Glossary of Terms


19-Wire Combination Unilay

Combination Unilay Conductors are 19 strand constructions with a straight central wire, an inner layer of six wires of the same diameter as the central wire, and an outer layer consisting of six wires of the same diameter as the central wire alternated with six smaller wires. The smaller wires have a diameter of .732 times the diameter of the central wire. The 12 wires in the outer layer and the six wires of the inner layer all have the same length of lay and direction of lay.



Acronym for the American Association of Railroads, an industry trade group which primarily represents the major freight railroads of North America (Canada, Mexico and the United States).

Abrasion Resistance

Ability of a wire, cable or material to resist surface wear.


Alternating Current, or AC, is an electrical current that frequently reverses direction. AC electricity is measured according to its cycles, with one complete cycle being counted each time a given current travels in one direction and then doubles back on itself. It is expressed in cycles per second (hertz or Hz).

AC Resistance

The total resistance offered by a device in an alternating current circuit due to inductive and capacitive effects, as well as the direct current resistance.

Accelerated Aging

Accelerated aging is a testing method that utilizes aggravated conditions of heat, oxygen, sunlight, vibration, etc. to speed up the normal aging processes of items. It is used to help determine the long term effects of expected levels of stress within a shorter time, usually in a laboratory with controlled standard test methods.

Accelerated Life Test

An Accelerated Life Test is a test in which certain factors (such as voltage, temperature) to which a cable is subjected are increased in magnitude above normal operating values to obtain observable deterioration within a reasonable period of time and thereby affording some measure of the probable cable life under operating voltage, temperature, etc.


A chemical additive which hastens a chemical reaction under specific conditions.


Acronym for an Aluminum Conductor Steel-Reinforced cable.


Acronym for an Aluminum Conductor Steel-Reinforced cable which uses Class A zinc coated steel wire.


Acronym for an Aluminum Conductor Steel-Reinforced cable which uses Class B zinc coated steel wire.


Acronym for an Aluminum Conductor Steel-Reinforced cable which uses Class C zinc coated steel wire.


A chemical additive used to initiate the chemical reaction in a specific chemical mixture.

Active Current

In an alternating current, a component in phase with the voltage; the working component as distinguished from the idle or wattless component.

Active Pressure

In an AC circuit, the pressure which produces a current as distinguished from the voltage impressed upon the circuit.


The state in which two surfaces are held together by interfacial forces which may be chemical or mechanical in nature.

Adjacent Conductor

Any conductor next to another conductor either in the same multiconductor cable layer or in adjacent layers.


The measure of the ease with which an alternating current flows in a circuit. The reciprocal of impedance.

Aerial Cable

A cable suspended in the air on poles or other overhead structure.


The irreversible change in properties or appearance of a material over time and under specific conditions (usually accelerated representations of environmental states, such as high temperature, oxygen or other various conditions).

Air Core Cable

A telephone cable in which the interstices in the cable core are not filled with a moisture barrier.

Air Spaced Coaxial Cable

Coaxial cable in which air is the essential dielectric material. A spirally wound synthetic filament or spacer may be used to center the conductor.


Abbreviation for Aluminum Mylar, a combination tape with one side of aluminum, used for shielding


A metal formed by combining two or more different metals to obtain desirable properties.


An aerial telephone cable having an aluminum shield.


A type of cable consisting of insulated conductors enclosed in a continuous closely fitting aluminum tube.

Alternating Current

AC, or Alternating Current, is an electrical current that frequently reverses direction. AC electricity is measured according to its cycles, with one complete cycle being counted each time a given current travels in one direction and then doubles back on itself. It is expressed in cycles per second (hertz or Hz).

Alternating Current Resistance

The resistance offered by any circuit to the flow of alternating current.

Alternating Voltage

Impedance through which alternating current is flowing.


Conditions existing at a location prior to the energizing of equipment (example: ambient temperature).

Ambient Temperature

Any all-encompassing temperature within a given area.

American National Standards Institute

The American National Standards Institute, or ANSI, (previously known as ASA) is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems and personnel in the United States.

American Society for Testing and Materials

The American Society for Testing and Materials, or ASTM, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services. Known as ASTM International until 2001.

American Society of Mechanical Engineers

The American Society of Mechanical Engineers, or ASME, is a professional association that promotes the art, science, and practice of multidisciplinary engineering and allied sciences around the globe via continuing education, training and professional development, codes and standards, research, conferences and publications, government relations, and other forms of outreach.

American Wire Gauge

American wire gauge, or AWG, is a standardized wire gauge system used since 1857 predominantly in the United States and Canada for the diameters of round, solid, nonferrous, electrically conducting wire. The cross-sectional area of each gauge is an important factor for determining its current-carrying capacity. Based on a circular mil system where 1 mil equals .001 inch.


Amp, or ampere, is the SI unit of electric current. One ampere represents the current flowing through one ohm of resistance at one volt potential.


Ampacity, or current carrying ampacity, is the maximum current an insulated wire or cable can safely carry without exceeding either the insulation or jacket material limitations.


Ampere, or amp, is the SI unit of electric current. One ampere represents the current flowing through one ohm of resistance at one volt potential.

Ampere's Law

The magnetic intensity at any point near a current carrying conductor can be computed on the assumption that each infinitesimal length of the conductor produces at the point of an infinitesimal magnetic density. The resulting magnetic intensity at the point is the vector sum of the contributions of all the elements of the conductor.


Relief of mechanical stress through heat and gradual cooling. Annealing copper renders it less brittle.

Annular Conductor

A number of wires stranded in three reversed concentric layers around a core.


The electrode through which a direct current enters the liquid, gas or other discrete part of an electrical circuit; the positively charged pole of an electrochemical cell.


ANSI, or The American National Standards Institute, (previously known as ASA) is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems and personnel in the United States.


A substance which prevents or slows down oxygen decomposition (oxidation) or a material exposed to air.


A substance which prevents or slows down material degeneration due to ozone reaction.

Appliance Wiring Material

Appliance Wiring Material, or AWM, is a recognized component used in UL listed or classified products.


Per the OSHA definition, a product that has been tested to standards and found suitable for general application, subject to limitations outlined in the nationaly recognized testing lab's listing


A luminous glow formed by the flow of electric current through ionized air, gas or vapor between separated electrodes or contacts.

Arc Over Voltage

The minimum voltage required to create an arc between electrodes separated by a gas or liquid insulation under specified conditions.

Arc Resistance

The time required for an arc to establish a conductive path in a material.

Area of Conductor

The size of a conductor cross-section, measured in circular mils, square inches, etc.


A braid or wrapping of metal, usually steel, placed over the outer sheath for mechanical protection.

Armored Cable

A cable having a metallic covering for protection against mechanical injury.


ASME, or the American Society of Mechanical Engineers, is a professional association that promotes the art, science, and practice of multidisciplinary engineering and allied sciences around the globe via continuing education, training and professional development, codes and standards, research, conferences and publications, government relations, and other forms of outreach.


A filled direct burial telephone cable used in areas subject to rodent attack. ASP cables consist of a filled cable core, corrugated aluminum shield, corrugated steel tape, flooding compound and polyethylene jacket.


ASTM, or the American Society for Testing and Materials, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services. Known as ASTM International until 2001.

ASTM International

ASTM International, now known as ASTM, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services.


Power loss in an electrical system. In cables, attenuation is generally expressed in db per unit length, usually 1000 ft.

Audio Frequency

The range of frequencies audible to the human ear, usually 20 - 20,000 Hz.


Acronym for American Wire Gauge, a standardized wire gauge system used since 1857 predominantly in the United States and Canada for the diameters of round, solid, nonferrous, electrically conducting wire. The cross-sectional area of each gauge is an important factor for determining its current-carrying capacity. Based on a circular mil system where 1 mil equals .001 inch.


AWM, or Appliance Wiring Material, is a recognized component used in UL listed or classified products.



Abbreviation for Brown & Sharpe Wire Gauge, also known as American Wire Gauge (AWG).

Balanced Circuit

A circuit which is arranged so that the impressed voltages on each conductor of the pair are equal in magnitude but opposite in polarity with respect to ground.

Balanced Line

A transmission line consisting of two conductors of the same type, each of which have equal impedances along their lengths and equal impedances to ground and to other circuits. A balanced line offers good rejection of external noise.


A device for matching an unbalanced coaxial transmission line to a balanced two-wire system.

Band Marking

A continuous circumferential band applied to a conductor at regular intervals for identification.


The frequency range of transmitted electrical signals, expressed in Hertz.

Bare Conductor

A conductor with no coating or cladding on the copper.


Method of coiling into a fiber drum for shipment.


Acronym for Billion Conductor Feet, a quantity derived by multiplying the number of conductors in a cable by the amount of the cable. BCF is generally used to indicate plant capacity or an annual requirement.

Bend Radius

A term used to denote the minimum radius that an insulated cable may be safely bent during installation and use. A bend radius value is usually expressed as a whole number multiple (i.e. 8X) of a cables overall diameter.


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

Blown Jacket

Outer cable covering applied by controlled inflation of the cured jacket tube and then pulling the cable through it.


The attachment at an interface between an adhesive and an adherent or between materials attached together by adhesive.

