Engineering Resources
Terms & Definitions
A Glossary of Commonly-used terms relevant to TLC Electronics products and services
APPLIANCE WIRE AND CABLE
A classification covering insulated wire and cable for internal wiring of appliances and equipment ARMOR — Mechanical protector for cables; usually a helical winding of metal tape, formed so that each convolution locks mechanically upon the previous one (interlocked armor); may be a formed metal tube or a helical wrap of wires.
AWG
American Wire Gauge. A wire diameter specification. The lower the AWG number the larger the wire diameter.
AWM
Appliance wiring material.
BARE CONDUCTOR
A conductor having no insulation or jacket BARREL
BELDFOIL®
Belden trademark for a highly effective electrostatic shield using reinforced metallic foil.
BINDER
A tape or thread used for holding assembled cable components in place.
BIRDCAGE
The undesired unwinding of a stranded cable.
BNC
Common connector for coax. BNC is said to be an abbreviation for Bayonet-Neill-Concelman.
BONDED CABLE
Cable consisting of preinsulated conductors or multiconductor components laid in parallel and bonded into a flat cable.
BONDED CONSTRUCTION
An insulation construction in which the glass braid and nylon jacket are bonded together.
BOOT
(1) Protective coating over a cable, wire or connector in addition to the normal jacketing or insulation. (2) A form placed around the wire termination of a multicontact connector to contain the liquid potting compound before it hardens.
BRAID
Textile or metallic filaments interwoven to form a tubular structure which may be applied over one or more wires or flattened to form a strap.
BREAKDOWN VOLTAGE
The voltage at which the insulation between two conductors breaks down.
BREAKOUT
The point at which a conductor or group of conductors breaks out from a multiconductor cable to complete circuits at various points along the main cable.
BUILDING WIRE
Commerical wires used in the building trades such as: Types RHH, RHW, THW, and THHN wire.
BURIED CABLE
A cable installed directly in the earth without use of underground conduit. Also called “direct burial cable.”
BUSHING
A mechanical device used as a lining for an opening to prevent abrasion to wire and cable.
BUTT SPLICE
A splice wherein two wires from opposite ends butt against each other, or against a stop, in the center of a splice.
C CONNECTOR
A bayonet-locking connector for coax; C is named after Carl Concelman.
CABLE
A cable may be a small number of large conductors or a large number of small conductors, cabled together, usually color coded and with a protective jacket overall.
CABLE ASSEMBLY
A cable assembly is a cable with plugs or connectors on each end for a specific purpose. It may be formed in various configurations.
CABLE CLAMP
A device used to give mechanical support to the wire bundle or cable at the rear of a plug or receptacle.
CABLE CORE
The portion of an insulated cable lying under a protective covering.
CABLE CORE BINDER
A wrapping of tapes or cords around the conductors of a multiple conductor cable used to hold them together.
CABLE FILLER
The material used in multiple conductor cables to occupy the interstices formed by the assembly of the insulated conductors, thus forming a cable core.
CABLE SHEATH
The protective covering applied to cables.
CABLE, TRAY
A multiconductor cable having a nonmetallic jacket, designed for use in cable trays per the National Electrical Code.
CABLING
The method by which a group of insulated conductors is mechanically assembled (or twisted together).
CAD
Computer-Aided Design.
CATV
Community antenna television. Refers to the use of a coaxial or fiber cable to transmit television or other signals to subscribers from a single head-end location.
CATV CABLE
General term for all cables used for community antenna TV service and feeders, distribution and house drops.
CCTV
Closed circuit television. One of the many services often found on broadband networks CCW — Continuously corrugated and welded. A type of cable sheath.
CIRCULAR MIL (CM)
A term universally used to define cross sectional areas of conductors. It is an area equal to the area of a circle 1/1000 of an inch in diameter. As the number of circular mils increase, the size of a wire increases.
COATED WIRE
Any metal covered by a relatively thin coating of a different metal such as tin, zinc or other alloy by a dip bath and wipe process, often at high speeds in line with insulating equipment.
COAXIAL CABLE
A cylindrical transmission line comprised of a conductor centered inside a metallic tube or shield, separated by a dielectric material, and usually covered by an insulating jacket.
COLOR CODE
A color system for wire or circuit identification by use of solid colors, tracers, braids, surface printing, etc.
COMPOSITE CABLE
A cable containing more than one gauge size or a variety of circuit types, e.g., pairs, triples, quads, coaxials, etc.
CONCENTRIC-LAY CONDUCTOR
A layer of uninsulated wires twisted around a central wire with subsequent layers spirally wrapped around the inner layers to form a single conductor.
CONDUCTANCE
The ability of a conductor to carry an electric charge. The ratio of the current flow to the potential difference causing the flow. The reciprocal of resistance.
CONDUCTIVITY
Capacity of a material to carry electrical current — usually expressed as a percentage of copper conductivity (copper being 100%).
CONDUCTOR CORE
The center strand or member about which one or more layers of wires or members are laid helically to form a concentric
CONDUCTOR SHIELD
A conducting layer applied to make the conductor a smooth surface in intimate contact with the insulation; sometimes called extruded strand shield (ESS).
CONNECTOR
A metallic device of suitable electric conductance and mechanical strength, used to splice the ends of two or more cable conductors, or as a terminal connector on a single conductor. Connectors usually fall into one of the following types:
CONTACT
The part of a connector which carries the electrical current.
CONTACT SIZE
The largest size wire which can be used with the specific contact. Also, the diameter of the engagement end of the pin.
