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Abrasion - The destruction of a material caused by scraping or rubbing against a rough, hard surface.

Abrasion Machine - A laboratory device for determining the abrasion resistance of wire and

cable. The two standard types of machines are the squirrel cage, with square steel bars, and the abrasive grit type.

Abrasion Resistance - The ability of a wire or cable jacket to resist surface wear.

AC - Abbreviation for alternating current. See alternating current. Also abbreviated as ac.

Accelerated Life Test - A test in which a cable is subjected to extreme conditions to determine the life of a cable.

Accelerator - Chemical additive which hastens chemical reaction, e.g., a compound added

to rubber or Neoprene® mixtures to reduce curing time. Neoprene® is a trademark of the DuPont de Nemours Co.

ACR - Designation for cable with corona resisting insulation.

ACRS - Aluminium conductor, steel reinforced. Aluminium wires stranded around a steel core. Usually used for high voltage cross-country transmission lines.

Adapter - a) Device used for joining two fibre optic connectors together. b) A device for connecting two parts (of different diameters) of an apparatus.

Adhesive - Usually a synthetic material which, when applied to tapes, potting operations, etc., permits materials to be bonded together.

Admittance - Symbol Y. The reciprocal of impedance.

Given by the formula:

where G is the conductance, B the susceptance,. Since impedance, Z, is given by: z = R + iX

where R and X are the resistance and reactance, respectively, then:

AEC - Atomic Energy Commission. The government agency which oversees all atomic energy projects.

Aerial Cable - A cable suspended in the air on poles or other overhead structures.

AIEE - Formerly American Institute of Electrical Engineers. Now called the Institute of Electrical and

Electronic Engineers (IEEE).

Air Spaced Coax - A coaxial cable in which air is basically the dielectric material. The conductor may be cantered by means of a spirally wound synthetic filament, beads, or braided filaments. This construction is also referred to as an air dielectric.

Aircraft Ignition Cable - A high tension cable designed for use in the ignition systems of internal combustion aircraft engines.

Aircraft Wire - An electrical wire primarily designed for the extreme conditions (temperature, altitude, solvents, fuels, etc.) of airborne equipment.

AL - Abbreviation for aluminium.

Alkali - A soluble salt obtained from the ashes of plants and consisting largely of potassium or sodium carbonate.

All Rubber Cable - A cable in which all voids between conductors are filled with a rubber com- pound. This construction gives greater resistance to impact, adds strength, and reduces the tendency to kink. It also reduces flexibility.

Alloy - A metal made by the fusion of two or more metals.

AL/MY- Abbreviation for Aluminium Mylar®. Sometimes called out as ALMY. Mylar® is a trademark of

the DuPont de Nemours Co.

ALS - A type of cable consisting of insulated conductors enclosed in a continuous, closely fitting

aluminium tube.

Alternating Current - An alternating current is one where the direction of current is reversed at regular intervals. The rate at which reversals occur is expressed in cycles per second (Hertz or Hz).

Abbreviated as AC or ac.

Alumel® - An alloy used for thermocouple and thermocouple extension wire. Almelo is a trademark

of the Hoskins Mfg. Co.

Aluminum Conductor - A wire or group of wires of aluminium, not insulated from each other, suitable for carrying electrical current.

am - Abbreviation for amplitude modulation. Also abbreviated as AM.

Ambient Temperature - The temperature of a medium (gas or liquid) surrounding an object.

American Wire Gauge - Abbreviated AWG. See AWG.

AMP - Abbreviation for ampere. See Ampere.

Ampacity - See current carrying capacity.

Ampere - The unit expressing the rate of flow of an electrical current. One ampere is the current flowing through one ohm resistance with one volt potential. Abbreviated as amp.

Amplifier - A device usually employing electron tubes or transistors to obtain amplification of voltage, current, or power.

An - Literally “aircraft number”. For example, AN-6 signifies a wire size of No. 6 AWG.

Analog - Being or relative to a mechanism in which data is represented by continuously varying physical quantities. Opposite - digital.

Annealed Wire - Wire which has been softened by heating and gradually cooling. Also called soft

drawn wire.

Annular Conductor - An annular conductor consists of a number of wires stranded in three reverse concentric layers around a saturated hemp core.

Anode - Positive pole of an electric source. Opposite - cathode.

ANSI - Abbreviation for American National Standards Institute. A federation of trade, technical, professional organizations, government agencies, and consumer groups. Coordinates standards development and publishes standards. Operates a voluntary certification program. Used to be called the American Standards Association (ASA).

Antenna WIRE - A wire usually of high tensile strength such as Copper weld®, bronze, etc., with or

without insulation used as an antenna for radio and electronic equipment. Copper weld® is a trademark

of the Copper weld Steel Company.

Antioxidant - A substance which prevents or slows down oxidation of material exposed to air.

Approx. - Abbreviation for approximate.

Aramid - A lightweight strong heat-resistant aromatic polyamide material used in fibre optic strength


Armature Wire - Stranded annealed copper wire, straight lay, soft loose white cotton braid. It is used for low voltage, high current rotor winding motors and generators. Straight lay permits forming in armature slots and compressibility.

Armor - An outer braid of metal or spiral steel tapes, primarily for the purpose of mechanical protection. Generally placed over the outer sheath.

Aromatic - An organic material composed of benzene in a ring structure.


B - Symbol for susceptance. See susceptance.

B & S GAUGE - Brown and Sharpe wire gauge used for describing different sizes of copper conductors. It is the same as AWG (American Wire Gauge). See AWG.

Backbone - A transmission network that carries information in a fibre optic system. Mainly for indoor applications between floors and areas with different types of cables.

Backshell Mold - An aluminium mold used to mold a rubber or Neoprene® covering over the back shell of a conductor or plug after it is connected to a cable. The compound is usually chemically cured. Neoprene® is a trademark of the DuPont de Nemours Co.

BALCO® - An alloy of 70% nickel and 30% iron. It is used in devices where self-regulation by temperature is required. Wilbur Driver Company trademark for a resistance wire.

Band Marking - A circular band applied at regular intervals to the insulation of a conductor for the

purpose of color coding or circuit identification.

Banded Cable - Two or more cables which have been banded together by stainless steel strapping.

Bandwidth - The frequency range of transmitted electrical or optical signals, expressed in Hertz. The greater or higher the bandwidth, the greater the information carrying capacity.

Bare Conductor - A conductor not covered with any insulating material.

Base Band - The frequency band occupied by all the transmitted modulating signals.

Battery Cable - A single conductor cable either insulated or uninsulated used for carrying current

from batteries to the point where power is needed. May also be used for grounding.

Baud - Unit of measure for data transmission speed representing bits per second, e.g., 9,600 baud =

9,600 bits per second (bps).

BC - Abbreviation for bare copper.

2BC - Abbreviation for double bare copper shield.

BCCS - Abbreviation for bare copper-clad steel.

BC-S - Abbreviation for double shield; 1 bare copper,

1 silver.

Beaded Coax - A coaxial cable in which the dielectric consists of beads made of various materials.

Bell Wire - Common term for wire primarily used for making doorbell and thermostat connections.