Bond Strength

Amount of adhesion between surfaces, e.g., in bonded ribbon cable.


A device inserted into a line, or cable, to increase the voltage.


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


A fibrous or metallic group of filaments interwoven in cylindrical form to form a covering over one or more wires.

Braid Angle

The smaller of the two angles formed by the shielding strand and the axis of the cable being shielded.

Braid Carrier

A spool or bobbin on a braider which holds a group of strands or filaments consisting of a specific number of ends. The carrier revolves during braiding operations.

Braid Ends

The number of strands which make up one carrier. Strands are wound side by side on the carrier bobbin and lie parallel in the finished braid.

Branch Joint

A cable joint used for connecting one or more cables to a main cable.


The joining of ends of two wires, rods or groups of wires with a nonferrous filler metal at temperatures above 800F (427C).


A disruptive discharge through the insulation.

Breakdown of Insulation

Failure of insulation which results in a flow of current through the insulation. May be caused by the application of high voltage or by defects or decay.

Breakdown Voltage

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

Breaking Strength

The maximum tension load that a conductor attains before rupturing.


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.

British Standard Wire Gauge

A modification of the Birmingham Wire Gauge and the legal standard of Great Britain for all wires. Also known as Standard Wire Gauge (SWG), New British Standard (NBS), English Legal Standard and Imperial Wire Guide.


Acronym for bare soft copper, uncoated annealed copper.


A soft material which mechanically isolates individual fibers in a fiber optic cable or bundle from a small geometrical irregularities, distortions, or roughness of adjacent surfaces.

Building Wire

Wire used for light and power, 600 volts or less, which is usually not exposed to outdoor environment.

Bunch Strand

Any number of conductor strands twisted together in one direction which contain the same lay length.

Bunch Stranding

A group of wires of the same diameter twisted together without a predetermined pattern.

Bunched Stranding

Bunched stranding is composed of any number of strands twisted together in the same direction without regard to geometrical arrangement of the individual strands. Normal direction of lay is left-hand.


A number of fibers grouped together, usually carrying a common signal.

Buried Cable

A cable installed directly in the earth without use of an underground conduit. Also known as a "direct burial cable."


Wire used to connect two terminals inside of an electrical unit.


Joining of two conductors end-to end, with no overlap and with the axes in line.

Butt Splice

A splice wherein two wires from opposite ends butt against each other, or against a stop, in the center of a splice.

Butt Wrap

Tape wrapped around an object or conductor in a edge-to-edge condition.


Typically a group of eight binary digits.


C Symbol

Designation for capacitance, bias supply and centigrade.


A group of individually insulated conductors in twisted or parallel configuration, with or without an overall covering.

Cable Assembly

A completed cable and its associated hardware ready for install.

Cable Core

The portion of a cable lying under the outer protective covering.

Cable Filler

The material used in multiple conductor cables to occupy the spaces formed by the assembly of components, thus forming a core of the desired shape (normally cylindrical.)

Cable Jacket

The material, usually an extruded plastic or elastomer, applied outermost to a wire or cable to provide mechanical and environmental protection; often referred to as a sheath.

Cable Sheath

The material, usually an extruded plastic or elastomer, applied outermost to a wire or cable to provide mechanical and environmental protection; often referred to as a jacket.


The twisting together of two or more insulated conductors to form a cable.

Cabling Factor

Used in the formula for calculating the diameter of an unshielded, unjacketed cable. D=Kd, where D is the cable diameter, K is the factor and d is the diameter of one insulated conductor.

Caged Armor

A construction using wires within a jacket to increase mechanical protection and tensile strength; sometimes used in submarine cables.


Storage of electrically separated charges between two plates which have different potentials. The value depends largely on the surface area of the plates and the distance between them.

Capacitance (Unbalance to Ground)

An inequality of capacitance between the ground capacitance of the conductors of a pair which results in a pickup of external source of energy, usually from power transmission lines.

Capacitance (Unbalance)

An inequality of capacitance between the wires of two or more pairs which result in a transfer of unwanted signal from one pair to others.

Capacitive Coupling

Electrical interaction between two conductors caused by the capacitance between them.

Capacitive Reactance

The opposition to alternating current due to the capacitance of a cable, circuit or capacitor. Measured in ohms and equal to 1/6.28fC where f is the frequency in Hz and C is the capacitance in farads.


Two conducting surfaces separated by a dielectric material. The capacitance is determined by the area of the surface, types of dielectric, and spacing between the conducting surfaces.


The woven grouping of a braided shield, consisting of one or several parallel ends.


Negative pole of an electric source.

Cathodic Protection

The control of the electroytic corrosion of an underground or underwater metallic structure by the application of an electric current through a sacrificial anode in such a way that the structure is made to act as a cathode of an electrolytic cell.


Acronym for Community Antenna Television, a system of distributing television programs to subscribers via radio frequency (RF) signals transmitted through coaxial cables or light pulses through fiber-optic cables.


Acroynm for Closed Circuit Television. CCTV pertains to the use of video cameras to transmit a signal to a specific place, on a limited set of monitors. It differs from broadcast television in that the signal is not openly transmitted, though it may employ point to point (P2P), point to multipoint, or mesh wireless links.


Belgium approval agency; Comite Electrotechnique Beige Service de la Marque.

Cellular Polyethylene

Expanded or "foam" polyethylene consisting of individual closed cells suspended in a polyethylene medium.


European standards agency; European Committee for Electrotechnical Norms.

Certificate of Compliance

A certificate which proves that the product being shipped meets customer’s specifications.

Certified Test Report

A report providing actual test data on a cable. Tests are normally run by a Quality Control Department, which shows that the product being shipped conforms to test specifications.


Acronym for Code of Federal Regulations, the general and permanent rules published in the Federal Register by the executive departments and agencies of the Federal Government.

Characteristic Impedance

Characteristic Impedance refers to the impedance that, when connected to the output terminals of a transmission line of any length, makes the line appear infinitely long. The ratio of voltage to current at every point along a transmission line on which there are no stranding waves.


The quantity of electricity held statically in a condenser or on an insulated conductor.

Charging Current

The current produced when a DC voltage is first applied to conductors of an unterminated cable. It is caused by the capacitive reactance of the cable, and decreases exponentially with time.

Charging Time

The time required for the voltage between two conductors of a cable to acquire a value equal to 98.2% of the magnitude of an instantaneously applied DC voltage change.

Chlorinated Polyurethane

Chlorinated Polyethylene, or CPE, is widely used as a thermoplastic elastomer (TPE), rubber and modifier for resins (PVC, PE and ABS) because of its excellent resistance properties against heat, oil, chemical, fire and weather

Chlorosulfonated Polyethylene

Chlorosulfonated Polyethylene (CSPE) synthetic rubber, otherwise known Hypalon, is noted for its resistance to chemicals, temperature extremes, and ultraviolet light. Hypalon is a product of DuPont Performance Elastomers, a subsidiary of DuPont.


The complete path through which a current flows or part of the complete path, such as one conductor.

Circular Mil Area

The area of a circle one mil (.001") in diameter, 7.845 x 10-7 sq. in. Used in expressing wire cross sectional area.


A method of applying a layer of metal over another metal whereby the junction of the two metals in continuously welded.


Acronym for Circular Mil Area, a unit of area which is equal to the area of a circle with a diameter of one mil (one thousandth of an inch).


To cover with a continuous layer of compound (such as varnish) for purposes of finishing, protecting or enclosing. Usually comprises variable degrees of impregnation depending on the nature of the substance.


A material applied to the surface of a conductor to prevent environmental deterioration, facilitate soldering or improve electrical performance.

Coaxial Cable

A cable consisting of two cylindrical conductors with a common axis, separated by a dielectric.

Cold Blend Test

A test whereby a sample of wire or cable is wound around a mandrel of a specified size within a cold chamber at a specified temperature for a given number of turns at a given rate of speed. The sample is then removed and examined for deterioration in the materials and construction.

Cold Flow

Permanent deformation of the insulation due to mechanical force or pressure (not due to heat softening.)

Cold Test

Any test to determine the performance of cables during or after subjection to a specified low temperature for a specified time.

Color Code

A system for circuit identification through use of solid colors and contrasting tracers.

Common Axis Cabling

In multiple cable constructions, a twisting of all conductors about a "common axis" with two conductor groups then selected as pairs. This practice yields smaller diameter constructions that does a separate axis construction, but tends to yield greater susceptance to EMI and ESI.

Common Mode

Noise, caused by a difference in "ground potential." By grounding at either end rather than both ends (usually grounded at source) one can reduce this interference.

Compact Stranded Conductor

A unidirectional or conventional conductor manufactured to a specified diameter, approximately 8 to 10% below the nominal diameter of a noncompact conductor of the same cross sectional area.


The ability of dissimilar materials to exist in mutual proximity or contact without changing their physical or electrical properties.

Composite Cable

A cable consisting of two or more different types or sizes of wires.


An insulating or jacketing materials made by mixing two or more ingredients.


Compressed Stranding is a conventional conductor manufactured to a diameter not more than 3% below the nominal diameter of a noncompressed conductor of the same cross-sectional area.