CONTINUITY CHECK
A test performed on a length of finished wire or cable to determine if the electrical current flows continously throughout the length.
CONTROL CABLE
A cable used for remote control operation of any type of electrical power equipment.
CORD
A flexible insulated cable.
CORD SET
Portable cords fitted with a connector at one or both ends.
CORE
In cables, a component or assembly of components over which other materials are applied, such as additional components, shield, sheath, or armor.
COVERAGE
The calculated percentage which defines the completeness with which a metal braid covers the underlying surface. The higher percentage of coverage, the greater the protection against external interference.
CROSS TALK
A type of interference caused by audio frequencies from one circuit being coupled into an adjacent circuit. The term is loosely used to also include coupling at higher frequencies.
CROSS-LINKED
Inter-molecular bonds created between long chain thermoplastic polymers by chemical or electron bombardment means. The properties of the resulting thermosetting material are usually improved.
CROSS-LINKED POLYETHYLENE
A dielectric material used for insulating and jacketing. Also referred to as “XLP” or “XLPE.”
CSA (Canadian Standards Association)
Similar to UL in the United States.
DIELECTRIC
An insulating (nonconducting) medium.
DIELECTRIC BREAKDOWN
Any change in the properties of a dielectric that causes it to become conductive. Normally the failure of an insulation because of excessive voltage.
DIELECTRIC STRENGTH
The maximum voltage which an insulation can withstand without breaking down; usually expressed as a gradient in V/mil (volts per mil). Polyethylene for example has a dielectric strength of about 800 V/mil.
DIELECTRIC STRENGTH TESTING
A common test performed on electrical products which is often called hi-pot testing. A voltage higher than normal operating voltage is applied across the insulation. This test can increase product reliability by detecting faulty workmanship.
DIN
Deutsches Institut für Normung (DIN). The German Standard for many products.
DIRECT BURIAL CABLE
A cable installed directly in the earth.
DISTRIBUTION CABLE
(1) In a CATV system, the transmission cable from the distribution amplifier to the drop cable, (2) In an electric power system, provides low voltage service to the customer.
DRAIN WIRE
An uninsulated wire in contact with a shield throughout its length, used for terminating the shield.
DUCT
An underground or overhead tube for carrying electrical conductors.
DUOFOIL®
Belden trademark for a shield in which metallic foil is applied to both sides of a supporting plastic film.
DUPLEX CABLE
A cable composed of two insulated single conductor cables twisted together.
E
(1) Symbol for voltage. Usually used to represent direct voltage or the effective (root mean square) value of an alternating voltage, (2) A UL cable type. Elevator lighting and control cable.
ELASTOMER
Any material that will return to its original dimensions after being stretched or distorted.
ELECTRO-TINNED
Electrolytic process of tinning wire using pure tin.
ELECTROMOTIVE FORCE (E.M.F.)
Pressure or voltage. The force which causes current to flow in a circuit.
ELECTRONIC WIRE AND CABLE
Wire or cable used in electronic applications.
ELECTROSTATIC
Pertaining to static electricity, or electricity at rest. An electric charge, for example.
ELECTROSTATIC DISCHARGE
(ESD) An instantaneous flow of an electrical charge on a nonconductor through a conductor to ground.
ELONGATION
The fractional increase in the length of a material stressed in tension.
EMBOSSING
Identification by means of thermal indentation which leaves raised lettering on the sheath material of cable.
EMI
Electromagnetic Interference. External signals that disrupt the data being transmitted on the local area network or electronic device being operated. Typically, these external signals emanate from universal motors with brushes, fluorescent lights, personal computers, printers or other devices including copy machines, etc. The Federal Communications Commission (FCC) regulates this emission area.
ET
A UL cable type. Elevator lighting and control cable with thermoplastic insulation, three braids, flame retardant and moisture retardant finish. May have steel supporting strand in the center, 300 V.
ETCHED WIRE
A process applied to Teflon® wire in which the wire is passed through a sodium bath to create a rough surface to allow epoxy resin to bond to the Teflon®.
ETFE
Ethylene tetrafluoroethylene. Tefzel is DuPont’s trademark for this material.
EXPANDED DIAMETER
Diameter of shrink tubing as supplied. When heated the tubing will shrink to its extruded diameter.
EXTRUDED CABLE
Cable with conductors which are uniformly insulated and formed by applying a homogeneous insulation material in a continuous extrusion process.
EXTRUSION
A method of applying insulation to a conductor or jacketing to a cable. The process is continuous and utilizes rubber, neoprene or a variety of plastic compounds.
FEP
Fluorinated ethylene propylene. Teflon is DuPont’s trademark for this material.
FILLER
Fillers are used in multiconductor cables which occupy the interstices formed by the assembled conductors. This is done so that the finished cable will be round.
FINE STRANDED WIRE
Stranded wire with component strands of 36 AWG or smaller.
FLAME RESISTANCE
The ability of a material to not propagate flame once the heat source is removed.
FLAMMABILITY
The measure of a material’s ability to support combustion.
FLAT BRAID
A woven braid of tinned copper strands rolled flat at the time of manufacture to a specified width.
FLAT CABLE
A cable with two essentially flat surfaces.
FLEXIBLE
That quality of a cable or cable component which allows for bending under the influence of an outside force, as opposed to limpness which is bending due to the cable’s own weight.
FLUOROPOLYMER
A class of polymers used as insulating and jacketing materials. Common ones include Teflon, Tefzel, Kynar, and Halar.
FOIL
A thin, continuous sheet of metal.
GAUGE
A term used to denote the physical size of a wire.
GND
Ground.
