardous locations. FIXTURE – a lighting assembly that is GREENFIELD – see flexible metal conduit. permanently attached to a building’s wiring E system, usually to a ceiling box. GRID-BRACE® – A Hubbell Inc. trade name for 8B – a 4 in. octagon box that is 1-1/2 in. deep. a ceiling support assembly designed for ceiling FIXTURE EARS – ears or tabs with holes in fan or fixture support for suspended ceilings. 8B DEEP – a 4 in. octagon box that is 2-1/8 in. them spaced 2- 3/4 in. or 3- 1/2 in. apart to deep. accommodate lighting fixtures. GRIP-LOK – refers to old work clips used to secure switch boxes with plaster ears in hollow ELBOW – a curved section of raceway FLEX – see flexible metal conduit. walls. intended to change the direction of the run. FLEXIBLE ARMORED CABLE (BX) – GROUND – a conducting connection between ELECTRICAL METALLIC TUBING (EMT OR commonly called BX, a manufacturer’s trade an electrical circuit or equipment and the earth, THINWALL) – conduit called thinwall as a name. It may be described as prewired flexible or to some conducting body that serves in contrast to the “heavywall” of rigid or IMC. metallic conduit since it includes two or more place of the earth. Neutral wires carry the current carrying conductors and can be current to ground in all circuits. An additional ELECTRICAL NONMETALLIC TUBING (ENT) supplied with a grounding conductor. grounding wire, or the sheathing of metal clad – a plastic corrugated raceway of circular cross cable or conduit, protects against shock from a section that is resistant to moisture and FLEXIBLE METAL CONDUIT (GREENFIELD malfunctioning tool or other device. chemical atmospheres, and that is flame OR FLEX) – frequently called “Greenfield,” retardant. which is the trade name of one manufacturer of GROUND FAULT CIRCUIT INTERRUPTER this flexible steel or aluminum raceway. It is (GFCI) – a safety device that senses shock ELECTROPLATING – a term used to describe used around machinery where vibration or hazard and automatically stops electrical flow in the process of electrically depositing a layer of movement exists or where complex routing of a circuit. corrosion resistant material (i.e., zinc) onto the raceway dictates a flexible conduit. steel or iron parts. GROUND FITTING – a fitting used to attach a FLOOR BOX – a box provided with means for grounding conductor to a ground pipe or rod. EMT – see electrical metallic tubing. flush mounting in a floor. The floor box may be used to provide power, telephone or data GROUND LUG – means used to connect a END RUN – that portion of the branch circuit connections in office or store areas. ground wire to a fitting, clamp, or enclosure. that extends to the last fixture or device. Generally made of copper, aluminum, brass or FLUSH-FIT® – a Hubbell Inc. trade name for a bronze. ERICKSN® COUPLING – a registered trade device leveling plate that corrects loose and name for a three-piece coupling used for recessed devices. GROUND SCREW – a UL listed screw used to rigid/IMC conduit. secure a grounding conductor to an enclosure. FORM 7 – a style of conduit body that requires ETL –certification mark for Intertek Testing a clip cover. GROUND WIRE – the conductor used to Services. ITS tests to the standards of UL, CSA connect the electrical equipment to ground (or and other international standards. FORM 8 – an “expanded volume” style of earth) at the service entrance point, minimizing conduit body that requires a two screw cover. the potential for electrical shock. Usually clad in EXPOSED WORK – boxes and branch circuits green insulation or unclad. that are mounted external or exposed on walls, FORM 35 – a style of conduit body that beams, columns, etc. requires a two screw cover. H HANDY BOX – box designed for enclosing EXTENSION RING – used to extend the box FURRING STRIPS – small wood strips devices; usually surface mounted. when it is recessed back in a wall. Also attached to an existing wall to provide a means provides more cubic inch capacity for the box if to attach paneling or drywall. HANDY ELL – a 90 degree elbow used either needed. to connect two runs of conduit, or to connect a G run of conduit to an enclosure. EXTRA DUTY® – a tradename applied to GFCI – see Ground Fault Circuit Interrupter. weatherproof while-in-use covers that have HAZARDOUS LOCATIONS – are those passed UL testing and are listed as “Extra GANGABLE – box with a side that can be locations where fire or explosion hazards may Duty”. removed to allow the attachment of another box exist due to flammable gases or vapors, for installation of multiple devices. flammable liquids, combustible dust, or F ignitable fibers or flyings. FAN BOX – a box that is UL listed for the GAUGE – a term used to describe the physical support of a ceiling (paddle) fan. size of a wire. HEAVYWALL – see rigid metal conduit.