Compressed Stranded Conductor

A conventional concentric conductor manufactured to a diameter not more than 3% below the nominal diameter of a non-compressed conductor of the same cross-sectional area.

Concentric Lay Cable

A multiple conductor cable composed of a central core surrounded by one or more layers of helically laid insulatedconductors. In the most common concentric lay constructions, all conductors are of the same size and the central (core) component is a single conductor. The direction of the lay is reversed for successive layers.

Concentric Strand

A group of uninsulated wires twisted so as to contain a center core with one or more distinct layers of spirally wrapped, uninsulated wires laid overall to form a single conductor. When more than one layer is present each layer must have a different lay length.

Concentric Stranding

A central wire surrounded by one or more layers of helically wound strands in a fixed round geometric arrangement


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.


The ability of a conductor to carry electric current. It is the reciprocal of resistance and is measured in ohms.


The capability of a material to carry electrical current-usually expressed as a percentage of copper conductivity (copper being 100%).


An uninsulated wire suitable for carrying electrical current.

Conductor Core

The center strand or member about which one or more layers of wires or members are laid helically to form a concentric-lay or rope-lay conductor.


A tube or trough in which insulated wires and cables are run.


A device used to physically and electrically connect two or more conductors.


A copper-nickel alloy usually consisting of 55% copper and 45% nickel. Also known as Eureka, Advance and Ferry. Its main feature is its resistivity which is constant over a wide range of temperatures.


The part of a connector which actually carries the electrical current which are touched together or separated to control the flow.

Continuity Check

A test to determine whether electrical current flows continuously throughout the length of a single wire or individual wires in a cable.

Continuous Vulcanization

Simultaneous extrusion and vulcanization of wire coating materials.

Control Cable

A multiconductor cable made for operation in control or signal circuits.


A polymer formed from two or more types of monomers.


Copper is a chemical element with the symbol Cu (from Latin: cuprum) and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity.

Copper-Clad Steel

Copper-Clad Steel (CCS), also known as copper-covered steel or the trademarked name Copperweld, is a bi-metallic product mainly used in the wire industry that combines the high mechanical resistance of steel with the conductivity and resistance to corrosion of copper


Copperweld, also known as Copper-Clad Steel (CCS), is a bi-metallic product mainly used in the wire industry that combines the high mechanical resistance of steel with the conductivity and resistance to corrosion of copper


A small, flexible insulated cable.


In cables, a component or assembly of components over which additional components (shield, sheath, etc.) are applied.


A discharge due to ionization of air around a conductor due to a potential gradient exceeding a certain critical value.

Corona Effect

In wiring, the effect produced when two wires of other conductors having a great difference of voltage are placed near each other.

Corona Loss

A loss or discharge which occurs when two electrodes having a great difference of pressure are placed near together.

Corona Resistance

The time that the insulation will withstand a specified level of field-intensified ionization that does not result in the immediate complete breakdown of the insulation.

Corona Test

A test to determine the ability of cable to withstand the formation of corona under an increasing applied voltage and to extinguish corona when a corona-producing voltage is reduced.


The deterioration of a material by chemical reaction or galvanic action.


CPE, or Chlorinated Polyethylene, is widely used as a thermoplastic elastomer (TPE), rubber and modifier for resins (PVC, PE and ABS) because of its excellent resistance properties against heat, oil, chemical, fire and weather


The minute cracks on the surface of plastic materials.


An acronym for Continuous Rigid Cable Support. Synonymous with tray.


The dimensional change with time of a material under load.


Electrical leakage on a solid dielectric surface.


Inter-molecular bonds between long chain thermoplastic polymers by chemical or electron bombardment means. The properties of the resulting thermosetting material are usually improved.


Used by pickup of stray energy. Also known as induced interference.


Ultra-High Strength Copper Alloy


Acronym for the Canadian Standards Association, the Canadian counterpart of the Underwriters Laboratories.


Acronym for Chlorosulfonated Polyethylene synthetic rubber. Otherwise known Hypalon, CSPE noted for its resistance to chemicals, temperature extremes, and ultraviolet light. Hypalon is a product of DuPont Performance Elastomers, a subsidiary of DuPont.


Cable tray frame rating.


CU is the chemical element for copper.


See Vulcanization.


The degree to which a wire tends to form a circle after removal from a spool. An indication of the ability of the wire to be wrapped around posts in long runs.


The rate of flow of electricity in a circuit, measured in amperes.

Current Carrying Capacity

Current carrying ampacity, or ampacity, is the maximum current an insulated wire or cable can safely carry without exceeding either the insulation or jacket material limitations.

Current Charging

The current needed to bring the cable up to voltage; determined by the capacitance of the cable. The charging current will be 90° out of phase with the voltage.

Current Density

The current per cross sectional area in units of amperes/meters

Current Penetration

The depth a current of a given frequency will penetrate into the surface of a conductor carrying the current.

Current Rating

The maximum continuous electrical flow of a current recommended for a given wire situation. Expressed in amperes.

Current-Carrying Capacity

The maximum current an insulated conductor or cable can continuously carry without exceeding its temperature rating. It is also called ampacity.


Resistance of solid material to penetration by an object under conditions of pressure, temperature, etc.

Cut-Through Resistance

The ability of a material to withstand mechanical pressure, usually a sharp edge or prescribed radius, without separation.


The complete sequence of alteration or reversal of the flow of an alternating electric current.



Acronym for direct current, a type of electric current which flows in only one direction.


Acronym for Direct Current Resistance; the resistance offered by any circuit to the flow of direct current.


A unit which expresses differences of power level.


Acronym for Diesel Electric Locomotive.

Delay Line

A cable made to provide very low velocity of propagation with long electrical delay for transmitted signals.

Derating Factor

A factor used to reduce the current carrying capacity of a wire when used in environments other than that for which the value was established.


Any insulating material between two conductors which permits electrostatic attraction and repulsion to take place across it.

Dielectric Absorption

The property of an imperfect dielectric where there is an accumulation of electric charges within the body of the material when it is placed in an electric field.

Dielectric Breakdown

The voltage at which a dielectric material is punctured, which is divisible by thickness to give dielectric strength.

Dielectric Constant (K)

The ratio of the capacitance of a condenser with dielectric between the electrodes to the capacitance when air is between the electrodes. Also called Permittivity and Specific Inductive Capacity.

Dielectric Strength

The voltage which an insulation can withstand before breakdown occurs. Usually expressed as a voltage gradient (such as volts per mil).

Dielectric Strength Testing

A common safety test for electrical products often called hi-pot testing. Voltages many times higher than normal operating voltages are applied across the insulation. This test not only proves the integrity of the insulation system but increases product reliability by detecting faulty workmanship.

Dielectric Test

A test in which a voltage higher than the rated voltage is applied for a specified time to determine the adequacy of the insulation under normal conditions.

Direct Burial Cable

A cable installed directly in the earth without use of an underground conduit. Also known as a "burial cable."

Direct Capacitance

The capacitance measured directly from conductor to conductor through a single insulating layer.

Direct Current

An electric current which flows in only one direction.

Direct Current Resistance

The resistance offered by any circuit to the flow of direct current.

Direction of Lay

The lateral direction in which a conductor or group of conductors of a cable run over the top of the cable as the elements recede from the observer looking along the axis of the cable. Direction of lay is expressed as left-hand or right-hand. ASTM symbols used to indicate directions of lay are s for left-hand and z for right-hand.

Dissipation Factor

The tangent of the loss angle of the insulating material. (Also referred to as loss tangent, tan S. and approximate power factor.)


Acronym for Diesel Locomotive.

Double Foot

Combined length of one linear foot of paired material; i.e., one double foot is equal to one foot of positive material plus one foot of negative material. Usually used in determining thermocouple wire loop resistance.

Double Shield

Combination shield usually consisting of alum/mylar and awoven braid shield

Drain Wire

In a cable, the uninsulated wire in intimate contact with a shield to provide for easier termination of such a shield to a ground point.


In wire manufacturing, pulling the metal through a die or series of dies to reduce diameter to a specified size.


The method of coiling wire into fiber drums for shipment.


An underground or overhead tube for carrying electrical conductors.

Duplex Insulated

In the thermocouple industry, a combination of dissimilar metal conductor of a thermocouple or thermocouple extension wire.


One of several measures of the hardness of a material. Hardness may be defined as a material's resistance to permanent indentation.



Voltage, electromotive force


British terminology for zero-reference ground


Like concentricity, eccentricity is a measure of the center of a conductor’s location with respect to the circular cross- section of the insulation. Expressed as a percentage of displacement of one circle within the other.


Acronym for Ethylene Chloro-Trifluoroethylene (Halar).

Eddy Current

An electric current induced in a conductor by a varying magnetic field.


Acronym for Electronic Industries Association.


A rubber-like substance.

Electrolytic Tough Pitch

A term describing the method of raw copper preparation which ensures a good physical and electrical grade copper finished product


Pertaining to the combined electric and magnetic fields associated with movements of electrons through conductors.

Electromagnetic Interference

A disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation emitted from an external source.

Electromotive Force

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

Electro-Motive Force

The force which determines the flow of electricity; a difference of electric potential


Pertaining to static electricity or electricity at rest. A constant intensity electric charge.