GROUND
A voltage reference point that is the same as earth or chassis ground.
HARD-DRAWN WIRE
As applied to aluminum and copper, wire that has been cold drawn to final size so as to approach the maximum strength attainable.
HARNESS
An arrangement of wires and cables, usually with many breakouts, which have been tied together or pulled into a rubber or plastic sheath, used to interconnect an electric circuit.
HEATER CORD
A group of cable types defined in Article 400 of the NEC.
HELICAL STRIPE
A continuous, colored, spiral stripe applied to a conductor for circuit identification.
HELIX
Spiral winding.
HIGH TEMPERATURE WIRE AND CABLE
Electrical wire and cables having thermal operating characteristics of 150°C and higher.
HIGH TENSION CABLES
Generally the high voltage ignition wires for combustion engines, gas and oil ignitors, or neon signs, etc. (Unshielded.) Usually Type GTO.
HIPOT
A DC high potential test used on medium and high voltage cables.
HOLDING STRENGTH
Ability of a connector to remain assembled to a cable when under tension.
HOOKUP WIRE
Small wires used to hook up instruments or electrical parts, usually 12 AWG and smaller.
HOT STAMPING
Method of alphanumeric coding. Identification markings are made by pressing heated tape and marking foil into softened insulation surfaces.
HOT TIN DIP
A process of passing bare wire through a bath of molten tin to provide a coating.
HOUSING
A metallic or other enclosure for an insulated splice.
HPD
A UL cable type. Two, three or four conductor heater cord with thermoset insulation and cotton or rayon outer covering. For use in dry locations.
HPN
A UL cable type. Two or three conductor, thermosetting insulated heater cord. Parallel construction. For use in damp locations.
HSO
A UL cable type. Thermoset jacketed heater cord.
HV
High Voltage.
HYPOT®
(see hipot) Registered trade name of Associated Research, Inc. for their high-voltage tester.
I
Symbol used to designate current.
IEEE
Institute of Electrical and Electronic Engineers. An international professional society that issues its own standards and is a member of ANSI and ISO.
IMPEDANCE
The total opposition a circuit, cable, or component offers to alternating current. It includes both resistance and reactance and is generally expressed in ohms.
IMPEDANCE MATCH
A condition whereby the impedance of a particular cable or component is the same as the impedance of the circuit, cable, or device to which it is connected.
IMPEDANCE, HIGH
Generally, the area of 25,000 ohms or higher.
IMPEDANCE, LOW
Generally, the area of 1 through 600 ohms.
INPUT
(1) A signal (or power) which is applied to a piece of electric apparatus, (2) The terminals on the apparatus to which a signal or power is applied.
INSERTION TOOL
A small, hand-held tool used to insert contacts into a connector.
INSULATED SPLICE
A splice with a dielectric medium applied over the connected conductors and adjacent cable insulation.
INSULATION
A material having good dielectric properties which is used to separate close electrical components, such as cable conductors and circuit components.
INSULATION TEMPERATURE RATING
A maximum temperature assigned to insulations based on laboratory tests.
INSULATION THICKNESS
The wall thickness of the applied insulation.
INTERAXIAL SPACING
Center-to-center conductor spacing in paired wire or center-to-center spacing between conductors in a flat cable.
INTERCONNECTION
Mechanically joining devices together to complete an electrical circuit.
INTERNAL WIRING
Electronic wiring which interconnects components, usually within a sealed subsystem.
IRRADIATION
In insulations, the exposure of the material to high energy emissions for the purpose of favorably altering the molecular structure.
ISO 9000
A set of quality standards widely used around the world.
JACKET
Pertaining to wire and cable, the outer sheath which protects against the environment and may also provide additional insulation.
JOINT
That portion of the conductor where the ends of two wires, rods, or groups of wires are joined by brazing, soldering, welding or by mechanical means.
KAPTON
DuPont’s trademark for polyimide.
kV
Kilovolt (1,000 volts).
KYNAR
Atochem trademark for polyvinylidene fluoride (PVDF).
LAY
Pertaining to wire and cable, the axial distance required for one cabled conductor or conductor strand to complete one revolution about the axis around which it is cabled.
LAY DIRECTION
The twist in the cable as indicated by the top strands while looking along the axis of the cable away from the observer. Described as “right hand” or “left hand.”
LEAD
A wire, with or without terminals, that connects two points in a circuit.
LED
Light Emiting Diode; device that accepts electrical signals and converts the energy to a light signal; with lasers, the main light source for optical fiber transmission, used mainly with multimode fiber.
LIMPNESS
The ability of a cable to lay flat or conform to a surface.
LITZ WIRE
Very fine, usually #44 bare copper, each strand is enamel insulated and nylon wrapped (formerly silk). Used for low inductance coil windings.
LONGITUDINAL SHIELD
A tape shield, flat or corrugated, applied longitudinally with the axis of the cable.
LONGITUDINAL SHRINKAGE
A term generally applied to shrink products denoting the axial length lost through heating in order to obtain the recovered diameter.
LONGITUDINAL WRAP
Tape applied longitudinally with the axis of the core being covered.
LOW LOSS DIELECTRIC
An insulating material that has a relatively low dielectric loss, such as polyethylene or Teflon.
LOW NOISE CABLE
A cable specially constructed to eliminate spurious electrical disturbances caused by capacitance changes or self generated noise induced by either physical movement or adjacent circuitry.
LOW VOLTAGE
(1) As defined in the National Electrical Code, a system rated nominal 24 volts or less, supplied from a transformer, converter, or battery, (2) A power system voltage rating of 1,000 Volts or less.