GLOSSARY OF ELECTRICAL INDUSTRY TERMS
HICKEY – (1) a threaded extension for support KORNS® CLAMP – A registered trademark for of a lighting fixture. (2) conduit bending tool. a right angle, parallel, or edge type conduit MUD RING – all rings are called mud rings clamp, used to fasten conduit to I-beams. regardless of the finish wall material used. HIDDEN WORK – residential and commercial There are two styles of rings, one for mounting construction where the electrical work is hidden KWIK-BRACE® – a RACO® new work a switch or receptacle, and one for mounting by the finished wall; only the wiring device, adjustable brace that is UL approved for fixture lighting fixtures. switch, wall plate or light fixture is visible. and ceiling fan support. MYERS™ HUB – A trade name used to refer to HOT WIRE – the higher voltage conductor KWIK-HANG® – a RACO® swivel fixture cover a threaded hub for rigid/IMC conduit; provides a carrying electrical current (usually black) in a or box support hanger. threaded hub in a KO. 120V single phase system. L N I LAMPHOLDER – a current carrying device NEC – see National Electrical Code. I.D. – inside diameter. used to support, illuminate and protect lamps. NEMA – see National Electrical Manufacturer’s IMC – see intermediate metal conduit. LIQUIDTIGHT FLEXIBLE METAL CONDUIT – Association. flexible metal conduit with a plastic outer jacket INSULATED THROAT CONNECTORS – that protects the electrical system against NM – see nonmetallic sheathed cable. insulated throat connectors have a sunlight, liquids, vapors or solids. thermoplastic line pressed or glued into the NAIL-UP STRAPS – a fastening device used to throat. This liner helps to prevent damage to LIQUIDTIGHT FLEXIBLE NONMETALLIC mount raceways to wooden studs, siding, etc. the insulation when the conductors are pulled. CONDUIT (NMLT) – liquidtight flexible nonmetal conduit is a raceway of circular cross NATIONAL ELECTRICAL CODE (NEC) – a INSULATION – sheathing or jacket of section having a smooth inner surface with set of rules governing safe wiring methods nonconducting material used to cover wires. integral reinforcement within the conduit wall. drafted by the National Fire Protection Association. Local codes sometimes differ from INTERMEDIATE METAL CONDUIT (IMC) – LOAD BEARING – walls that are an integral and take precedence over NEC requirements. a lighter weight, more economical version of part of the structure that supports the joists. rigid metal conduit. It has the same outside NATIONAL ELECTRICAL diameter (O.D.) with a thinner wall. LOCKNUT – an internally threaded barbed nut MANUFACTURERS ASSOCIATION (NEMA) – for use on conduit or fittings to prevent turning a US Manufacturers Organization which J and to provide a secure joint. actively promotes standardized product JAKE FITTING – a commonly used term for a specifications for electrical apparatus. screw-in type connector or coupling for flexible LOW VOLTAGE PARTITION – a barrier added metal conduit. inside an electrical box to separate NEUTRAL WIRE – a grounded conductor that communication and power circuits. Also completes a circuit by providing a return path to JIFFY BOX – old work switch box. required where voltage levels between adjacent the source. Neutral wires are always identified switches exceed 300. by white or gray insulation. JOIST – horizontal beams that extend from wall to wall and support the floor or ceiling – LUG – see ground lug. NEW WORK – electrical work that is completed typically 2 in. x 10 in., 2 in. x 8 in. or 2 in. x 6 in. before the drywall or plaster is installed. M JUNCTION BOX – an enclosure used for MC CABLE – metal clad cable. A UL 1900 – a 4 in. square box that is 1-1/2 in. deep. splitting circuits into different branches. In a classification indicating an assembly of junction box, wires connect only to each other, insulated conductors with a metal cladding 1900 DEEP – a 4 in. square box that is 2-1/8 in. never to a switch, receptacle, or fixture. applied over the core and with grounding deep. conductor(s) if the cladding is interlocked K armor. NIPPLE – an externally threaded fitting intended primarily to serve as a short raceway KELLEMS GRIP – name for a wire mesh grip. between close-spaced enclosures. MADISON HOLD ITS® – Registered trademark for #977 griplok old work brackets. KILOWATT (KW) – one thousand watts, NONMETALLIC SHEATHED CABLE kilowatt measures power. MASONRY BOX – box installed in block walls (ROMEX®) – nonmetallic sheathed cable, popularly called by a manufacturer’s trade KILOWATT-HOUR – the standard measure of as the blocks are being laid. The mason cuts the block to fit around the box. name of Romex, is two or more insulated electrical consumption or energy. conductors, usually copper, protected by an