The fractional increase in length of a material stressed in tension.


A marker identification by means of thermal indentation leaving raised lettering on the sheath material of cable.

Emergency Overload

Load which occurs when larger than normal currents are carried through a cable or wire over a certain period of time.


Acronym for Electromagnetic Interference, a disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation emitted from an external source.


Acronym for Electrical Metallic Tubing

Enameled Wire

A conductor with a baked-on enamel film insulation. In addition to magnet wire, enameled insulation is used on thermocouple type wires and other wires.


In braiding, the number of essentially parallel wires or threads on a carrier.


To apply rated voltage to a circuit or device in order to activate it.


Acronym for Environmental Protection Agency, the federal regulatory agency responsible for keeping and improving the quality of our living environment.


Acronym for Electronic Point-of-Sale.


Acronym for Ethylene Propylene Rubber, an ozone resistant rubber consisting primarily of ethylene propylene copolymer (EPM) or ethylene propylene diene terpolymer (EPDM).


Equilay strand construction consists of the same lay length and lay direction in each layer. Normal direction of lay is left-hand.

Equilay Stranding

Equilay Concentric stand construction is characterized by a central wire surrounded by one or more layers of helically laid wires in a geometric pattern, with alternately reversed lay direction and the same lay length.


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


Acronym for Ethylene tetrafluoroethylene, otherwise known as Teflon.


Acronym for Electrolytic Tough Pitch Copper. ETPC has a minimum conductivity of 99.9%.

External Interference

The effects of electrical waves or fields which cause sounds other than the desired signal (static).

Extrudable Primary Insulations

Extrudable primary insulations are applied directly over the conductor and are often used for jackets. Materials include polyvinyl chlorides, polyethylenes, fluorocarbons, silicones, etc.


The process of continuously forcing both a plastic or elastomer and a conductor core through a die, thereby applying a continuous coating of insulation or jacket to the core or conductors.



Acronym for the Federal Aeronautics Administration.


A unit of electrical capacity.

Fatigue Resistance

Resistance to metal crystallization which leads to conductors or wires breaking from flexing.


Acronym for the Federal Communications Commission.


Acroynm for Fluorinated Ethylene Propylene, a "Teflon" fluorocarbon resin that is registered T.M. of the DuPont Company.


A thread or threadlike structure. Also, a single discrete element used to transmit optical (light wave) information.

Fiber Dispersion

Pulse spreading in a fiber caused by differing transit times of various modes.

Fiber Optics

A lightwave or optical communications system in which electrical information is converted to light energy, transmitted to another location through optical fibers, and is there converted back into electrical information.


Area through which pass electric and/or magnetic lines of force.

Figure 8 Cable

An aerial cable configuration in which the conductors and the steel strand which supports the cable are integrally jacketed. A cross section of the finished cable approximates the figure "eight".

Filled Cable

A telephone cable construction in which the cable core is filled with a material that will prevent moisture from entering or passing through the cable.


1) A material used in multiconductor cables to occupy large interstices formed by the assembled conductors. 2) An inert substance added to a compound to improve properties or decrease cost.


A thin plastic sheet.

Flame Resistance

The ability of a material to prevent the spread of combustion by a low rate of travel so the flame will not be conveyed.


The measure of the materials ability to support combustion.

Flammability Test

A test to determine the ability of a cable to resist ignition when placed near a source of heat of flame and to self-extinguish when removed from this source.

Flat Braid

A woven braid of tinned copper strands rolled flat at time of manufacture to a specified width.

Flat Cable

A cable with two smooth or corrugated (but essentially) flat surfaces.

Flat Conductor

A wire having a rectangular cross section as opposed to round or square conductors.

Flat Conductor Cable

A cable with a plurality of flat conductors.

Flex Life

The measurement of the ability of a conductor or cable to withstand repeated bending.


The ease with which a cable may be bent.


The quality of a cable or cable component which allows for bending under the influence of outside force as opposed to limpness which is bending due to the cable’s own weight.


Referring to a circuit which has no connection to ground.

Foamed Plastics

Insulations having a cellular structure.


Acronym for Fused Polyethylene Aluminum, a trademark of General Cable Corporation.


A flammability rating established by Underwriters Laboratories for wires and cables that pass a specially designed vertical flame test. This designation has been replaced by VW-1.


Number of times an alternating current reverses itself in one second. Expressed in Hertz (Hz), which is one cycle per second.

Fuse Wire

Wire made from an alloy that melts at a relatively low temperature.

Fused Spiral Tape

A PTFE Insulated hookup wire. The spiral wrapped conductor is passed through a sintering oven where overlaps are fused together.



Rubber-insulated, neoprene, Hypalon or CPE jacketed, portable power cable with two to five #8 AWG or larger conductors with ground wires.

Galvanized Steel Wire

Steel wire coated with zinc.

Gang Strip

Simultaneous stripping all conductors in a flat or ribbon cable.

Gas Filled Cable

A self-contained pressure cable in which the pressure medium is an inert gas having access to the insulation.


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


An instrument for detecting or measuring small electrical current.


Acronym for Ground Fault Interrupter, a protective device that detects abnormal current flowing to ground and then interrupts the circuit.


A portable power cable similar to Type G, but also having a ground check conductor.


A numerical prefix denoting one billion.


One gigahertz is equal to 1,000 megahertz (MHz) or 1,000,000,000 Hz. It is commonly used to measure computer processing speeds


A conducting connection between an electrical circuit and the earth or other large conducting body to serve as an earth thus making a complete electrical circuit.

Grounded Conductor

A system of circuit conductor that is intentionally grounded; usually colored white.

Grounded Neutral

Neutral wire that is mechanically connected to ground.

Grounding Conductor

A conductor used to connect equipment or the grounded circuit of a wiring system to a grounding electrode of electrodes; usually colored green.



A trade name of Allied Chemical for their copolymer or ethylene and chlorotriflurorethylene. Acronym ECTFE.

Hard Drawn Copper Wire

Copper wire that has not been annealed after drawing.


An arrangement of wires and cables, usually with many breakouts, which have been pulled together or pulled into a rubber or plastic sheath used to interconnect an electric circuit.

Hash Mark Stripe

A noncontinuous helical stripe applied to a conductor for identification.

Heat Distortion

Distortion or flow of a material or configuration due to application of heat.

Heat Endurance

The time of heat aging that a material can withstand before failing a specific physical or electrical test.

Heat Resistance

Ability of a substance to maintain physical and chemical identity and electrical integrity under specified temperature conditions.

Heat Seal

A method for sealing by thermal fusion.

Heat Shock

A test to determine stability of a material by sudden exposure to a high temperature for a short period of time.

Heavy Tinned Copper

Similar to tinned copper but with substantially greater tin thickness. Used with high frequency induction heaters to bond on the stripped area. The remaining length of wire retains it's original flexibility. Acceptable under UL, CSA, ASTM, MIL and most industry standards.

Helical Stripe

A continuous, colored spiral stripe applied to a conductor for circuit identification.


Unit of inductance such that the induced voltage in volts is numerically equal to the rate of change in current in amperes per second.

Hermetically Sealed

A gaslight enclosure that has been completely sealed by fusion or other comparable means.


A term replaced cycles-per- second as a unit of frequency.

Hi Pot

A test designed to determine the highest voltage that can be applied to a conductor without electrically breaking down the insulation.

High Voltage

Generally, a wire or cable with an operating voltage of over 35,000 volts.


DC high potential testing of medium and high voltage cables

Hook-Up Wire

A single insulated conductor used for low current, low voltage (usually under 600 volts) applications within enclosed electronic equipment.

Hot Tin Dip

A process of passing bare wire through a bath of molten tin to provide a coating.


Two-conductor, neoprene-insulated heater cord for use in damp locations.


Capable of absorbing and retaining moisture.


DuPont’s trade name for their Chlorosulfonated Polyethylene, an ozone resistant synthetic rubber.



Acronym for International Annealed Copper Standard


Acronym for International Association of Electrical Inspectors


Acronym for Insulated Cable Engineers Association (formerly IPCEA).


Inner Diameter.


Acronym for International Electrotechnical Commission, similar to the ISO in structure and scope.

IECA S-95-658-1999

Standard for nonshielded power cables rated 2000 volts or less for the distribution of electrical energy covers THHN/THWN, XHHW and RHH/RHW/USE cables


Acronym for Institute of Electrical and Electronics Engineers.


Acronym for Intermediate Metal Conduit


The total opposition that a circuit offers to the flow of alternating current or any other varying current at a particular frequency. It is a combination of resistance R and reactance X, measures in ohms.


Acronym for International Municipal Signal Association Specifications for Fire Alarm Cable.

Incoherent Source

A light source which emits wide, diffuse beams of light of many wave lengths.

Index Matching Fluid

Fluid with refractive index same as fiber core; used to fill air gap between fiber ends at connectors.

Induced Current

An electric current set up in a circuit by cutting lines of force; a current caused by electromagnetic induction.


The property of a circuit or circuit element that opposes a change in current flow, thus causing current changes to lag behind voltage changes.

Inductive Coupling

Crosstalk resulting from the action of the electromagnetic field of one conductor on the other.


A material having high resistance to the flow of electric current.