MAGNET WIRE
Insulated wire used in the windings of motors, transformers, and other electromagnetic devices.
MARKER TAPE
A tape laid parallel to the conductors under the sheath in a cable, imprinted with the manufacturer’s name and the specification to which the cable is made.
MARKER THREAD
A colored thread laid parallel and adjacent to the strand in an insulated conductor which identifies the manufacturer and sometimes the specification to which the wire is made.
MASTIC
A meltable coating used on the inside of some shrink products which when heated flows to help create a waterproof seal.
MFT
Abbreviation for 1,000 feet.
MG
Glass reinforced mica tape insulated cable with an overall sheath of woven glass yarn impregnated with a flame, heat and moisture resistant finish. 450°C, 600 V appliance wire.
MICROPHONE CABLE
A very flexible, usually shielded cable used for audio signals.
mil
A unit of length equal to one thousandth of an inch.
MIL-C-17
A military specification covering many coaxial cables
MIL-W-16878
A military specification covering various wires intended for internal wiring of electric and electronic equipment.
MIL-W-22759
A military specification for fluorocarbon insulated copper and copper alloy wire.
MOISTURE RESISTANCE
The ability of a material to resist absorbing moisture from the air or when immersed in water.
MOLDED PLUG
A connector molded on either end of a cord or cable.
MOTOR LEAD WIRE
Wire which connects to the fragile magnet wire found in coils, transformers, and stator or field windings.
MTW
Machine tool wire. Thermoplastic insulated, 90°C to 105°C, 600 V. A UL cable type.
MULTIPLE-CONDUCTOR CONCENTRIC-CABLE
An insulated central conductor with one or more tubular stranded conductors laid over it concentrically and insulated from one another.
MULTIPLE-CONDUCTOR-CABLE
A combination of two or more conductors cabled together and insulated from one another and from sheath or armor where used.
mV
Millivolt (one thousandth of a volt.)
MYLAR
DuPont’s trademark for polyethylene terephthalate (polyester) film.
N CONNECTOR
A threaded connector for coax; N is named after Paul Neill.
N-SERIES CONNECTOR
A coaxial connector (RG-8/U) used in standard Ethernet networks.
NEC
National Electrical Code.
NEOPRENE
A synthetic rubber with good resistance to oil, chemicals, and flame. Also called polychloroprene.
NICKEL CLAD COPPER WIRE
A wire with a layer of nickel on a copper core where the area of the nickel is approximately 30% of the conductor area.
NM
A UL cable type. Nonmetallic sheathed cable, braid or plastic covered. For dry use, 90°C conductor rating.
NM-B
A UL cable type.
NMC
Nonmetallic sheathed cable, plastic or neoprene covered. Wet or dry use, 90°C conductor rating.
NOISE
In a cable or circuit any extraneous sounds or signal which tends to interfere with the sound or signal normally present in or passing through the system.
NOMEX
DuPont’s trademark for a heat resistant, flame retardant nylon.
NOMINAL
Name or identifying value of a measurable property by which a conductor or component or property of a conductor is identified, and to which tolerances are applied.
NOMINAL VOLTAGE (NATIONAL ELECTRICAL CODE)
A nominal value assigned to a circuit or system for the purpose of conveniently designating its voltage class (as 120/240, 480Y/277, 600 etc.). The actual voltage at which a circuit operates can vary from the nominal within a range that permits satisfactory operation of equipment.
NONCONTAMINATING
A type of PVC jacket material whose plasticizer will not migrate into the dielectric of a coaxial cable and thus avoid contaminating and destroying the dielectric.
NONFLAMMABLE
The property of a material that is not capable of being easily ignited.
NYLON
An abrasion-resistant thermoplastic with good chemical resistance.
OD
Outside diameter.
OEM
Original equipment manufacturer.
OHM
The electrical unit of resistance. The value of resistance through which a potential difference of one volt will maintain a current of one ampere.
OPEN CIRCUIT
A break in an electrical circuit so that there can be no current flow.
OPTICAL ENCODER
A device whose position is determined by a photoelectric device and converted to an electrical data output.
OPTICAL FIBER
Any filament or fiber, made of dielectric materials, that is used to transmit light signals; optical fiber usually consists of a core, which carries the signal, and cladding, a substance with a slightly higher refractive index than the core, which surrounds the core and serves to reflect the light signal.
OUTDOOR TERMINATION
A cable termination intended for use where it is not protected from direct exposure to either solar radiation or precipitation.
OUTGASSING
Dissipation of gas from a material.
OUTPUT
The useful power or signal delivered by a circuit or device.
OVERALL DIAMETER
Finished diameter over wire or cable.
OVERCOAT CONDUCTOR
A stranded conductor made from individual strands of tin-coated wire stranded together, and then given an overall tin coat.
OVERLAP
The amount the trailing edge laps over the leading edge of a spiral tape wrap.
PAIR
Two insulated wires of a single circuit associated together; also known as a “balanced” transmission line.
PARALLEL CIRCUIT
A circuit in which identical voltage is presented to all components, and the current divides among the components according to the resistances or the impedances of the components.
PARALLEL STRIPE
A stripe applied longitudinally on a wire or cable parallel to the axis of the conductor.
PATCH CABLE
A cable with plugs or terminals on each end of the conductors to temporarily connect circuits of equipment together.
PCB
Printed Circuit Board.
PE
Polyethylene. A widely used thermoplastic insulation and jacket compound.
PEAK
The maximum instantaneous value of a varying current or voltage. Also called crest.
PICO
Prefix meaning one-millionth of one-millionth of one millionth (10-12).