Belt (Belted Type Cable) - Refers to the number of layers of insulation on a conductor or number of layers of jacket on a cable.

Bend Radius - The radius of curvature that an optical fiber cable can bend without causing harmful

effects on the optical or mechanical performance of the cable.

Bending Loss - In a fiber optic system a form of increased attenuation caused by: a) Having the fiber curved around a restrictive radius of curvature; or b) Micro bends caused by minute distortions in the fiber imposed by externally induced disturbances. Excessive b ending loss may result from poor drawing or cable manufacturing technique.

Bending Radius - Radius of curvature around which a fibre is bent under a stated pulling force.

Berc - Abbreviation for beryllium-copper alloy.

Bias - a) A voltage applied to a device to establish a reference level for operation. b) A high frequency voltage combined with an audio signal to reduce distortion.

Binder - A spirally served tape or thread used for holding assembled cable components in place awaiting subsequent manufacturing operations.

Blasting Wire - Wire used for detonating explosives. It is usually a very inexpensively constructed


BLK - Abbreviation for black.

BMS - Abbreviation for Boeing Material Specification.

Bond Strength - Amount of adhesion between bonded surfaces, e.g., in cemented ribbon cable.

Bondable Wire - An insulated wire whose surface has been specially treated to make it possible to adhere to other materials such as potting compounds. The term usually refers to extruded PTFE insulated wires. The etching process roughens the surface of the insulation permitting an interlocking effect with potting compounds.

Bonded Construction - A type of insulation construction in which the glass braid and nylon jacket are bonded together as in certain wire sizes of MILDTL- 5086 Type II.

Boot - A protective covering over any portion of a cable or conductor in addition to its jacket or insulation.

BPS - Abbreviation for bits per second.

Braid - A fibrous or metallic group of filaments interwoven in cylindrical form to form a covering over

one or more wires. It can be made of materials such as cotton, glass, nylon, or copper fibers. Usually fibrous braid is saturated with an impregnant to protect it against moisture and fraying.

Braid Angle - The smaller of the two angles formed by the shielding strand and the axis of the

cable being shielded.

Braided Wire - Woven bare or tinned copper wire used as shielding for wires, cables, and ground wire for batteries or heavy industrial equipment. There are many different types of constructions.

Breakdown Of Insulation - Failure of an insulation resulting in a flow of current through the

insulation. It may be caused by the application of too high a voltage or defects or decay in the insulation.

Breakdown Voltage - The voltage at which the insulation between two conductors breaks down.

Breaking Strength - The maximum load that a conductor can withstand when tested in tension

to rupture. This force is usually expressed in pounds (lbs) or kilograms (kgs).

Breakout - A breakout is a joint where a conductor or conductors break out from a multi-conductor cable to complete circuits at various points along the main cable. The rest of the conductors continue on within the jacket. The breakout may itself be jacketed and the joint sealed.


c - Abbreviation for centimeter. Also abbreviated cm.

C - Abbreviation for Centigrade. A scale for measuring temperature, water freezes at 0° C and boils at

100° C. See Celsius temperature scale.

Cable - a) 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. b) A single conductor larger than 9 AWG.

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 Core - The portion of an insulated cable lying under the protective covering or jacket.

Cable Filler - The material used in multi-conductor cables to occupy the spaces formed by the

assembly of components thus forming a core of the desired shape (normally cylindrical).

Cable Pullers - A cable puller is a tool for pulling cables through a conduit made of metal, plastic,

rubber, or Neoprene®. Neoprene® is a trademark of the DuPont de Nemours Co.

Cable Sheath - A cable sheath is a covering of rubber, Neoprene®, resin, or lead over a wire or

cable core. Neoprene® is a trademark of the DuPont de Nemours Co.

Cabling Factor - Symbol K. A constant used in determining the approximate finished O.D. of an

unshielded, unjacketed cable. D = Kd, where D is the diameter, K is the factor, and d is the diameter

of one insulated conductor. A separate constant is used based on the number of conductors used (see Cable Design Formulas page 200).

CAD BR - Abbreviation for cadmium bronze.

Cadmium - A bluish-white malleable ductile toxic bivalent metallic element used in protective platings

and in bearing metals.

Caged Armor - The armor wires within a polyethylene jacket to increase mechanical protection and tensile strength. Often used in submarine cables.

Capacitance - Capacitance is that property of a system of conductors and dielectrics which permits the storage of electricity when potential differences exist between the conductors. The value depends largely on the surface area of the plates, distance between them, and the composition of the medium between the plates. Abbreviation CAP. The unit of measure is farad (f).

Capacitance, Direct - The capacitance measured directly from conductor to conductor through a single insulating layer.

Capacitance, Mutual - The capacitance between two conductors with all other conductors, including shield, short-circuited to ground.

Capacitance, Unbalanced - An inequality of capacitance between the wires of two or more pairs which results in a transfer of unwanted signal from one pair to others.

Concentric Stranding - A central wire or core surrounded by one or more layers of helically wound strands in a fixed round geometric arrangement. Generally each layer, after the first, has six more strands than the preceding layer and is applied in a direction opposite to that of the layer under it.

Concentricity - In a wire or cable, the measurement of the location of the center of the conductor

with respect to the geometric center of the surrounding insulation.

COND. - Abbreviation for conductor. See conductor.

Conductance - Symbol G. The measure of the ability of a substance to conduct electricity. The ratio of the current flow to the potential difference causing

the flow.

Current - The rate of flow of electricity. Usually measured in amperes. Symbol I.

Current Carrying Capacity - The maximum current an insulated conductor can continuously carry without exceeding its insulation and jacket temperature limitations. Also called ampacity.


db - Abbreviation for decibel(s). See decibel.

db LOSS - The loss of signal over a path or conductor,expressed in decibels.

DC - Abbreviation for direct current. See direct current.Also abbreviated dc.

DCR - Abbreviation for direct current resistance. The resistance offered by any circuit to the flow of

direct current.

DEC - Abbreviation for Digitial Equipment Corporation.

DECA - A prefix to a unit, denoting a multiple of ten

(10) of that unit.

DECI - A prefix to a unit, denoting a sub multiple of one-tenth (10 -1) of that unit.

DECIBEL - A unit used to express ratios of sound or signal power, defined by the following formula where n is the number of decibels.

n = 10 log 10 ( P2 / P1 )

Where P1 and P2 are the power levels. Since decibels represent a ratio, it is necessary to establish a reference level in order to indicate an absolute level. For sound, the reference level is a pressure of 0.0002 microbar. Abbreviated as db.

Degree Rise - The amount of increase in temperature caused by the introduction of electricity

into a unit.

Delay Line - A conductor that is made of a specific material in a specific size and length that will permit the delay of an electrical impulse for a predetermined specific length of time. The delay is measured in microseconds or nanoseconds.

Density - The distribution of a quantity (as mass, electricity, or energy) per unit, usually of space.

Desiccant - Water or moisture absorbent material used to prevent moisture from damaging packaged equipment or other merchandise.

Design Voltage - Voltage at which a cable is designed for maximum work.