Insulation Level-100%

Cable for use on grounded systems or where the system is provided with relay protection such that ground faults will be cleared as rapidly as possible but in any case within one minute.

Insulation level-133%

Cable for use on grounded systems or where the faulted section will be de-energized in a time not exceeding one hour.

Insulation Resistance

Property of an insulating material which resists electrical current flow through the insulating material when a potential difference is applied.

Insulation Resistance (I.R.)

Resistance offered by an insulation to an impressed DC voltage, tending to produce a leakage current through the insulation.

Insulation Thickness

The wall thickness of the applied insulation.

Interaxial Spacing

1) Center-to-center conductor spacing in paired wire or 2) Center-to-center spacing between conductors in a flat cable.

Interconnecting Cable

The wiring between modules, between units, or the larger portions of a system.


Any undesired electrical signal induced into a conductor by electrical or electromagnetic means.


Void or valley between individual strands in a conductor or between insulated conductors in a multiconductor cable.


Generally the dissociation of an atom or molecule into positive or negative ions or electrons. Restrictively, the state of an insulator whereby it facilitates the passage of current due to the presence of charged particles usually induced artificially.


Acronym for International Power Cable Engineering Association.


Acronym for Insulation Resistance.


Dual-metal combination for thermocouple junctions, used for temperature measurement in oxidizing or reducing atmospheres.


In insulations, the exposure of the material to high energy emissions for the purpose of favorably altering the molecular structure by crosslinking.


Acronym for Instrument Society of America.


Acronym for International Standards Organization.



An outer covering, usually nonmetallic, mainly used for protection against the environment.


Applied over primary insulation, shields, cable components or the cable itself, jackets cover and protect enclosed wires or core against damage, chemical attack, fire and other harmful elements which may be present in the operating environment. Insulating materials include nylon, PVC, CPE, TPE, CSPE, neoprene, hypalon, ethylene-propylene rubber, polyurethane, etc.

JAN Specification

Joint Army-Navy specification (forerunner of present Military Specification).

Jumper Cable

A short flat cable interconnecting two wiring boards or devices.



Constant used to denote insulation resistance.


A polyimide film developed by DuPont which can remain stable in a wide range of temperatures, from −273 to +400 °C (−459 – 752 °F / 0 – 673 K).


1000 circular mils


A numerical prefix denoting 1000.


A term denoting 1000 cycles


A term denoting one thousand cycles


A term denoting one thousand volts.


A term denoting one thousand watts.


Kilovolt (1000 volts).


Kilovolt ampere.




Kilowatt hours (1000 watt hours).


Penwalt trade name for Polyvinylidene Fluoride. Typically used as insulation for wire wrap wire.



A liquid resin or compound applied to textile braid to prevent fraying, moisture absorption, etc.

Laminated Tape

A tape consisting of two or more layers of different materials bonded together.


Local Area Network for Controller Ethernet.


Local Area Networks System (integration of computer & communication). System that wires together all computers and peripherals in an office so they can talk to each other.


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."

Lay Length

A term used in cable manufacturing to denote the distance of advance of one element (conductor) of a group of spirally twisted elements, in one turn measured axially.

Leaching and Non-Leaching

In a leaching wire the plasticizer will migrate when exposed to heat. A non-leaching wire will retain its plasticizer under extreme temperature conditions and remain flexible after baking.

Lead Cured

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


Single conductor wire.

Leakage Current

The undesirable flow of current through or over the surface of an insulation.

Life Cycle

A test to determine the length of time before failure in a controlled, usually accelerated, environment.

Light Source

An object capable of emitting light. In fiber optics, the light source Is normally a LED or a laser.


A flexible bundle of fibers used to transmit light.

Light-Intensity Ratio

Ratio of input light intensity to the output light intensity.

Lightwave Communications

Communications using light to carry the information.

Limits of Error

The maximum deviation (in degrees or percent) of a thermocouple or thermocouple extension wire from standard emf-temperature to be measured.

Litz Wire

Type of cable used in electronics to carry alternating current. Litz wire is designed to reduce the skin effect and proximity effect losses in conductors used at frequencies up to about 1 MHz.


Acronym for Loss Of Coolant Accident, a system malfunction associated with nuclear generation stations.

Local Area Network

A baseband or broadband interactive bi-directional communication systems for information exchange on a common transmission line.

Longitudinal Shield

A tape shield, flat or corrugated, applied longitudinally with the axis of the core being shielded.

Longitudinal Wrap

Tape applied longitudinally with the axis of the core being shielded.

Loop Resistance

The total resistance of two conductors measured round trip from one end.

Loss Factor

The product of the dissipation and dielectric constant of an insulating material.

Low Loss Dielectric

An insulating material that has a relatively low dielectric loss, such as Polyethylene or Teflon.

Low Noise Cable

Cable configuration specially constructed to eliminate spurious electrical disturbances caused by capacitance changes of self-generated noise induced by either physical abuse or adjacent circuitry.

Low Tension

Low voltage, as applied to ignition cable.


Acronym for Low Smoke


A term used to describe a termination, usually crimped or soldered to the conductor, with provision for screwing down to a terminal.


Magnetic Field

The region within which a body or current experiences magnetic forces.

Magnetic Flux

The rate of flow of magnetic energy across or through a surface (real or imaginary).

Magnetic Noise

Caused by change in current level, e.g., AC powerline (creates magnetic field around that cable) this magnetic field causes the magnetic noise.

Marker Tape

A tape run in a cable or wire to designate information such as manufacturers ID.

MC Metal-Clad Cable

NEC type designation for power and control cables enclosed in a smooth metallic sheath, welded and corrugated metallic sheath, or an interlocking tape armour.


One thousand circular mils.


A unit for measuring radiation dosage. Equal to one million rads.


One million ohms.


A measuring device that test for high electrical resistance.

Melt Extrude

To heat a material above its crystalline melt point and extrude it through an orifice.


A group of insulated wires to be cabled with other stranded groups into multiple-membered cable.


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.


Abbreviation for 1000 foot


The unit of conductivity. The reciprocal of an ohm.


Megahertz (one million cycles per second). Formerly mc.


1 microfarad (μF) = one millionth (10−6) of a farad, or 1000000 pF, or 1000 nF.


Also called micrometer; the millionth part of a meter.


Noise is a system caused by mechanical vibration of components within the system.


A short (usually less than 30 cm.) electrical wave.


A unit used in measured diameter of a wire or thickness of insulation over a conductor. One one-thousandth of an inch. (.001").


A termination having a different impedance than that for which a circuit or cable is designed.

Modulus of Elasticity

The ration of stress to strain in an elastic material.

Moisture Absorption

The amount of moisture, in percentage, that a material will absorb under specified conditions.

Moisture Resistance

The ability of a material to resist absorbing moisture from the air or when immersed in water.


The basic chemical unit used in building a polymer.


Acronym for Mine Power Feeder cable.


Acronym for Mine Safety and Health Administration, U.S. Dept. of Labor. Establishes standards and safety requirements for mines. "MSHA" may be printed on cables that have been accepted for listing as flame-resistant.


Thermoplastic-insulated machine tool wire. 90C to 105C, 600V.


More than one conductor within a single cable complex.


More than one conductor within a single cable .

Mutual Capacitance

Capacitance between two conductors when all other conductors including ground are connected together and then regarded as an ignored ground.

Mutual Inductance

The ratio of voltage induced in one conductor to the time rate of current change in the separate conductor causing this induction.


Radio hookup wire with polyvinyl insulation and plain or nylon jacket, braid, or shield. 1000V.


DuPont trademark for a polyester material used in the form of a tape.



Acronym for National Bureau of Fire Underwriters.


Acronym for National Bureau of Standards.


A consensus standard published by the National Fire Protection Association (NFPA) and incorporated in OSHA regulations.


Acronym for National Electrical Manufacturers Association.


Approval agency of Norway.


Neoprene is a polychloroprene and is a thermosetting compound. It is flexible, has good oil, ozone, heat and weather resistance, and specified for outdoor applications due to its weather, sunlight and cold temperature properties. It will not support combustion and resists abrasion and cutting.


National Fire Protection Association.


Non-metallic sheathed cable, braid or plastic covered. For dry use, 60°C.


Non-metallic sheathed cable, plastic covered. For dry use, 90°C.


Non-metallic sheathed cable, plastic or neoprene covered. Wet or dry use, 60°C, and corrosive applications.


Unwanted and/or unintelligible signals picked up on a cable circuit.

Nominal O.D.

The desired diameter for a cable that is established within a +/- tolerance.


Type of PVC jacket material whose plasticizer will not migrate into the dielectric of a coaxial cable and thus avoids contaminating and destroying the dielectric.

Non-Contaminating PVC

A polyvinylchloride formulation, which does not produce electrical contamination through plasticizer migration.


A group of polyamide polymers which are used for wire and cable jacketings.



Outer Diameter.


Acronym for Original Equipment Manufacturer.


Conductor displaced within the cross-section of its insulation.


Percentage of a specified gas released during the combustion of insulation or jacketing material.


Acronym for Oxygen-Free High Conductivity copper. OFHC constains no residual deoxidant, 99.95% minimum copper content and an average annealed conductivity of 101%.