PIGTAIL WIRE
Fine stranded, extra flexible, rope lay lead wire attached to a shield for terminating purposes.
PITCH
In flat cable, the nominal distance between the index edges of two adjacent conductors.
PLASTICIZER
A chemical added to plastics to make them softer and more flexible.
PLENUM
The air return path of a central air handling system, either ductwork or open space over a suspended ceiling.
PLENUM CABLE
Cable approved by a recognized agency such as UL for installation in plenums without the need for conduit.
PLTC
Power Limited Tray Cable, rated 300 volts.
PLUG
The part of the two mating halves of a connector which is movable when not fastened to the other mating half.
POINT-TO-POINT WIRING
An interconnecting technique wherein the connections between components are made by wires routed between connecting points.
POLARIZATION
The orientation of a flat cable or a rectangular connector.
POLYESTER
Polyethylene terephthalate, used extensively as a moisture resistant cable core wrap. Mylar is DuPont’s trademark for polyester.
POLYETHYLENE
A thermoplastic material having excellent electrical properties.
POLYIMIDE
A relatively high temperature plastic developed for use as a dielectric or jacketing material. Kapton is DuPont’s trademark for polyimide.
POLYMER
A substance made of many repeating chemical units or molecules. The term polymer is often used in place of plastic, rubber, or elastomer.
POLYOLEFINS
A family of plastics including cross-linked polyethylene and various ethylene copolymers.
POLYPROPYLENE
A thermoplastic similar to polyethylene but stiffer and having a higher temperature softening point.
POLYURETHANE
Broad class of polymers noted for good abrasion and solvent resistance. Can be in solid or cellular form.
POLYVINYL CHLORIDE (PVC)
A general purpose thermoplastic used for wire and cable insulations and jackets.
POSJ
All rubber, parallel, light duty ripcord for use on lamps and small appliances, 300 V, 60°C.
POTTING
Sealing by filling with a substance to exclude moisture.
POWER CABLES
Cables of various sizes, constructions, and insulations, single or multiconductor, designed to distribute primary power to various types of equipment.
POWER LOSS
The difference between the total power delivered to a circuit, cable, or device, and power delivered by that device to a load.
PPE
Polypropylene ethylene.
PRIMARY INSULATION
The first layer of nonconductive material applied over a conductor, whose prime function is to act as electrical insulation.
PRINTING WIRING
A printed circuit intended to provide point-to-point electrical connections.
PRODUCTION TESTS
Tests made on components or subassemblies during production for the purpose of quality control.
PROTECTIVE COVERING
A field-applied material to provide environmental protection over a splice or housing, or both.
PT
Thermostat cable with solid conductor, individual insulation, twisted together.
PTFE
Polytetrafluoroethylene. One type of Teflon. Sometimes abbreviated TFE.
PULLING EYE
A device used to pull cable into or from a duct.
PULSE
A current or voltage which changes abruptly from one value to another and back to the original value in a finite length of time.
PVC
Polyvinyl chloride. A common insulating and jacketing material used on cables.
PVC-I-A
A MIL-C-17 coax jacket type. A black polyvinyl chloride with excellent weathering and abrasion properties, but is a contaminating type and will cause cable attenuation to increase with age. Can be used for direct burial.
PVC-II-A
A MIL-C-17 17 coax jacket.
PVDF
Polyvinylidene fluoride. Atochem’s trademark for this material is Kynar.
QUAD
A series of four separately insulated conductors, generally twisted together in pairs.
RECOVERED DIAMETER
Diameter of shrinkable products after heating has caused it to return to its extruded diameter.
REEL
A revolving flanged device made of wood or metal, used for winding flexible cable.
REFLOW SOLDERING
The process of connecting two solder-coated conductive surfaces by remelting of the solder to cause fusion.
REINFORCED SHEATH
The outer covering of a cable which has a reinforcing material, usually a braided fiber, molded in place between layers.
RESIN
A solid or semisolid organic substance, originally of plant origin but largely synthesized now. Resins are broadly classified as thermoplastic or thermosetting according to whether they soften or harden with the application of heat.
RESISTANCE
In DC circuits, the opposition a material offers to current, measured in ohms. In AC circuits, resistance is the real component of impedance, and may be higher than the value measured at DC.
RETRACTILE CORD
A cord having specially treated insulation or jacket so that it will retract like a spring. Retractability may be added to all or part of a cord’s length.
RETURN WIRE
A ground wire or the negative wire in a direct-current circuit.
RG/U
“RG” is the military designation for coaxial cable, and “U” stands for “general utility.”
RHH
Rubber-insulated, heat-resistant building wire, 90°C. A UL cable type.
RHW
Rubber-insulated building wire, heat and moisture-resistant, 75°C dry or wet. A UL cable type.
RHW-2
Rubber-insulated building wire, heat and moisture-resistant, 90°C dry or wet. A UL cable type.
RIBBON CABLE
A flat cable of individually insulated conductors lying parallel and held together by means of adhesive or woven textile yarn.
RIDGE MARKER
One or more ridges running laterally along the outer surface of a plastic insulated wire for purposes of identification.
RIGID COAXIAL CABLE
Nonflexible coaxial cable, usually a metal tube armored coaxial cable. Sometimes called “hardline.”
RING TONGUE
A solderless terminal that connects wire to a stud.
RIP CORD
Two or more insulated conductors in a parallel configuration which may be separated to leave the insulation of each conductor intact.
RMS
See Root-Mean-Square. The effective value of an alternating current or voltages.
ROMEX
A type of nonmetallic sheathed cable.