Dielectric - Any insulating material that is a non-conductor of electricity. Abbreviated as dielect.

Dielectric Absorption - That property of an imperfect dielectric whereby there is an accumulation of electric charge within the body of the material when it is placed in an electric field.

Dielectric Constant - The factor by which the electric field strength in a vacuum exceeds that in the dielectric for the same distribution of charge. Symbol K. The K for air is 1.0.

Dielectric Loss - Energy dissipated as heat when

the dielectric is placed in a varying electric field.

Dielectric Strength - The maximum potential gradient (volts per mil) a dielectric will stand without breaking down; the voltage stress required to puncture an insulation of known thickness (in volts per unit, usually volts per mil.)

Digital - Of or relating to calculation by numerical methods or by discrete units. Opposite - analog.

Diode - Any electronic device that has only two electrodes. There are several different types of

diodes, their voltage characteristics determining their application. Diodes are most commonly used

as rectifiers.

Direct Burial Cable - A cable installed directlyin the earth without use of an underground conduit. Also called "burial cable".

Direct Current - A direct current is one which flows in one direction. Further classifications of direct currents are: a) Continuous currents which are steady, non pulsating direct currents; b) Constant currents, which continue to flow for a considerable time in the same direction and with unvarying intensity; and c) Pulsating currents, which are regularly varying continuous currents. Abbreviations DC and dc.


Earth Fault - A fault that occurs when a conductor is accidentally connected to earth or when

the resistance to earth of an insulator falls below aspecific value.

Earth Potential - The potential of a large conducting body, such as the earth, taken to be

the arbitrary zero in the scale of electrical potential. Synonymous with zero potential.

ECM - Abbreviation for Electronic Counter Measure. The use of equipment to prevent or induce jamming of electronic equipment, missile systems, radar, radio, and other devices.

ECTFE - Abbreviation for ethylene chlorotrifluoroethylene copolymer. See ethylene chlorotrifluoroethylene. Trade name Halar®. Halar® is a trademark of the Allied Chemical Co.

EEA - Abbreviation for ethylene-ethyl acrylate copolymer.

EHF - Abbreviation for extremely high frequency. See frequency band.

EIA - Abbreviation for Electronics Industries Association. Formerly know as RETMA (Radio Electronics Television Manufacturers Association).

Elastomer - A rubberlike substance.

Electrical Duct - Any electrical conduit or other raceway round in cross section, approved or

listed for use underground, and embedded in earth or concrete.

Electro Tinned - Wire tinned with pure tin using an electrolytic process.

Electromotive Force - Pressure or voltage. The force which causes current to flow in a circuit.

The algebraic sum of the potential differences in acircuit equals the EMF, which is measured by the

energy liberated when unit electric charge passes completely round the circuit. A battery of EMF, E,

will supply a current, I, to an external resistance, R:

E = I (R + r) where r is the internal resistance of the battery. The term "electromotive force" strictly applies to asource of electrical energy but is sometimes misused as being equivalent to potential difference. Symbol E. Abbreviated as EMF.

Elongation - The state of being elongated or lengthened.

EMC - Abbreviation for electromagnetic compatibility. No emission of interference exceeding FCC limits.

EMF - Abbreviation for electromotive force. See electromotive force.

EMI - Abbreviation for electromagnetic interference.

EMP - Abbreviation for electromagnetic pulse.

Enameled Wire - A conductor with a baked-on varnish enamel; may be 7 AWG through 50 AWG.

Intended for use in winding motors, coils, transformers, and other applications of similar usage.

Energize - To apply rated voltage to a circuit or device, such as the coil of a relay, in order to activate it.

Energy - The capacity for performing work.

EP - Abbreviation for ethylene propylene.

EPDM - Abbreviation for ethylene propylenediene monomer rubber.

EPN - Abbreviation for extended performance network cable.

EPOXY - A potting resin used in bonding, e.g., to bond PTFE wire to pot connectors to assure that

they are moisture proof.

EPR - Abbreviation for ethylene propylene copolymer rubber. It has properties similar to butyl rubber. The polymer is chemically cross-linked.

ESI - Abbreviation for electrostatic interference.

Etched Wire - A process applied to PTFE wire in which the wire is passed through a sodium bath to create a rough surface to allow epoxy resin to bond the PTFE.

ETFE - Abbreviation for ethylene tetrafluoroethylene. See ethylene tetrafluoroethylene.


f - Abbreviation for farad. See farad.

F - Abbreviation for Fahrenheit. See Fahrenheit.

FAA - Abbreviation for Federal Aeronautics Administration.

Fahrenheit - A scale for measuring temperature. Water freezes at 32° F and boils at 212° F. Abbreviated


FARAD - A unit of capacitance. Usually expressed in microfarads (μF) one-millionth (10-6) of a farad or picofarads (pf) one-trillionth (10-18) of a farad. Abbreviation

Fatigue Resistance - Resistance to metal crystallization that occurs when the conductors or wires break from flexing.

Fault Current - A current that may flow through a circuit or device as a result of a fault, such as a

defect in the insulation.

FDDI - Abbreviation for fiber distributed data interface.

FEP - Abbreviation for fluorinated ethylene propylene. It was formerly called X-100 or FEP-100. This is a fluorocarbon resin.

FHPE - Abbreviation for foamed high density polyethylene.

Fiber Optics - Transmission of energy by light through glass fibers.

Field - Area through which passes electric and/or magnetic lines of force.

Filler - a) Fillers are used in multi-conductor cable to occupy the voids formed by the assembled conductors. This is done so that the resulting configuration will be round. b) An inert substance added to a compound to improve properties or decrease cost.

Flame-Resistance - The ability of a material not to

propagate flame once the heat source is removed.

Flame-Retardant - Ability of a material to prevent the spread of combustion by a low rate of travel so the flame will not be conveyed.

Flashover - A disruptive discharge in the form of an arc or spark between two electrical conductors or between a conductor and earth.

Flashover Voltage - The voltage between two conductors at which flashover just occurs. The dry flashover voltage is the voltage at which flashover occurs when the conductors are separated by a

clean dry insulator. The wet flashover voltage is the voltage at which flashover occurs when the clean

insulator is wet


g - Abbreviation for gram.

G - Symbol for conductance. See conductance.

G. Cable - G. cable is a type W or power cable with ground wires. The total CM (circular mil) area of the ground wires is approximately one-half to three-quarters of the CM area of one of the conductors.

GAUGE - A term used to denote the physical size of a wire.

GC - Abbreviation for ground conductor.

GFI - Abbreviation for Ground Fault Interrupter. A protective device that detects abnormal current flowing to ground and then interrupts the circuit.

G-GC - Type G-GC mining cable with grounding conductor and a ground check conductor.

GHz - Abbreviation for gigahertz. See gigahertz.

GIGA - A prefix to a unit, denoting a multiple of one billion (10 9) of that unit.

Gigahertz - A term for one billion (10 9 ) cycles per second. Used to replace the more cumbersome

term kilomegacycle. Abbreviation GHz.

Glass Braid - Used to provide thermal and/or mechanical protection to the underlying insulation

of certain types of conductors.