Unit of resistance such that a constant current of one ampere produces a force of one volt.


A unit of weight resistivity expressing the resistance of a wire one pound in weight and one mile in length

Oil Aging

Cable aged in an accelerated manner by placement in an oil bath and heated to a pre-set temperature for a stated time.

Oil-Filled Cable

A self-contained pressure cable in which the pressure medium is low viscosity oil having access to the insulation.


Not permitting the passage of light.

Optical Communication Cable

Fiber with a protective jacket around it.

Optical Conductors

Materials which offer a low optical attenuation to transmission of light energy.

Optical Waveguide

A fiber used for optical communications. Analogous to a waveguide used for microwave communications.


Acronym for Occupational Safety and Health Act. Specifically the Williams- Steiger law passed in 1970 covering all factors relating to safety in places of employment.

OSHA Occupational Safety and Health Act 1970

Administered by U.S. Dept. of Labor which establishes Standards and safety requirements which all businesses must meet.


The dissipation of gas from a dielectric evidencing decomposition.


Approval agency of West Germany; Oesterreichischer Verband fur Elektrotechnik.

Overall Diameter

Finished diameter over wire and cable.


Individual strands of tin copper stranded together and then covered with a tin coating.

Overcoated Copper

Overcoated copper is composed of tinned copper strands twisted together followed by an overall tin coating. Same advantages as Prefused or Prebond copper. Acceptable under UL and CSA; not acceptable under MIL specifications.


The current which causes an excessive temperature rise in a conductor.


The amount the trailing edge laps over the leading edge of a tape wrap.

Oxygen Index

Percentage of oxygen necessary to support combustion of a specified material.


A highly active form of oxygen produced by the passage of electric discharges or sparks through air or oxygen.


Packing Fraction

The ratio of active cross-sectional area of fiber core, or cores, to the total end surface of the fiber or fiber bundle.


Two insulated wires of a single circuit associated together.


The union of two insulated single conductors through twisting.


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

Parallel Cable

Two insulated conductors side-by-side in a cable.


An air core (unfilled) direct burial telephone cable used in area subject to rodent attack. It consists of an unfilled cable core, corrugated aluminum shield, corrugated steel tape, flooding compound and polyethylene jacket.

Peak Voltage

The maximum instantaneous voltage.

Percent Conductivity

Conductivity of a material expressed as a percentage of that of copper.


The uniformly spaced variations in the insulation diameter of a transmission cable that result in reflections of a signal, when its wavelength or a multiple thereof is equal to the distance between two diameter variations.


Measure of the resistance that is encountered when forming an electric field in a medium.


A particular stage or point of advancement in an electrical cycle. The fractional part of the period through which the time has advanced measured from some arbitrary point usually expressed in electrical degrees where 360° represents one cycle.

Phase Shift

A change in phase of a voltage or current after passing through a circuit or cable.


Distance between two adjacent crossover points of braid filaments. The measurement in picks per inch indicates the degree of coverage.

Pick Per Inch

Number of weft threads per inch of woven fabric or braiding.


Pitch, otherwise known as conductor twist or center-to center distance, may be short or long. A short pitch will not flare out as readily as a long pitch conductor. When a lead wire is cut on automatic equipment, and terminated separately, a flared conductor can cause extra labor charges. Today, most automatic cutting equipment strips the insulation off the conductor and applies a terminal in one operation. In this case, the longer pitch conductor is satisfactory.

Pitch Diameter

Diameter of a circle passing through the center of the conductors in any layer of a multiconductor cable.

Planetary Cabler

A cabler capable of laying down any number of shielded, overbraided, or jacketed singles, pairs, called groups, or any combination of them in sequence.

Planetary Twister

A twisting machine whose payoff spools are mounted in rotating cradles that hold the axis of the spool in a fixed direction as the spools are revolved so the wire will not kink as it is twisted.

Plastic Deformation

Change in dimensions under load that is not recovered when the load is removed.


A chemical agent added to plastics to make them softer and more pliable.


The air return path of a central-air handling system, either ductwork or open space over a dropped ceiling.

Plenum Cable

Cable approved by Underwriters Laboratories for installation in plenums without the need for conduit.


NEC type designation for Power- Limited Tray Cable for use in class 2 or 3 Power-Limited circuits; instrumentation supervisory control, and thermocouple extension.


(fiber optic) Act of smoothing ends of fibers to an optically smooth finish, generally using abrasives.


Polyethylene terephthalate which is used extensively in the production of a high strength moisture resistant film used as a cable core wrap.


A thermoplastic material having the chemical identity of polymerized ethylene.


A substance made of many repeating chemical units or molecules. The term polymer is often used in place of plastic, rubber, or elastomer.


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


A thermoplastic polymer of propylene.


Polyurethane has exceptional resistance to oil, radiation, fungus, oxidation and ozone. It is unusually tough, has higher tensile strength and elongation, more abrasion resistance and better low temperature flexibility than neoprene. Its major disadvantage, however, is poor resistance to steam, high temperatures and acids. Polyurethane has outstanding "memory" properties, making it an ideal jacket material for retractile cords. Since it is an expensive material, it is only specified when other jacket materials will not satisfy the requirements of the application.

Polyvinyl Chloride (PVC)

Polyvinyl Chloride is a common thermoplastic compound.


Multiple air voids in an insulation jacket wall.


The sealing of a cable termination or other component with a liquid which thermosets into an elastomer.

Power Cables

Cables of various sizes, construction, and insulation, single or multi-conductor, designed to distribute primary power to various types of equipment.

Power Factor

The ratio of resistance to impedance. The ratio of the actual power of an alternating current to apparent power. Mathematically, the cosine of an angle between the voltage applied and the current resulting.


Portable Power Elastomer. Same as Type W except is a thermoplastic elastomer insulation and jacket whereas Type W is all thermoset.


Stranded wire which has been fused, topcoat tinned, or overcoat tinned.

Prebond Copper

Prebond Heavy tin coated individual wires stranded then bonded by resistance heat.

Prefused Copper

Prefused copper (otherwise known as prebond copper) is composed of twisted strands of heavy tinned copper fused along its entire length by heating. Prefused copper gives the characteristics of a solid conductor, but because it is comprised of individual strands it will not work-harden or break when continually flexed. Acceptable under UL and CSA; not generally acceptable under most Mil-W-16878 types.

Primary Insulation

The first layer of nonconductive material applied over a conductor, whose prime function is to act as electrical insulation.

Propagation Delay

Time required for a signal to pass from the input to the output of a device.

Propagation Time

Time required for an electrical wave to travel between two points on a transmission line.


Acronym for Pound per Square Inch.


Acronym for Polytetrafluoroethylene.

Pulling Eye

A device fastened to a cable to which a hook may be attached in order to pull the cable into or from a duct.


A current or voltage which changes abruptly from one value to another and back to the original value in a finite length of time. Used to describe one particular variation in a series of wave motions.

Pulse Cable

A type of coaxial cable constructed to transmit repeated high voltage pulses without degradation.


PVC, or polyvinyl chloride, is a thermoplastic material composed of polymers of vinyl chloride which may be rigid or elastomeric, depending on specific formulation. Used for general-purpose applications at temperatures up to 105°C.


Polyvinylidene fluoride (Kynar).


pyrometer is a non-contacting device that intercepts and measures thermal radiation, a process known as pyrometry.



Acronym for Qualified Parts List.


A four conductor cable.


Three-bay machines which can twist four wires together and cable braided and shielded wires with varying lay lengths.



The unit of radiation dose which is absorbed, equal to 100 ergs/gram.

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.


Acronym for Rural Electrification Administration.


The opposition offered to the flow of alternating current by inductance or capacitance of a component or circuit.

Recovered Edge

Edge of a flat cable or conductor from which measurements are made.

Reference Junction

The junction of a thermocouple which is at a known reference temperature. Also known as the "cold" junction, it is usually located at the emf measuring device.

Reflection Loss

The part of 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.

Register Ton

The register ton is a unit of volume used for the cargo capacity of a ship, defined as 100 cubic feet (2.832 m 3).


Alignment of one object with relation to another. Also called Register.


A material used to reinforce, strengthen or give dimensional stability to another material.


An organic substance of natural or synthetic origin characterized by being polymeric in structure and predominantly amorphous. Most resins, though not all, are of high molecular weight and consist of long chain or network molecular structure.


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 Cable

A cable that returns by its own stored energy from an extended condition to its original contracted form.


Acronym for Radio Frequency Interference.


Acronym for Radio Government, Universal. RG is the military designation for coaxial cable and U stands for "general utility."


Rubber-Insulated, heat resistant building wire. 90C.


Rubber-insulated building wire, heat and moisture-resistant. 75C dry or wet.

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.

Ringing Out

The process of locating or identifying specific conductive paths by means of passing current through selected conductors.

Rise Time

The time required for the initially zero potential existing on a transmission line (which is terminated in its characteristics impedance) to change from 10% to 90% of its full DC value after a DC potential source is instantaneously applied.


Acronym for Root Mean Square.

Rockwell Hardness

A test for determining hardness in which a hardened steel ball or diamond point is pressed into the material under test.


The amount of radiation that will produce on electrostatic unit of ion per cubic centimeter volume.