ROPE CONCENTRIC
A group of stranded conductors assembled in a concentric manner.
ROUND CONDUCTOR FLAT CABLE
A cable made with parallel round conductors in the same plane.
ROUND WIRE SHIELDS
Shields constructed from bare, tinned, or silver-plated copper wire that include braided, spiral, and reverse spiral.
RS-232
An EIA recommended standard (RS); a common standard for connecting data processing devices. RS-232 defines the electrical characteristics of the signals in the cable that connect DTE with DCE; it specifies a 25-pin connector (the DB-25 connector is almost universally used in RS-232 applications); and it is functionally identical to CCITT V.24/V.28.
RS-232-C
A technical specification published by the EIA that specifies the mechanical and electrical characteristics of the interface for connecting DTE and DCE. It defines interface circuit functions and their corresponding connector pin assignments. The standard applies to both asynchronous and synchronous serial, binary data transmission at speeds up to 20 Kbps in full-or half-duplex mode. RS-232-C defines 20 specific functions. The physical connection between DTE and DCE is made through plug-in, 25-pin connectors. RS-232-C is functionally compatible with the CCITT Recommendation V.24.
RS-422
A standard operating in conjuction with RS-449 that specifies electrical characteristics for balanced circuits. An EIA recommended standard for cable lengths that exceed the RS-232 50-foot limit. Although introduced as a companion standard with RS-449, RS-422 is most frequently implemented on unused pins of DB-25 (RS-232) connectors. Electrically compatible with CCITT recommendation V.11.
RUBBER INSULATION
A general term used to describe wire insulations made of elastomers such as natural or synthetic rubbers, neoprene, Hypalon, EPR, CPE, and others.
RUBBER, ETHYLENE PROPYLENE (EPR)
A synthetic rubber insulation having excellent electrical properties.
RULAN
DuPont’s trade name for their flame-retardant polyethylene insulating material.
S
A UL cable type. Hard service flexible cord with thermoset insulation and jacket.
S/N
See Signal-to-Noise Ratio.
SAE
Society of Automotive Engineers.
SECONDARY INSULATION
A nonconductive material that protects the conductor against abrasion and provides a second barrier.
SELF-EXTINGUISHING
Characteristic of a material whose flame is extinguished after the igniting flame source is removed.
SEMIRIGID CABLE
Generally refers to Type MI or Type ALS which can be bent or shaped into a required configuration from coils or reels.
SEMIRIGID PVC
A hard semiflexible polyvinylchoride compound with low plasticizer content.
SEPARATOR
Pertaining to wire and cable, a layer of insulating material such as textile, paper, Mylar, etc., which is placed between a conductor and its dielectric, between a cable jacket and the components it covers, or between various components of a multiple conductor cable. It can be utilized to improve stripping qualities and/or flexibility, or can offer additional mechanical or electrical protection to the components it separates.
SERIES CIRCUIT
A circuit in which the components are arranged end to end to form a single path for current.
SERVED WIRE ARMOR
Spiral wrap of soft galvanized steel wires wrapped around a cable to afford mechanical protection and increase the cable-pulling tension characteristic.
SEU
A UL cable type. Service Entrance Underground Cable, 600 volts.
SEW, SEWF
A CSA cable type. Silicone rubber-insulated equipment wire.
SF
A CSA cable type. Silicone rubber insulated fixture wire, solid or 7 strand conductor, 200°C.
SFF
A CSA cable type. Same as SF, except flexible stranding 150°C.
SG
A CSA cable type. Same as SW except with ground wires.
SGO
A CSA cable type. Same as SWO except with ground wires.
SHEATH
The outer covering or jacket over the insulated conductors to provide mechanical protection for the conductors.
SHIELD
A sheet, screen, or braid of metal, usually copper, aluminum, or other conducting material placed around or between electric circuits or cables or their components, to contain any unwanted radiation, or to keep out any unwanted interference.
SHIELD PERCENTAGE
The physical area of a circuit or cable actually covered by shielding material, expressed in percent.
SHIELDED INSULATED SPLICE
An insulated splice in which a conducting material is employed over the full length of the insulation for electric stress control.
SHORT
A low resistance path that results in excessive current flow and often in damage.
SHRINK TEMPERATURE
That temperature which effects complete recovery of a heat shrinkable product from the expanded state.
SHRINK TUBING
Tubing which has been extruded, crosslinked, and mechanically expanded which when reheated or released will return to its original diameter.
SHRINKING RATIO
The ratio between the expanded diameter and recovered diameter of shrinkable products.
SHUNT WIRE
A conductor joining two parts of an electric circuit to divert part of the current.
SIGNAL CABLE
A cable designed to carry current of usually less than one ampere per conductor.
SIGNAL-TO-NOISE RATIO
A ratio of the amplitude in a desired signal to the amplitude of noise, usually expressed in db.
SILICONE
A material made from silicon and oxygen. Can be in thermosetting elastomer or liquid form. The thermosetting elastomer form is noted for high heat resistance.
SJ
A UL cable type. Junior hard service, rubber-insulated pendant or portable cord. Same construction as type S, but 300 V.
SJO
Same as SJ, but with oil-resistant jacket.
SJOO
Same as SJO but with oil-resistant insulation as well as an oil-resistant jacket.
SJT
A UL cable type. Junior hard service thermoplastic or rubber insulated conductors with overall thermoplastic jacket. 300 V.
SJTO
Same as SJT but oil-resistant thermoplastic outer jacket.
SJTOO
Same as SJTO but with oil-resistant insulation.