MOUNTING EARS – ears on a box which are outer jacket or sheath of nonmetallic material. KO (KNOCKOUT) – a circular tab on the side or bottom of a box pushed back in place with a used to mount a box cover, device or fixture. NMLT – see liquidtight flexible nonmetallic small piece of steel remaining uncut to hold the conduit. tab in place until it is removed for installation of MOUSE HOUSE – a metallic or nonmetallic pedestal that can provide power or voice/data conduit or a connector. to a floor location. GLOSSARY OF ELECTRICAL INDUSTRY TERMS
O RAFTER – parallel beams that support a roof ROMEX®– see nonmetallic sheathed cable. O.D. – outside diameter (of conduit, etc.). running from the top of the joist to the peak of the roof. S OCTAGON BOX – a metal box used on a SEAL-TITE® – A registered trademark used to wiring system, usually at an outlet. It provides RAINTIGHT – constructed so as to pass the UL refer to liquidtight metallic conduit and fittings. means for connection to a wiring system and is rain test. intended primarily to enclose splices and wiring SERVICE DROP – service entrance devices or to support a fixture or other RAYNGUARD® – RACO® trademark for extra conductors from the utility pole to the service equipment intended for similar installation. duty weatherproof proof metallic while in use entrance conductors of a building that has cover. overhead service. The utility company usually OFFSET CONNECTORS – connects the supplies and connects the service drop. conduit on the wall surface to a KO in the box RAYNTITE® – RACO® trademark for where the KO and wall surface are on different weatherproof device cover approved for use in SERVICE ENTRANCE – the point at which planes. wet locations. electrical service enters a building.
OLD WORK – electrical work that takes place RAISED COVER – used for a job that is SERVICE ENTRANCE CABLE (SE) – service after the drywall or plaster is in place. surface mounted. There are a variety of raised entrance cable can be compared to nonmetallic covers that may be used depending on the type sheathed cable (Romex®) in large conductor OUTLET – anything that allows access to the of device being installed. sizes, with a weatherproof nonmetallic outer wiring system (eg., box, conduit body, etc.). covering. It is often encased by rigid, IMC or REDI-LOC® – a registered RACO® trademark EMT conduit for additional protection. P for MCI, AC and HCF cable connectors. SERVICE-ENTRANCE HEAD – an enclosed PAN – see pancake box. RED SEAL COVER – see raised cover. fitting intended for use at service entrances where open wiring is connected to a service- PANCAKE BOX – this round box is also REDUCING BUSHING – a threaded steel or referred to as a pan. The pancake box typically entrance cable or raceway system. malleable iron bushing used to make transitions is the same depth as the finish wall material in from one trade size of rigid/IMC to another which it is mounted. SET BACK – the distance a box is set forward on a stud to accommodate the thickness of the REDUCING WASHER – a stamped steel finished wall and leave the face of the box flush PARTITION WALLS – walls that are nonload washer which, when used in pairs, reduces the bearing—typically interior walls of an office with the front surface of the wall. size of an opening in an enclosure. building that can be removed. SET SCREW CONNECTOR – a fitting which RETRO-BRACE® – a RACO® old work terminates a run of conduit into an enclosure PLASTER EARS – ears on switch boxes that adjustable brace for fixture or ceiling fan prevent the box from falling back into the wall. using set screws to secure the conduit. support.