Rope Lay Conductor

A conductor composed of a central core surrounded by one or more layers of helically laid groups of wire.

Rope Strand

A conductor composed of a center group of twisted strands surrounded by layers of twisted strands.

Rope Stranding

Rope Stranding is composed of cabled groups of any of the following stranded members: bunched, true concentric, compressed, unidirectional concentric, unilay, equilay

Round Conductor

A conductor whose cross section is substantially circular.


DuPont’s trade name for their flame-retardant polyethylene insulating material.


In the breaking strength or tensile strength tests, the point at which the material physically comes apart, as opposed to elongation, yield strength, etc.



Heavy duty, rubber-insulated portable cord. Stranded copper conductors with separator and individual rubber insulation. Two or more color coded conductors cabled with filler, wrapped with separator and rubber jacketed overall. 600V.


Acronym for Society of Automotive Engineers.


Conductor type designation for conductors with silicone insulation and glass braid (formerly Asbestos), for use in dry locations.


Rubber co-polymer of styrene and butadiene.


Service drop cable. Two code, rubber insulated conductors, tape, laid parallel with neutral conductor concentric thereover. Tape and braid overall. Also round construction


Small diameter multi-conductor control cable with neoprene jacket and nylon sheath over polyethylene insulation.


Above ground service entrance cable, not protected against mechanical abuse. Flame-retardant, moisture-resistant covering. Overall neoprene sheath, 60°C-75°C.

Secondary Insulation

A high resistance dielectric material which is placed over primary insulation to protect it from abrasion.

Selenium Cure

Process used to cure neoprene and rubber jacketed wires and cables.


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 factory-assembled with a messenger which supports the assemblage and which may or may not form a part of the electrical circuit.

Self-Supporting Cable

Any assemblage of conductors which incorporates a steel rope of steel sheath for added tensile strength, thus enabling it to be suspended between widely spaced supports.

Semi-Conducting Tape

A tape of such resistance that when applied between two elements of a cable, the adjacent surfaces of the two elements will maintain substantially the same potential.


A material that has a resistance characteristic between that of insulators and conductors.

Semi-Rigid PVC

A hard semi-flexible polyvinylchloride compound with low plasticizer content.


Approval agency for Sweden.


Service cord with Elastomer jacket, oil resistant jacket, oil resistant insulation and weather resistant. Same as SEOW but has oil resistant singles too. SEOOW meets CSA approval for outdoor use as STOW. 600V


Service cord with Elastomer jacket, oil resistant jacket and weather resistant. SEOW meets CSA approval for outdoor use as STOW. Features a Thermo-plastic Elastomer (TPE) jacket and insulation and is water resistant. 600V


A layer of insulating material such as textile, paper, polyester, etc. Used to improve stripping qualities, flexibility, mechanical or electrical protection to the components.


Service round entrance cable (Type SE, Style R).

Series Resistance

Any sum of resistances installed in sequential order within one circuit.


A filament or group of filaments such as fibers or wires, wound around a central core.

Served Wire Armor

Spiral wrap of soft galvanized steel wires wrapped around a cable to afford mechanical protection and increase the cable pulling tension characteristics.


A wrapping applied over the core of a cable. Servings may be in the form of filaments, fibers, yarn, wires, tape, etc.


Service Entrance Cable (type SE, style U). (Unarmored).


Silicone Rubber insulated equipment wire (CSA).


Silicone Rubber insulated equipment wire (CSA).


Silicone rubber insulated fixture wire, solid or 7 strand conductor. 200C.


Same as SF, except flexible stranding. 150C.


Portable mine power cable, three or four individually shielded conductors, with grounding conductors. 5000V-8000V-15000V.


The outer covering or jacket of a multiconductor cable.


A metallic layer placed around a conductor or group of conductors to prevent electrostatic interference between the enclosed wires and external fields.

Shield Coverage

The physical area of a cable that is actually covered by the shielding material and is expressed in percent.

Shield Effectiveness

The relative ability of a shield to screen out undesirable signals.

Shield Percentage

The physical area of a circuit or cable actually covered by shielding material, expressed in percent.

Shock Test

A test to determine the ability of a cable to withstand a violent physical concussion such as might occur during handling or use.

Shore Hardness

An instrument measure of the surface hardness of an insulating or jacket material.


Specific inductive capacitance. Same as Dielectric Constant.


A current used to convey information, either digital, analog, audio or video.

Signal Cable

A cable designed to carry current of usually less than one ampere per conductor.


Metallic chemical element with the chemical symbol Ag and atomic number 47


Fusion of a spirally applied tape wrap jacket by the use of high heat to a homogeneous continuum. Usually employed for fluorocarbon, nonextrudable materials.


Indicates single conductor having synthetic thermosetting insulation of heat- resistant, moisture-resistant, flame-retarding grade. Also made with chemically cross linked polyethylene insulation. Used for switchboard wiring only, 90C.


Junior hard service, rubber-insulated pendant or portable cord. Same construction as type S, but 300V. Jacket thickness different.


Same as SJ, but neoprene, oil-resistant compound outer jacket. 300V, 60C.


Same as type SJO, except oil resistant insulation and oil and weather resistant jacket.


Junior hard service thermoplastic or rubber-insulated conductors with overall thermoplastic jacket. 300V, 60C to 105C.


Same as SJT but oil-resistant thermoplastic outer jacket. 60C.

Skin Effect

The tendency of alternating current, as its frequency increases, to travel only on the surface of a conductor.


A cable designed for use in hazardous locations consisting of insulated conductors in an extruded nonmetallic jacket which is then covered with an overlapping spiral metal tape and wire shield and jacketed with an extruded moisture, flame, oil, corrosion, fungus and sunlight-resistant nonmetallic material.


Hard service cord, same construction as type S except oil-resistant neoprene jacket. 600V, 60C to 90C.

Solid Conductor

A single unit not divided into parts.


Service cord with oil resistant jacket, oil resistant insulation and weather resistant. Also is water resistant. 600V


Water resistant neoprene jacketed portable cord (UL/CSA).


All rubber, parallel jacketed, two- conductor light duty cord for pendant or portable use in damp locations. 300V.


Same as SP-1, but heavier construction, with or without third conductor for grounding purposes. 300V.


Same as SP-2, but heavier construction for refrigerators or room air conditioners. 300V.


Distance between the closest edges to two adjacent conductors.


In flat cables, the distance from the reference edge of the first conductor to the reference edge of the last conductor (in cables having flat conductors), or the distance between the centers of the first and last conductors (in cables having round conductors), expressed in inches or centimeters.

Spark Test

A test designed to locate imperfections (usually pin-holes) in the insulation of a wire or cable by application of a voltage for a very short period of time while the wire is being drawn through the electrode field.


Acronym for Submersible Pump Cable.

Specific Gravity

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

Specific Inductive Capacity

Same as dielectric constant.

Spectral Response

The response of a detector (or a system) over different wavelengths.

Spiral Wrap

The helical wrap of a material over a core.


Multiple Shielded Pairs or Triads with overall shield, instrumentation or thermocouple extension cable.


Same as SP-1, except all- thermoplastic. 300V. With or without 3rd conductor for grounding.


Service cord with parallel conductors and Thermoplastic insulation. AWM Style 20288, extra flexible parallel cord for use as internal wiring of appliances or can be woven through links of chains (suspended fixtures). 300V


Same as SP-2, except all- thermoplastic. 300V. With or without 3rd conductor for grounding. Same as SP-2, except all- thermoplastic. 300V. With or without 3rd conductor for grounding.


Same as SP-3, except all- thermoplastic. 300V. With or without 3rd conductor for grounding.


Hard service cord, jacketed, same as type S except all-plastic construction, 600V, 60C to 105C.

Stability Factor

The difference between the percentage power factor at 80 volts/mil and at 40 volts/mil measured on wire immersed in water at 75C for a specified time.

Standing Wave

The stationary pattern of waves produced by two waves of the same frequency traveling in opposite directions on the same transmission line. The existence of voltage and current maxima and minima along a transmission line is a result of reflected energy from an impedance mismatch.

Standing Wave Ratio

A ratio of the maximum amplitude to the minimum amplitude of a standing wave stated in current or voltage amplitudes.

Static Condition

Used to denote the environmental conditions of an installed cable rather than the conditions existing during cable installation.

Step Index Fiber

(fiber optic) A multimode fiber consisting of a core of uniform refractive index, surrounded by cladding of slightly lower refractive index.


Same as ST but with oil-resistant thermoplastic outer jacket. 600V, 60C.


Same as STO but with oil-resistant insulation.


Service cord with oil resistant Thermoplastic jacket and weather resistant. STOW meets CSA approval for outdoor use. Can be water resistant - UL 600V


A single uninsulated wire.

Stranded Conductor

A conductor composed of individual groups of wires twisted together to form an entire unit.


To remove insulation or jacket to expose the conductor.

Strip Force

The force required to remove a small section of insulating material from the conductor it covers.


Service cord with Thermo-plastic, and weather resistant jacket, but not oil resistant. Can be UL water resistant. STW meets CSA approval for outdoor use. 600V

Suggested Working Voltage

AC voltage that can be applied between adjacent conductors.