SO
A UL cable type. Hard service cord, same construction as type S except oil-resistant thermoset jacket, 600 V.
SOFT WIRE
Wire that has been drawn or rolled to final size and then heated (annealed) to remove the effects of cold working.
SOLID CONDUCTOR
A conductor consisting of a single wire.
SOO
Same as SO but with oil-resistant insulation.
SOOW-A
A UL cable type. Portable cord and control cable. 600 V. Same as SOO but UL Listed for outdoor use.
SOW
A CSA cable type. A water-resistant thermoset-jacketed portable cord approved for outdoor use.
SP-1
A UL cable type. All thermoset, parallel-jacketed, two-conductor light duty cord for pendant or portable use in damp locations, 300 V.
SP-2
Same as SP-1, but heavier construction, with or without third conductor for gounding purposes, 300 V.
SP-3
Same as SP-2, but heavier construction for refrigerators or room air-conditioners, 300 V.
SPAN
In flat conductors, distance between the reference edge of the first and the last conductor. In round conductors, distance between centers of the first and last conductors.
SPIRAL SHIELD
A metallic shield of fine stranded wires applied spirally rather than braided.
SPIRAL STRIPE
A color coding stripe applied helically to the surface of an insulated wire or cable.
SPIRAL WRAP
The helical wrap of a tape or thread over a core.
SPLICE
A connection of two or more conductors or cables to provide good mechanical strength as well as good electrical conductivity.
SPT
A UL type of thermoplastic-insulated, 2 or 3 conductor parallel cord. Frequently called “Zip cord” or “Lamp cord.”
SR
Silicone rubber cable 600 V, 125°C.
ST
A UL cable type. Hard service cord, jacketed, same as type S except thermoplastic construction. 600 V, 60°C to 105°C.
STANDARD
A set of rules or protocols that describe how a device should be manufactured so it will be reliable and interoperability (compatibility) with others of the same type from different manufacturers will be maintained.
STATIC CHARGE
An electrical charge that is bound to an object. An unmoving electrical charge.
STIFFNESS
As applied to copper, the property of a conductor that causes it to resist permanent deformation by bending.
STO
Same as ST but with oil-resistant thermoplastic outer jacket, 600 V, 60°C.
STOO
Same as STO but with oil-resistant insulation.
STP
Shielded Twisted Pair. Two wires, wound around each other to help cancel out any induced noise in balanced circuits. Multiple pairs of wires are contained in one sheath, and each wire pair is shielded.
STRAND
One of the wires of any stranded conductor.
STRANDED CONDUCTOR
A conductor composed of a group of wires, usually twisted, or of any combination of such groups of wires.
STRIP
To remove insulation from a wire or cable.
SUGGESTED WORKING VOLTAGE
AC voltage that can be applied between adjacent conductors.
SURGE
A temporary and relatively large increase in the voltage or current in an electric circuit or cable. Also called transient.
SV
A UL cable type. Vacuum cleaner cord, two or three conductor, rubber insulated. Overall rubber jacket. For light duty in damp locations, 300 V 60°C.
SVO
A UL cable type. Same as SV except oil-resistant thermoset jacket, 300 V 60°C or 90°C.
SVT
A UL cable type. Same as SV except thermoplastic jacket. 300 V, 60°C or 90°C.
SVTO
A UL cable type. Same as SVT, except with oil-resistant thermoplastic jacket, 60°C.
T
Thermoplastic vinyl, building wire, 60°C.
TAKE-UP
The process of accumulating wire or cable onto a reel, bobbin, or some other type of pack. Also, the device for pulling wire or cable through a piece of equipment or machine.
TAPE WRAP
A spirally applied tape over an insulated or uninsulated wire.
TAPED INSULATION
Insulation of helically wound tapes applied over a conductor or over an assembled group of insulated conductors.
TAPED SPLICE
A joint with hand-applied tape insulation.
TC
A UL cable type. See Tray Cable, NEC Art. 340.
TEFLON
Trademark of the DuPont Co. for FEP, PTFE, and PFA polymers.
TEMPERATURE RATING
The maximum temperature at which an insulating material may be used in continuous operation without loss of its basic properties.
TERMINALS
Metal wire termination devices designed to handle one or more conductors, and to be attached to a board, bus or block with mechanical fasteners or clipped on.
TEST LEAD
A flexible, insulated lead wire used for making tests, connecting instruments to a circuit temporarily, or for making temporary electrical connections.
TEW
Canadian Standards Association type appliance wires. Solid or stranded single conductor, plastic insulated, 105°C, 600 V.
TF
A UL cable type. Fixture wire, thermoplastic-covered solid or 7 strands, 60°C.
TFE
One of three types of Teflon. Also known as PTFE (polytetrafluoroethylene).
TFF
Same as TF but flexible stranding, 60°C.
TFFN
Same as TFF but with nylon outer jacket.
TFN
Same as TF but with nylon outer jacket.
TG
Flexible nickel or nickel-clad copper conductor, Teflon tape, glass braid, 200°C.
THERMOCOUPLE
A device consisting of two dissimilar metals in physical contact, which when heated will develop an emf output.
THERMOCOUPLE ELEMENT
A thermocouple designed to be used as part of an assembly, but without associated parts such as terminal block, connecting head, or protecting tube.
THERMOPLASTIC
A material which softens when heated and becomes firm on cooling.
THHN
A UL cable type. 600 V, 90°C nylon-jacketed building wire.
THW
A UL cable type. Thermoplastic vinyl-insulated building wire. Flame-retardant, moisture and heat resistant. 75°C Dry and wet locations.