GPU - Abbreviation for Ground Power Unit. A GPU is a mobile power generator used typically at airports.

Graded Index - In fiber optic cable the refractive index profile that varies with the radius of the core. The refractive indices decrease from the center axis out. The purpose is to reduce modal dispersion and thereby increase fiber bandwidth.

Grommet - A flexible loop that serves as a fastening, support, or reinforcement; an eyelet of firm material to strengthen or protect an opening or to insulate or protect something passed through it.

Ground - An object that makes an electrical connection with the earth; a large conducting body (as the earth) used as a common return for an electrical circuit and as an arbitrary zero potential; synonym for earth.

Ground Fault - A failure of transmission involving insulation to shield or insulation to ground wire.


H - Abbreviation for henry (unit of measure of inductance).

H-FILM® - High temperature polyimide Kapton® film. H-FILM® and Kapton® a re trademarks of the DuPont de Nemours Co.

Halar® - Ethylene chlorotrifluoroethylene or ECTFE copolymer. A high temperature insulation. Halar® is a trademark of the Allied Chemical Co. See ethylene chlorotrifluoroethylene.

Halogen - Any of the five elements fluorine, chlorine, bromine, iodine, and astatine that form part of

group VII A of the periodic table and exist in the free state normally as diatomic molecules.

HAM - An amateur radio operator.

Hard Drawn - The conductor is work hardened in the drawing process. Hard drawn refers to the temper of conductors that are not annealed after drawing.

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.

Heat Endurance - The time of heat aging that a material can withstand before failing a specific

physical test.

HF - a) Heavy Formvar Magnet Wire. Soft bare copper wire with baked synthetic insulation overall. b) Abbreviation for high frequency. See frequency band.

HF/LS/LT - Abbreviation for halogen-free, low smoke, low toxicity.

HMWPE - Abbreviation for high molecular weight polyethylene.


I - Symbol used to designate current. See current.

IACS - Abbreviation for International Annealed Copper Standard. Refined copper for electrical conductors: 100% conductivity at 20° C for 1 m X 1 mm2 has 1/58 ohm resistivity, 8.93 (changed to 8.89 in 1977) grams per mm2 density, 0.000017 per degree C coefficient of linear expansion, and 1/254.45 per degree C coefficient of variation of resistance.

IC - Abbreviation for integrated circuit.

ICEA - Abbreviation for Insulated Cable Engineers Association, formerly IPCEA.

ID - Abbreviation for identification.

I.D. - Abbreviation for inside diameter.

IEC - Abbreviation for International Electrotechnical Commission, similar to the International Standards Organization (ISO).

IEEE - Abbreviation for Institute of Electrical and Electronic Engineers. Formerly American Institute

of Electrical Engineers (AIEE) and Institute of Radio Engineers (IRE).

IMP - Abbreviation for impedance. See impedance.

Impact Strength - A test for determining the mechanical punishment a cable can withstand without physical or electrical breakdown by impacting with a given weight, dropped a given distance, in a controlled environment.

Impedance - A measure of the response of an electric circuit to an alternating current. Measured

in ohms (volts per ampere). Symbol Z. The current is opposed by the capacitance and inductance of

the circuit in addition to the resistance. The total opposition to current flow is the impedance

Induced Current - An electric current that flows in a conductor as a result of a changing magnetic flux density, in which lines of magnetic flux intersect with the conductor.

Inductance - The property of a circuit or circuit element that opposes a change in current flow,

thus causing current changes to lag behind voltage changes. It is measured in henrys. Symbol L.

Induction - The phenomenon of a voltage, magnetic field, or electrostatic charge being produced in

an object by lines of force from the source of such fields.

Inductive Coupling - Cross talk resulting from the electromagnetic field of one conductor on


Insertion Loss - The total optical power loss caused by the insertion of an optical component

such as a connector, splice, or coupler.

Insulation - That portion which is relied upon in a cable to segregate and protect the conductor

from the other conductors, conducting parts, or from ground.

Insulation Level - The impulse voltage breakdown of cables and equipment.

Insulation Resistance - The resistance offered by an insulating material to the flow of current resulting from an impressed DC voltage.

Insulator - a) A nonconducting substance such as porcelain, plastic, glass, rubber, etc; b) a device made of such material used for separating or supporting conductors to prevent undesired flow of electricity.


J-BOX - Abbreviation for junction box. A box for joining different runs of raceway or cable, plus space for connecting and branching the enclosed conductors.

Jacket - A covering over insulation usually nonmetallic, plastic, rubber, cotton, Neoprene®, fluoropolymer, or glass. Neoprene® is a trademark of the DuPont de Nemours Co.

JAN-C-17A - Joint Army-Navy specifications covering coaxial cables used for high frequency applications in radio, television, radar, etc.

JAN-C-76A - Joint Army-Navy specifications covering radio hook-up wire. Types SRIR, SRHV, WL, and SRRF. Superseded by MIL-W-76.

Joule - The unit of measure for energy or work. The international joule is equal to the work required

to maintain a current of one ampere for one second in a resistance of one ohm.

Jumper - Usually a temporary connection. A short length of conductor to connect between terminals, across a break in a circuit, or around an instrument.

Jute Filler - Rope like strands of material used in cables for filling in the voids to form a rounded

final cable shape.


K - Abbreviation for Karma® . Karma® is a trademark of the Driver Harris Company.

K Band - A band of microwave frequencies. See frequency band.

Kapton® - Trade name for polyimide resin. See polyimide. Kapton® is a trademark of the DuPont de Nemours Co.

Karma® - Trade name of the Driver Harris Company for a resistance wire composed of 74.5% nickel, 20% chromium, 2.75% aluminum, and 2.75% copper. Abbreviated K.

Kevlar ® - Trademark of the DuPont de Nemours Co. for the para-aramid fiber polyparaphenylene

terephthalamide. See polyparaphenylene terephthalamide.

kgs - Abbreviation for kilograms.

kHz - Abbreviation for kilohertz. See kilohertz.

Kilo - A prefix to a unit, denoting a multiple of one thousand (1,000) of that unit; a prefix used in computing to denote a multiple of one thousand, twenty four (210).

Kilohertz - One thousand (1,000) cycles per second. Abbreviation kHz.

Kilovolt - One thousand (1,000) volts. Abbreviation kV.

Kilovolt Ampere - One thousand (1,000) volts x amperes. Abbreviation kVA

Kilowatt - A unit of measure of power equal to one thousand (1,000) watts. Abbreviation kW.

Kirchoff’S Laws - The algebraic sum of the currents at any point in a circuit is zero; the algebraic

sum of the product of the current and the impedance in each conductor in a circuit is equal to the electromotive force in the circuit.

km - Abbreviation for kilometer (1,000 meters).


L - Symbol for inductance. See inductance.

L Band - A band of microwave frequencies. See frequency band.

Lacquer Finish - A finish applied over braided wire or cable for appearance, for moisture proofing, to reduce friction, and resist abrasion.

Laminates - A buildup of layers of material to increase thickness as in braid varnished cambric (VCB).