PLASTER RING – see mud ring. SET-UP BOX – trade term for an octagon box, RETRO-RING® – a RACO® old work, steel factory installed on a bar hanger. mounting bracket for 4 in. square boxes. PLENUM – a compartment or chamber to which one or more air ducts are connected to SHEATH – material, usually an extruded plastic RIGID – see rigid metal conduit. material applied outermost to a wire or cable. form part of the air distribution system. Often called a jacket. RIGID METAL CONDUIT (RIGID OR PLUG – a threaded means used to close HEAVYWALL) – rigid metal conduit is a unused threaded openings. SHIELDED CABLE – a cable in which the raceway that provides a high degree of insulated conductor(s) are enclosed in a mechanical protection indoors or out, in dry or PREGALVANIZED – the application of hot zinc conductive mesh envelope. The mesh is wet locations, exposed or concealed, in all intended to protect the enclosed conductor(s) to the exterior surfaces of steel. kinds of atmospheric conditions, locations, and from external electrical interference. in hazardous locations such as explosion proof, PRIOUT – a circle or pear shaped tab cut into vapor tight and dust tight. the steel with a tie (a little piece of steel uncut) SPLICE – the joining of two or more conductors. holding it in place; the priout has a slot in it RIGID NONMETALLIC CONDUIT – three where a screwdriver tip is inserted to pry out types of rigid nonmetallic conduit are listed by SPLICE BOX – see junction box. the tab, providing an opening for cable. UL: (1) rigid nonmetallic plastic Schedule 40
and 80 PVC; (2) rigid nonmetallic underground SPLIT COUPLING – a term used to refer to a Q plastic; and (3) rigid nonmetallic underground coupling used for rigid/IMC conduit. Used QUICK-FIT – Keyhole mounting system. other than plastic, fiber type. where the conduits to be coupled cannot be rotated. R ROBERTSON HEAD SCREW – a type of RACE WAY – enclosed channel designed screw with a square key that is popular in STAB-IT® – a RACO® trademark for our line expressly for holding wire or cables. Conduit is Canada. A special tool (called a Robbie) is of boxes with built-in cable connectors for a raceway; so is a duct. required to drive the screw. flexible armored cable.
GLOSSARY OF ELECTRICAL INDUSTRY TERMS
STRAIN RELIEF – a term used to describe the sealing and gripping action of a cord connector. UL – see Underwriters Laboratories.
STRAPS – used to support conduit as required UNDERGROUND FEEDER CABLE – by Code. Beam and conduit clamps perform underground feeder cable (Type UF) is a group this function in industrial locations. of conductors manufactured in the form of a cable assembly similar to Type NM (Romex®) STUD – 2 in. x 4 in. or 2 in. x 6 in. wood or but with the physical and electrical steel used to construct walls. characteristics that allow for direct burial in the earth. STUD MOUNT – name for mud rings that allow for quick installation to studs and eliminates the UNDERWRITERS LABORATORIES (UL) – An needs for far-side support. independent testing agency that tests and lists electrical equipment to its established STUD WALL – wood or steel 2 in. x 4 in. standards of safety and performance. spaced 16 in. or 24 in. on center — drywall or paneling typically is attached to the studs to UTILITY BOX – see handy box. finish the wall. V SWITCH BOX – boxes with device ears for VOLT (v) – a unit of electromotive force. direct mounting of switches as opposed to boxes requiring mud rings for switch mounting. W WATT (w) – a measure of the power an SWIVEL LOK – reference for multi-position liquidtight connectors for type B liquidtight electrical device consumes; [volts x amps = flexible nonmetallic conduit and extra flexible watts]. liquidtight nonmetallic tubing. WEATHERHEAD – a term used to refer to a service entrance head. T THINWALL – see electrical metallic tubing. WEATHERPROOF – an enclosure constructed for outdoor use. TIGER BOX – name for a patented switch box for old work applications. WEATHERPROOF-WHILE-IN-USE (WEATHERPROOF-IN-USE, TILE COVER – a series of covers designed for WEATHERPROOF HOOD, OR OUTLET BOX use with tile. These covers are for mounting HOOD) – term commonly used to describe switches or receptacles. Rings are available in covers that are designed to be rain tight with different depths depending on the finished wall cords installed. thickness. WET LOCATIONS – installations underground TKO – references a combination 1/2 in. and 3/4 or in concrete slabs or masonry in direct in. knockout. The two knockouts are off-center contact with earth, and locations subject to to enable a 1/2 in. locknut to engage the box for saturation with water or other liquids, such as proper grounding of the electrical system. vehicle washing areas, and locations exposed to weather and unprotected. TOGGLE SWITCH – a switch intended for use in general distribution and branch circuits. WRTR – an electrical device that is weather- resistant and tamper-resistant. TOMBSTONE – see mouse house.
TRADE SIZE – conduit is referred to by trade size according to its inside diameter.
TYPE UF – see underground feeder cable.
U U·CONDUIT – A Hubbell trade name for the Universal Conduit Body. The U·Conduit Body’s interchangeable plates/panels allow the body to be configured into any of the five standard conduit body types LB, LL, LR, T, and C, for EMT or Rigid/IMC conduit.