THWN
A UL cable type. Same as THW but with nylon jacket overall. Rated 75°C wet and 90°C dry.
TIN OVERCOAT (TOC)
Tinned copper wire, stranded, then coated with pure tin.
TNC
A threaded connector for miniature coax; TNC is said to be an abbreviation for threaded-Neill-Concelman. Contrast with BNC.
TOPCOAT
Bare (untinned) copper wire, stranded then coated with pure tin.
TPE
Thermoplastic Elastomer.
TRACER
A means of identifying polarity.
TRANSITION SPLICE
A cable splice which connects two different types of cable.
TRAY
A cable tray system is an assembly of units or sections, and ancillary fittings, made of noncombustible materials used to support cables. Cable tray systems include ladders, troughs, channels, solid bottom trays, and similar structures.
TRAY CABLE
A factory-assembled multiconductor or multipair control cable approved under the National Electrical Code for installation in trays.
TRIAXIAL
A three conductor cable with one conductor in the center, a second circular conductor concentric with and insulated from the first, and a third circular conductor insulated from and concentric with the second, and an impervious sheath overall.
TRUE CONCENTRIC
A cable conductor in which each successive layer has a reversed direction of lay from the preceding layer.
TUBING
A tube of extruded nonsupported plastic material.
TURNKEY SYSTEM
Any system that is completely assembled and tested and that will be completely operational by turning it “on.”
TV CAMERA CABLE
Multiconductor (often composite) to carry power for camera, lights, maneuvering motors, intercom signals to operators, video, etc. Usually heavy duty jacketed.
TW
A UL cable type. Thermoplastic vinyl-jacketed building wire, moisture resistant 60°C.
TWIN CABLE
A pair of insulated conductors twisted, sheathed, or held together mechanically and not identifiable from each other in a common covering.
TWIN COAXIAL
A configuration containing two separate, complete coaxial cables laid parallel or twisted around each other in one unit.
TWINAXIAL CABLE
A shielded coaxial cable with two central insulated conductors.
TWINNER
A device for twisting together two conductors.
TWISTED PAIR
A pair of insulated copper conductors that are twisted around each other, mainly to cancel the effects of electrical noise; typical of telephone and LAN wiring.
UF
A UL cable type. Thermoplastic underground feeder or branch circuit cable.
UL
Underwriters’ Laboratories, Inc.
UL LISTED
A product that has been tested and found to comply with Underwriters Laboratories’ standards.
UTP
Unshielded Twisted Pair. Two wires, usually twisted around each other to help cancel out any induced noise in balanced circuits. An unshielded twisted pair cable usually contains four pairs of wire in a single cable jacket.
V
Volts. The SI unit of electrical potential difference. One volt is the difference in potential between two points of a conducting wire carrying a constant current of one ampere when the power dissipated between these two points is equal to one watt.
VG
Varnished-glass or nylon braid, 600 V or 3,000 V, 130°C.
VHF
Very high frequency, the band extending from 30 to 300 MHz (television channels 2 to 13 and most FM radio) as designated by the Federal Communications Commission.
VIDEO PAIR CABLE
A transmission cable containing low-loss pairs with an impedance of 125 ohms. Used for TV pick ups, closed-circuit TV, telephone carrier circuits, etc.
VLF
Very low frequencies, the band extending from 10 to 30 kHz, as designated by the Federal Communications Commission.
VOICE PAIR CABLE
A transmission cable containing low-loss pairs with an impedance of 125 ohms. Used for TV pick ups, closed-circuit TV, telephone carrier circuits, etc.
VOLTAGE
Electrical potential or electromotive force expressed in volts.
VOLTAGE BREAKDOWN
A test to determine the maximum voltage insulated wire can withstand before failure.
VOLTAGE DROP
The voltage developed across a conductor by the current and the resistance or impedance of the conductor.
VOLTAGE RATING
The highest voltage that may be continously applied to a wire in conformance with standards or specifications.
VW-1
Vertical wire flame test. Formerly designated as FR1. A UL fire rating for single conductor cables. The test is described in UL Standard 1581.
W
(1) Symbol for watt or wattage, (2) A UL cable type. Heavy duty portable power cable, one to six conductors. 600 V, without grounds.
WALL THICKNESS
The thickness of the applied insulation or jacket.
WICKING
The longitudinal flow of a liquid in a wire or cable due to capillary action.
WIRE
A rod or filament of drawn or rolled metal whose length is great in comparison with the major axis of its cross section.
WIRE BRAID
Flexible wire constructed of small size strands in tubular form. Used for shielding or connections where constant flexing is required.
WIRE GAUGE (AWG)
The American Wire Gauge, originally called Brown & Sharpe Gauge. A system of numerical wire sizes starting with the lowest numbers for the largest sizes. Gauge sizes are each 20.6% apart based on the cross-sectional area.
WIRE NUT
A closed-end splice that is screwed on instead of crimped.
WIRE WRAPPING TOOLS
Portable electric tools and automatic stationary machines used to make solderless wrapped connections of wires to terminals.
WIRE-WRAPPED CONNECTION
A solderless connection made by wrapping bare wire around a square or rectangular terminal with a power or hand tool.
X
Symbol for reactance.
XHHW
A UL cable type. Cross-linked polyethylene insulated small diameter building wire rated 75°C wet and 90°C dry.
XLP
Cross-linked polyethylene. Also written XLPE.
XPLE
Cross-linked polyethylene.
Z
Symbol for impedence.
“F” TYPE CONNECTOR
A low cost connector used by the TV industry to connect coaxial cable to equipment.