Lamp Cord - Flexible stranded conductor cord, rubber or plastic insulated, used in wiring of lamps,

household fans, and similar appliances. Not subject to hard usage. UL approved.

LAN - Abbreviation for Local Area Network. See local area network.

Lapel Mike Cable - Small O.D., flexible microphone cable.

Laser - Acronym from light amplification by stimulated emission of radiation. A source of intense

monochromatic coherent radiation in the visible, ultraviolet, or infrared regions of the electromagnetic

spectrum. The narrow beam can be either pulsed or continuous.

Latex - Rubber material used for insulation of wire.

Launch Fiber - An optical fiber used to couple and condition light from an optical source into an

optical fiber. Often the launch fiber is used to create an equilibrium modal distribution in multi-mode fiber. Also referred to as launching fiber.

Lay - The length measured along the axis of a wire or cable required for a single strand (in stranded wire) or conductor (in cable) to make one complete turn around the axis of the conductor or cable.

lbs - Abbreviation for pounds.

LDPE - Abbreviation for low density polyethylene.

Leaching And Non Leaching - In a leaching wire, the plasticizer will migrate or leave the vinyl

compound when exposed to the heat of baking. The wire so treated becomes brittle and hard. A

non leaching wire will retain its plasticizer under extreme temperature conditions and remain flexible

after baking. Non leaching wire is desirable for use as motor lead wire.

Lead Cured - A cable that is cured or vulcanized in a metallic lead mold.

Lead-In - The cable that connects the active part of an aerial to the transmitter or receiver.

Leakage - The passage of an electric current along a path other than that intended due to faulty insulation or isolation in a circuit, component, device, or other piece of apparatus.

LF - Abbreviation for low frequency. See frequency band.

Line Voltage - The voltage existing in a cable or circuit.


mA - Abbreviation for milliampere, one-thousandth (10-3) of an ampere.

MAG. OX. - Abbreviation for magnesium oxide.

Magnet Wire - Insulated copper wire used for winding coils, motors, and transformers.

Mains - The source of domestic electrical power distributed nationally throughout the U.K. The mains

frequency is the frequency at which the electrical power is supplied. This is 50 hertz in the U.K. and

60 hertz in the U.S.

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.

MAT - Abbreviation for material.

MATV - Abbreviation for Master Antenna TV.

MAX - Abbreviation for maximum.

Mbps - Abbreviation for megabits per second.

MC - Abbreviation for megacycle.

MCM - Abbreviation for one thousand (1,000) circular mils, e.g., 500 MCM = 500,000 circular mils.

Mechanical Splice - A fiber splice accomplished by fixtures or materials, rather than by thermal fusion. Index matching material may be applied between the two fiber ends.

Medium Frequency - See frequency band.

Mega - A prefix to a unit, denoting a multiple of one million (1,000,000) of that unit.

Megahertz - One million (1,000,000) cycles per second. Abbreviation MHz.

Megawatt - One million (1,000,000) watts. Abbreviation MW.

Melamine - A thermosetting resin chemically known as melamine formaldehyde. It has excellent

resistance to acids and alkalies and good resistance to water and solvents. Has high strength, high insulation resistance as compared to plastics.

MESA - Abbreviation for Mining Enforcement and Safety Administration. Formerly PBM (Pennsylvania

Bureau of Mines).

Messenger - The linear supporting member, usually a high strength steel wire, used as the supporting element of a suspended aerial cable. The messenger may be an integral part of the cable or exterior to it.

meter - The unit of length defined as the length of the path travelled by light in vacuum during a time

interval of 1/299,792,458 of a second. One meter equals 39.3701 inches. Abbreviation m.

MF - Abbreviation for medium frequency. See frequency band.

Mfd - Abbreviation for microfarad. See microfarad.

MFG. - Abbreviation for manufacture/manufacturing.

MFT - Abbreviation for one thousand (1,000) feet.

MHD - Abbreviation for medium hard drawn copper wire.

Mho - The unit of conductivity. The reciprocal of an ohm.

MHz - Abbreviation for megahertz, one million (1,000,000) cycles per second. Formerly mc. See


MI - Nomenclature for mineral insulated cable, made with one or more conductors using mineral for insulation and overall solid metal tube sheath.

MICA - A transparent silicate which separates into layers and has high insulation resistance, high dielectric strength, and high heat resistance.

MICRO - A prefix to a unit, denoting a submultiples of one-millionth (10-6) of that unit.

MIL SPEC - Abbreviation for military specification.

MIL STD - Abbreviation for military standard.

MIL-W - Military wire specification.

Modulus OF ELASTICITY - The ratio of stress to strain in an elastic material.


N - a) Abbreviation for newtons. See newton. b) Abbreviation for nichrome.

N/A - Abbreviation for not applicable.

NA - Abbreviation for numerical aperture. See numerical aperture.

NANO - A prefix to a unit, denoting a submultiples Of one-billionth (10-9) of that unit.

Nanometer - One billionth (10-9) of a meter. Abbreviated nm.

Nanosecond - One-billionth (10-9) of a second.

Net Loss - The difference between the attenuation and the gain in any circuit, device, network, or

transmission line.

Neutral - a). Having no net positive or negative electric charge at earth potential. b). c Denoting the

line that completes the domestic mains supply and is connected to earth at the power station.

Newton - The unit of force in the metric system of physical units that is of such size that under its

influence a body whose mass is one kilogram would experience an acceleration of one meter per second

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. The nickel has been rolled and fused to the copper

before drawing. It has a very high resistivity and can operate at extremely high temperatures. Abbreviated NCC and NC.


O.D. - Abbreviation for outside diameter.

OEM - Abbreviation for Original Equipment Manufacturer.

OFC - Abbreviation for optical fibre conductive general purpose cable.

OFCG - Abbreviation for optical fibre conductive fire resistant general purpose cable.

OFCP - Abbreviation for optical fibre conductive plenum cable.

OFCR - Abbreviation for optical fibre conductive riser cable.

Offgassing - Percentage of a specified gas released during the combustion of an insulating or

jacketing material.

OFHC - Abbreviation for oxygen free, high conductivity copper. It has no residual deoxidant, 99.95%

minimum copper content and an average annealed conductivity of 100%.

OFN - Abbreviation for optical fibre non conductive general purpose cable.

OFNG - Abbreviation for optical fibre non conductive fire resistant general purpose cable.

OFNP - Abbreviation for optical fibre non conductive plenum cable.

OFNR - Abbreviation for optical fibre non conductive riser cable.

OHM - The unit of measure for electrical resistance, reactance, and impedance. A constant current of one ampere produces a force of one volt. Symbol

OHM’S LAW - The electric current, I, flowing in a conductor or resistor is linearly proportional to the

applied difference, V, across it. From the definition of resistance, R, Ohm’s law can be written:

V = IR (i.e.,Volts = Current x Resistance.)


PAIR - Two insulated wires of a single circuit associated together.

PAIRING - The union of two insulated single conductors through twisting.

PAN CURED - Method of vulcanizing. Coils of unvulcanized insulated wire are coiled in pans and

vulcanized under pressure with live steam.

PAP - A commonly used term for air core (unfilled) direct burial telephone cable with a corrugated aluminium shield.

PAPER INSULATED - Insulation used for telephone cable, high voltage cable, and magnet wire. Has

high dielectric strength; however, pretty much passé because of better insulations.

PCTFE - Abbreviation for polychlorotrifluorethylene. One of the fluoropolymers which has a high dielectric strength used at temperatures to 250° C.

PE - Abbreviation for polyethylene. A thermoplastic insulation having excellent electrical properties. Also abbreviated as poly and pol.

PEAK VOLTAGE - The maximum voltage reached during an alternation of frequency.

PEF - Abbreviation for polyethylene foam. Also abbreviated as PE Foam.

PE FC - Abbreviation for polyethylene flooding compound.

PE Foam - Abbreviation for polyethylene foam. Also abbreviated as PEF.

POLYESTER - Any of a group of polymers that consists basically of repeated units of an ester and are used especially in making fibbers or plastics. More specifically, polyethylene tetephthalate which is used extensively in the production of a high strength moisture resistant film used as a cable core wrap.

POLYETHYLENE - A thermoplastic material, polymerized ethylene. They are basically pure hydrocarbon resins, often with small amounts of other additives to impart needed properties. All members of the polyethylene family are excellent dielectrics. Electrically they are far superior to any other extrudable dielectric in use today. Outstanding electrical properties include high insulation resistance, high dielectric strength, low dielectric constant, low dielectric loss at all frequencies,

excellent resistance to cold flow, and good abrasion resistance. One or more members of the

polyethylene family also have the following properties: Resistance to sunlight, weather, chemicals, and flame. Polyethylene is widely used for insulation on telephone, signal and control cables, high frequency electronic cables, high voltage and low voltage power cables, line wire, neutral supported secondary and service drop cables. They are suitable for direct earth burial. Temperature ratings vary with type and application from 75° C up. Abbreviation PE, POL, and POLY.

POLYIMIDE - A relatively high temperature plastic developed for use as a dielectric or jacketing material, Kapton®. Usually laminated to FEP and used as heat sealable tape. It does not burn and has high abrasion resistance. Kempton® is a trademark of the DuPont de Nemours Co.

POLYMER - A material of high molecular weight formed by the chemical union on monomers.

POLYOLEFIN - A family of thermoplastics based upon the unsaturated hydrocarbons known as olefins. When combined with butylenes or styrene polymers, they form compounds such as polyethylene and polypropylene.


This synthetic has high tensile strength at low weight, low elongation to break, high modulus (structural rigidity), low electrical conductivity, high chemical resistance, low thermal shrinkage, high toughness (work-to-break), excellent dimensional stability, high cut resistance, flame-resistant, and self-extinguishing properties. Trade name KEVLAR ®. KEVLAR ® is a trademark of the DuPont de Nemours Co.

POLYPROPYLENE - A thermoplastic polymer of propylene with good electrical characteristics, high

tensile strength, and resistance to heat.

POLYSTYRENE - A rigid transparent thermoplastic of good physical and electrical insulating properties used especially in melded products, foams, and sheet materials. Abbreviation PS.

POLYSULFONE - A polymer highly resistant to mineral, acid, alkali, and salt conditions. Good dielectric properties up to 350° F.

POLYTETRAFLUOROETHYLENE - This is modified ETFE, a copolymer of ethylene and tetrafluoroethylene. This is the most thermally stable and chemically resistant carbonaceous insulating compound. It is unaffected by sunlight, moisture, and practically all chemicals. Temperature range is -90° C to 250° C and electrical properties are very constant over the temperature range and a wide range of frequencies. This insulation may be applied by extrusion, taping, dip-coating, and in cases where other material is used, by dispersion coating. Both conventional and ribbon

type wires and cables are made as well as magnet wire. This insulation material is used as dielectric,

insulation, and extruded jackets. Abbreviation is PTFE. Most common trade name is PTFE®. PTFE®

is a trademark of the DuPont de Nemours Co.

POLYURETHANE - Enamel that has excellent moisture resistance, easily soldered, also has excellent winding properties as magnet wire insulation. Abbreviation PU.

POLYVINYLCHLORIDE - A family of insulating compounds whose basic ingredient is either polyvinylchloride or its copolymer with vinyl acetate, in combination with appropriate plasticizers, stabilizers, fillers, and pigments. Like many other plastic materials, these insulations can be compounded to provide a wide variety of properties for various applications. Among the properties obtained are: Resistance to moisture, cold, heat, flame, oils, solvents, chemicals, and ozone. Electrical properties are adequate for low voltage power applications. Temperature ratings up to 105° C are recognized by UL for certain applications. These insulations are widely used for types T and TW

building wires, series street lighting cable, machine tool wiring, hook-up and appliance wiring, overhead line wire, control and signal cables, and many others. Known as PVC or Vinyl. Abbreviation PVC.

POWER FACTOR - The ratio of resistance, R, to impedance, Z. The ratio of the actual power of an

alternating current to apparent power. Mathematically, the cosine of the angle between the voltage applied and the current resulting.

PTFE - Abbreviation for polytetra fluoroethylene


Q BAND - A band of microwave frequencies. See frequency band.

QPL - Abbreviation for Qualified Products List issued by a United States Government Agency.

QUAD - A four conductor cable.


R - a) Symbol for resistance (see resistance) or resistor. b) 600 volt copper conductor stranded or

solid, rubber insulated, cotton braid (rubber filled tape 6 AWG and larger). Cotton braid saturated

with moisture resisting, flame-retarding compound smoothly finished. Used for power wiring. c) Abbreviation for riser.

RATED TEMPERATURE - The maximum temperature at which an electric component can operate for extended periods without loss of its basic properties.

RATED VOLTAGE - The maximum voltage at which an electric component can operate for extended periods without undue degradation or safety hazard.

REACTANCE - The part of the total impedance of a circuit not due to pure resistance, measured in ohms. Symbol X. It is the imaginary part of the complex impedance, Z given by:

Z = R +iX

where R is resistance, X is reactance. Reactance is due to the presence of capacitance

or inductance in a circuit. The effect of reactance is to cause the voltage and current to become out of- phase.

RECEIVER - A detector and electronic circuitry to change optical signals to electrical signals.

REEL - Circular container on which wire is wound for storage or transit, usually made of wood or metal.

REFLECTION LOSS - The part of a signal which is lost due to reflection of power at a line discontinuity.

REFLOW SOLDERING - The process of connecting two solder coated conductive surfaces by remelting of the solder to cause fusion.

REFRACTIVE INDEX - The ratio of the speed of light in a vacuum to the speed of light in a material. Also called Index of Refraction.

REFRACTION - Deflection from a straight path undergone by a light ray or energy wave in passing

obliquely from one medium (as air) into another (as glass) in which its velocity is different.

RESISTANCE - The tendency of a material to resist the passage of an electric current and to convert

electrical energy into heat energy. Symbol R. It is the ratio of the applied potential difference across

a conductor to the current flowing through it (see Ohm’s law). If the current is an alternating current,

the resistance, measured in ohms, is the real part of electrical impedance, Z, given by the formula:

Z = R +Ix

RESISTIVITY - An intrinsic property of a material equal to the resistance per unit length and unit cross

sectional area. Reciprocal of conductivity. The lower the resistivity of a material the better conductor it

is. Materials can be classified as conductors, semiconductors, or insulators according to their resistivity. Conductors have a resistivity of 10-6 to 10-8 ohms per meter, semi-conductors have a resistivity of 10-6 to 10-7 ohms per meter, and insulators have a resistivity of 10-7 to 10-23 ohms per meter.

RoHS - RoHS is the acronym for Restriction of Hazardous Substances. RoHS, also known as Directive 2002/95/EC, originated in the European Union and restricts the use of specific hazardous materials found in electrical and electronic products. All applicable products in the EU market after July 1, 2006 must pass RoHS compliance. For the complete directive, see Directive 2002/95/EC of the European Parliament. The substances banned under RoHS are lead (Pb), mercury (Hg), cadmium (Cd), hexavalent chromium (CrVI), polybrominated biphenyls (PBB) and polybrominated diphenyl ethers (PBDE).


S - a) Abbreviation for silver-plated copper. Also abbreviated as SPC. b) 600 volt senior service rubber insulated portable cord. 18 AWG two conductor through 6 AWG four conductor.

2S - Abbreviation for silver-plated copper double shield.

SA - a) Abbreviation for silver-covered alloy. b) Nomenclature for silicone rubber insulation with

high temperature barrier or glass overall for use up to 125° C.

S BAND - A band of microwave frequencies. See frequency band.

SC - Abbreviation for silver-covered copper. Also abbreviated as SCC.

2SC - Abbreviation for two silver-plated copper shields.

SCB - Abbreviation for silver-plated cadmium bronze. Also abbreviated as SCCad Br.

SCBerC - Abbreviation for silver-covered beryllium copper alloy.

SCC - Abbreviation for silver-covered copper. Also abbreviated as SC.

SCCA - Abbreviation for silver-covered copper-clad aluminium. Also abbreviated SCCAL.

SCCad Br - Abbreviation for silver-covered cadmium bronze. Also abbreviated as SCB

SCCAL - Abbreviation for silver-covered copper-clad aluminium. Also abbreviated SCCA.

SCCS - Abbreviation for silver-covered copper-clad steel. Also abbreviated as SCS.

SCHSCA - Silver-coated high strength copper alloy.

SCPE - Semi-conducting polyethylene.

SCS - Abbreviation for silver-covered copper-clad steel. Also abbreviated as SCCS.

SCW - Abbreviation for silver-plated Copper weld® conductor. Copper weld® is a trademark of the Copper weld Steel Company.

SD - Abbreviation for soft drawn (annealed).

SECONDARY INSULATION - A high resistance dielectric material which is placed over primary

insulation to protect it from abrasion.

SECTOR STRAND - A group of wires laid in triangular shape with rounded corners, for use as one conductor of a three conductor cable with 120° angle between faces, and with 90° angle for a four

conductor cable.

SEGMENTAL CONDUCTOR - In single conductor cables one million (1,000,000) CM or more, the

conductors are divided into three or four segments, insulated from each other by paper tapes, to reduce current resistance in AC circuits.

SELENIUM CURE - Process used in curing Neoprene ® and rubber jacketed wires and cables. The process makes a dense, tough, durable jacket. Neoprene® is a trademark of the DuPont de Nemours Co.

SELF-EXTINGUISHING - The characteristic of a material whose flame is extinguished after the igniting flame is removed.

SELF-SUPPORTING AERIAL CABLE - A cable consisting of one or more insulated conductors assembled or cabled with a steel core or attached to a separate steel cable, which supports the weight of the cable. It may be from pole to pole or in a vertical position on a tower.

SELF-SUPPORTING CABLE - A cable with a steel support strand capable of supporting the cable weight across spans.

SEMI-CONDUCTING JACKET - A jacket having a sufficiently low resistance so that its outer surface

can be kept at substantially ground potential by a grounded conductor in contact with it at frequent


SEMI-CONDUCTOR - Any of a class of solids whose electrical conductivity is between that of a conductor and that of an insulator in being nearly as great as that of a metal at high temperatures and nearly absent at Low temperatures.

SINTERED - Usually refers to curing of PTFE. To cause to become a coherent mass by heating without melting. .

SOLDEREZE - Magnet wire insulated with polyurethane base enamel

SPARK TEST - A test given to wire or cable to determine if there are defects in the insulation. A semi-destructive test, in that it will find weak spots in insulation by a spark breaking through thin spots or pinholes in the jacket when a high voltage potential from the conductor to an outside source is applied. Where these sparks emanate, the cable is cut, thus shortening the cable. This test should only be run once on a wire or cable.

SPC - Abbreviation for silver-plated copper. Also abbreviated as S.

SPECIFIC GRAVITY - The ratio of the density (mass per unit volume) of a material to that of water.

STRANDED CONDUCTOR - A conductor made with a specified number of strands. Rope lay strand, for example, is a conductor made of multiple groups of strands (filaments). A 7 x 19 rope lay strand has 19 wires laid into a group and then seven such groups cabled laid into a conductor.

SUSCEPTANCE - Symbol B. The imaginary part of the admittance, Y, which is given by:

Y = G + iB

where G is the conductance


T - The old UL designation for switchboard wire insulated with thermoplastic lead wire.

TA - The UL designation for switchboard wire insulated with thermoplastic and a high temperature barrier.

TAGT - Stranded nickel-clad copper conductor insulated with fused PTFE tape, high temperature

Barrier, and PTFE impregnated glass braid. 600 volt, 250° C rating.

TANK TEST - A voltage dielectric test in which the test sample is submerged in water and voltage is applied between the conductor and water as ground.

TCCS - Abbreviation for tinned copper-clad steel.

TCW - Abbreviation for tinned Copper weld,. Copper weld is a trademark of the Copper weld Steel


PTFE® - PTFE® is DuPont de Nemours Co.'s trade name for their family of fluorocarbon resins

including PTFE® TFE (tetrafluoroethylene), PTFE®

FEP (fluorinated ethylene propylene), and PTFE® PFA (perfluoroalkoxy). See tetrafluorethylene and



- The amount of resistance change of a material per degree of temperature change.

TEMPERATURE RATING - The maximum temperature at which an insulating material may be used

in continuous operation without loss of its basic properties.

TENSILE STRENGTH - The pull stress required to break a given specimen. In fiber optics, the maximum allowed pulling force until a specific attenuation is reached. The stated value is short-term.

THERMAL RATING - The maximum and/or minimum temperature at which a material will perform its function without undue degradation.

THERMAL RESISTANCE - The resistance of a substance to conductivity of heat.

THERMAL SHOCK - A test to determine the ability of a material to withstand heat and cold by subjecting it to rapid and wide changes in temperature.

THERMOCOUPLE - A union of dissimilar metals in which a voltage is generated due to a change in

temperature. The voltage is usually in micro or milli volts.

THERMOCOUPLE EXTENSION - Same as thermocouple lead wire.

THERMOCOUPLE LEAD WIRE - An insulated pair of wires used from the couple to a junction box or to the recording instrument.

TINNED COPPER - Tin coating added to a copper conductor or braid to aid in soldering and inhibit corrosion. Abbreviated as TC.


UF - Single or multi-conductor, with or without ground, used for direct burial underground feeders and branch circuits between buildings, yard lights, floodlights, and similar installations.

UG - The two letter designation that precedes the number on connectors for coaxial cable. It means

Universal Government.

UHF - Abbreviation for ultra high frequency. See frequency band.

UL - Abbreviation for Underwriters Laboratories Inc. A non profit organization that maintains and operates laboratories for the examination and testing of devices, systems and materials relative to life, fire and casualty, hazards, and crime prevention. Founded in 1894, the enterprise is sponsored by the National Board of Fire Underwriters.

UNBALANCED CIRCUIT - A transmission line in which voltage on the two conductors are unequal

with respect to ground, e.g., a coaxial cable.

UNILAY CONDUCTOR - A central core surrounded by one or more concentric layers of helically wound strands in a fixed geometrical arrangement with the direction of lay the same for each layer and the central core.

UNSINTERED - Means uncured. This word is usually used to differentiate between cured and uncured PTFE tape.

UNSWEEPT - Coaxial cable that has not had an attenuation check (sweep test).

URC - Nomenclature for weatherproof wire.

USASI - Abbreviation for United States of American Standards Institute. Superseded ASA and in turn

was superseded by ANSI.

USE - Neoprene® jacketed underground service entrance cable. Neoprene® is a trademark of the DuPont de Nemours Co.

UTP - Abbreviation for unshielded twisted pair.

UV - Abbreviation for ultraviolet.


V - Abbreviation for voltage. See voltage.

VA - Abbreviation for volt-ampere. A designation of power in terms of volts and amperes.

V BAND - A band of microwave frequencies. See frequency band.

VEL. - Abbreviation for velocity.

VELOCITY OF PROPAGATION - Is the ratio of the speed of an electric signal down a length of cable

compared to the speed of light in free space. All insulated cables have this ratio and it is expressed in percentage. It is the reciprocal of the square root of the dielectric constant of the cable insulation. For

example, in the case of coaxial cables with polyethylene dielectric, this ratio is 65% to 66%.

VERTICAL RISER CABLE - Steel wire armoured power cable for vertical runs in a building.

VERY HIGH FREQUENCY - See frequency band. Abbreviation VHF.

VERY LOW FREQUENCY - See frequency band. Abbreviation VLF.

VHF - Abbreviation for very high frequency. See frequency band.

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.

VITON® - A synthetic family of elastomer for high performance jacketing material. It possesses very

good resistance to chemicals, heat, fire, and good mechanical properties. Viton ® is a trademark of Du- Pont Dow Elastomers.

VLF - Abbreviation for very low frequency. See frequency band.

VOLT - A unit of measure of electromotive force. One volt is the amount of pressure that will cause

one ampere of current in one ohm of resistance. Abbreviation V.

VOLTAGE - The term most often used in place of electromotive force, potential, potential difference,

or voltage drop to designate the electric pressure that exists between two points and is capable of

producing a current when a close circuit is connected between two points.

VOLTAGE BREAKDOWN - A test to determine maximum voltage of insulated wire before electrical

current leakage through insulation occurs.

VOLTAGE RATING - The highest voltage which may be applied to a wire or cord for continuous service in conformance with the governing standards or specifications.


RESISTANCE) - The electrical resistance between opposite faces of a 1 centimetre cube of insulating

material, commonly expressed in ohms per centimetre.


W - a) Abbreviation for watt. See watt. b) Heavy duty portable power cable, Neoprene® jacket, in

single or multiple conductors, 600 volt. Neoprene® is a trademark of the DuPont de Nemours Co. c)

Abbreviation for with.

WALL THICKNESS - Refers to insulation thickness or jacket thickness that has been applied.

WATER ABSORPTION - A test to determine the water absorbed by a material after a given immersion period.

WATER BLOCKED CABLE - A multi-conductor cable having voids filled to prevent water flow or wicking.

WATT - The unit of measure of electric power. One watt is equivalent to the power represented by one ampere of current under a pressure of one volt in a DC circuit. Abbreviation W.

WAVEGUIDE - A transmission line that consists of a suitably shaped hollow conductor, which may be filled with a dielectric material and that, is used to guide ultrahigh frequency electromagnetic waves propagated along its length. The most common shapes of waveguide are rectangular and cylindrical; the most common dielectric is air. A cylindrical waveguide is sometimes known as a wave duct; one that contains a solid rod of dielectric is a uniconductor waveguide. If a wide range of frequencies is to be transmitted, a ridged waveguide may be used. The presence of the ridges extends the possible range of frequencies that may be propagated in a particular transmission mode but the transmission is greater than in the equivalent rectangular waveguide.

WAVEGUIDE DISPERSION - Dispersion caused by the fact that light travels at different speeds in the

core and cladding of single-mode fibbers.

WAVELENGTH - The distance, measured in the direction of propagation, of a repetitive electrical pulse or waveform between two successive points that are characterized by the same phase of vibration.

W BAND - A band of microwave frequencies. See frequency band.

WICKING - The longitudinal flow of a liquid in a wire or cable due to capillary action.

WIRE - A slender rod or filament of drawn metal. The term is a generally used one, which may refer to any single conductor. If larger than 9 AWG or multiple conductors, it is usually referred to as a cable.

WIRE BRAID - Flexible wire constructed of small size strands woven together in tubular form. Used for shielding or connections where constant flexing is required.

WIRE GAUGE - 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 cross sectional area. Abbreviation AWG.


X - Symbol for reactance. See reactance.

X-100 - See FEP.

X BAND - A band of microwave frequencies. See frequency band.

XETFE - Abbreviation for cross-linked extruded, modified ethylene tetrafluoroethylene copolymer.

See ethylene tetrafluoroethylene.

X GUIDE - A transmission line that is used for the propagation of surface waves and consists of a

length of dielectric material with a X-shaped cross section.

XHHW - Cross-linked polyethylene insulated, rated at 90° C in dry locations and 75° C in wet locations.

XL - Abbreviation for cross-linked insulation. See cross-linked.

XLAP - Abbreviation for cross-linked extruded alkane- imide polymer.

XLETFE - Abbreviation for cross-linked ethylene tetrafluoroethylene copolymer. See ethylene tetrafluoroethylene copolymer.

XLP - Abbreviation for cross-linked polyethylene. Also abbreviated as XLPE.

XLPA - Abbreviation for cross-linked extruded polyalkene.

XLPE - Abbreviation for cross-linked polyethylene. Also abbreviated as XLP .

XL POLYOLEFIN - Cross-linked polyolefin.

XLPVF - Abbreviation for cross-linked extruded polyvinylidene Fluoride


Y - Symbol for admittance. See admittance.

yrs. - Abbreviation for years.


Z - Symbol for impedance. See impedance.

ZERO POTENTIAL - See earth potential.

ZIP CORD - Parallel cable that can be easily separated by pulling apart.