Surface Resistivity

The resistance of a material between two opposite sides of a unit square of its surface. It is usually expressed in ohms.


A temporary and relatively large increase in the voltage or current in an electric circuit or cable. Also called transient.


DuPont’s trade name for their thermoplastic resin with ionic crosslinks.


Vacuum cleaner cord, two or three conductor, rubber-insulated. Overall rubber jacket. For light duty in damp locations. 300V, 60C.


Same as SV except neoprene jacket. 300V, 60C.


Same as SV except all-plastic construction. With or without third conductor for grounding purposes only. 300V, 60C to 90C.


Same as SV except all-plastic construction. With or without third conductor for grounding purposes only. 300V, 60C to 90C.

Sweep Test

A method to determine the frequency response of a cable by generating an RG voltage whose frequency is varied at a rapid constant rate over a given range.

Switchboard Cable

A cable used within and between the central office main frames and the switchboard.



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.

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.

Tape Insulations

Used as primary insulation, tape insulations include TFE, Kapton, Mica, Polyester, alone or laminated with other materials, etc.

Tape Wrap

A spirally applied tape over an insulated or uninsulated wire.


Acronym for Tinned Copper.

Tear Strength

The force require to initiate or continue a tear in a material under specified conditions.


A DuPont Company trademark for fluorocarbon resins. FEP, PFA and TFE are typical materials.

Teflon FEP

DuPont trade name, Fluorinated ethylene propylene or FEP is a copolymer of hexafluoropropylene and tetrafluoroethylene

Teflon PFA

DuPont trade name, Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene


DuPont trade name for a fluorocarbon material typically used as a wire wrap insulation.

Telemetry Cable

Cable used for transmission of information from instruments to the peripheral recording equipment.

Temperature Coefficient of Resistivity

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

Temperature Rating

The maximum temperature at which an insulating material may be used in continuous operation without loss of its basic properties.

Temperature Ratings

The maximum temperature at which an insulating material may be used in continuous operation without loss of its basic properties.

Temperature Stress

The maximum stress which can be applied to a material at a given temperature without physical deformation.

Tensile Strength

The pull stress required to break a given specimen.

Tensile Stress

A term denoting the greatest longitudinal tensile stress a substance can bear without tearing apart or rupturing.

Tension Member

A member included in a fiber cable to add tensile strength.


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.


Canadian Standards Association type appliance wires. Solid or stranded single conductor, plastic-insulated. 600V, 105C.

Textile Braid

Any braid made from threads of cotton, silk, or synthetic fibers.


Fixture wire, thermoplastic-covered solid or 7 strands with nylon sheath. 60C.

Thermal Aging

Exposure to a thermal condition or programmed series of conditions for predescribed periods of time.

Thermal Rating

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

Thermal Resistance

Change in the electrical resistance of a material when subjected to heat. Resistance to heat flow from conductors to outer surface of insulation or sheath in a wire of cable.

Thermal Resistivity

Thermal resistance of a unit cube of material.

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.


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 the terminal block, connecting head, or protecting tube.

Thermocouple Extension Cable

A cable comprised of one or more twisted thermocouple extension wires under a common sheath.

Thermocouple Extension Wire

A pair of wires of dissimilar alloys having such EMF-temperature characteristics complimenting the thermocouple which is intended to be used, such that when properly connected allows the emf to be faithfully transmitted to the reference junction.

Thermocouple Wire

A pair of wires of dissimilar alloys having emf-temperature characteristics calibrated to high temperature levels than the extension type of thermocouple wire.


A material which softens when heated and becomes firm on cooling.

Thermoplastic Insulation

Jacket compounds (such as PVC, PE, and TPE) that will resoften and distort from their formed shapes by heating above a critical temperature peculiar to the material.


A material which hardens or sets by heat, chemical or radiation cross- linking techniques and which, once set, cannot be resoftened by heating.


Term describing insulation that will resoften or distort from its formed shape by heating until a destructive temperature is reached.


90C, 600 volt, nylon jacketed building wire for dry locations.


Thermoplastic vinyl insulated building wire. Flame-retardant, moisture and heat- resistant. 75C Dry and wet locations.


Same as THW but with nylon jacket overall. 75C.


Same as THWN with 90°C dry, 90°C wet location.

Tin Overcoat

Tinned copper wire, stranded, then coated with pure tin.

Tinned Copper

Tin coating added to copper to aid in soldering and inhibit corrosion.

Tinned Copper Conductors

Tinned copper conductors are typically specified for use in electrical and electronic equipment. Though slightly more expensive than bare copper, they facilitate rapid soldering and the small price differential is more than offset by savings in labor cost.


A type of electrical conductor comprised of a number of tiny threads, each thread having a fine, flat ribbon of copper or other metal closely spiraled about it. Used for small size cables requiring limpness and extra long flex life.

Tinsel Wire

low voltage electrical wire used when maximum mechanical flexibility is required


The transportation of one ton cargo over a distance of one kilometre.


Bare (untinned) copper wire, stranded, then coated with pure tin.

Topcoated Copper

Topcoated copper is the same as overcoated copper with the exception that bare copper strands are used. Acceptable under UL and CSA; not acceptable under MIL specifications.


Acronym for Thermoplastic Elastomer, a thermoplastic rubber which has mechanical characteristics of thermoset rubbers yet is a thermoplastic. They have excellent ozone and chemical resistance, excellent electrical properties and low water absorption. Temperature range is -70°C to 125°C.


A means of identifying polarity.

Transfer Impedance

For a specified cable length, transfer impedance is defined as the ratio of internal longitude in a voltage to external current flow on the cable shield. Transfer impedance is used to determine shield effectiveness against both the ingress and egress of interfering signals.


Transfer of electric energy from one location to another through conductors or by radiation or induction fields.

Transmission Line

A signal-carrying circuit with controlled electrical characteristics used to transmit high-frequency or narrow-pulse signals.

Transmission Loss

The decrease or loss in power during transmission of energy from one point to another. Usually expressed in decibels.


Transmitting rays of light so that objects can be seen through the material.


A cable tray is a unit or assembly of units or sections, and associated fittings, made of noncombustible materials forming a rigid structural system used to support cables.

Tray Cable

A factory-assembled multiconductor or multipair control, signal or power cable specifically approved under the National Electrical Code for installation in trays.

Triaxial Cable

A cable construction having three coincident axes, such as conductor, first shield and second shield all insulated from one another.

Triboelectric Noise

Noise generated in a shielded cable due to variation in capacitance between shielding and conductor as the cable is flexed.


A cable consisting of three insulated single conductors twisted together.


A cable composed of three insulated single conductor cables twisted together.

True Concentric

True Concentric strand construction consists of a central wire surrounded by one or more layers with lay direction reversed for successive layers, with increased length of the lay for each successive layer. Normal direction of lay of the outer layer is left-hand.


A tube of extruded nonsupported plastic or metallic material.

Twin Cable

A cable composed of two separately insulated stranded conductors laid parallel under a common covering.

Twin Coaxial Cable

A single cable consisting of two separate coaxial cables laid adjacent and parallel or twisted together.

Twin Line

A transmission line which has a solid insulating material, in which the two conductors are placed in parallel to each other.


A device for twisting together two conductors.

Twisted Pair

A twisted pair is composed of two small separately insulated wires twisted together without a common covering.

Twisted Triad

Any three individually insulated conductors which are twisted together.



Thermoplastic underground feeder and branch circuit cable.


Underground feeder cable, thermoplastic insulated with conductors rated at 90°C.


Acronym for Ultra High Frequency; 300 to 3,000 Mhz.


Acronym for Underwriters Laboratories, a nonprofit independent organization which operates a listing service for electrical and electronic materials and equipment.

Ultraviolet Degradation

The degradation caused by long time exposure of a material to sunlight or other ultraviolet rays containing radiation.

Unbalanced Circuit

A transmission line in which voltages on the two conductors are unequal with respect to ground; e.g., a coaxial cable.

Unbalanced Line

A line where the voltage on the two conductors are not equal with respect to ground.

Unidirectional Concentric

Unidirectional Concentric strand construction is the same as true concentric with the exception that lay direction is the same in all layers. Normal direction of lay of the outer layer is left-hand.

Unidirectional Concentric Stranding

A stranding where each successive layer has a different lay length, thereby retaining a circular form without migration of strands from one layer to another.

Unidirectional Stranding

A term denoting that in a stranded conductor all layers have the same direction of lay.


Unilay strand construction is the same as true concentric with the exception that lay length is the same in each layer. Normal direction of lay is left-hand.

Unilay Stranding

A bunched construction having 19, 27, 37, or any number of strands which might be found in a concentric stranding.


Acronym for Underground Service Entrance cable, rubber-insulated, neoprene or XLP jacketed.


Same as USE except 90°C wet rating.


Approval agency for France; Union Technique de l’Electricite.



Any void between the insulated conductors of a cable or between a cable core and its covering. See also interstice.


West Germany approval agency.

Velocity of Propagation

The speed of an electrical signal down a length of cable compared to speed in free space expressed as a percent. It is the reciprocal of the square root of the dielectric constant of the cable insulation.

VFD Cables

Variable Frequency Drive cables, VFD, used to connect alternating current variable frequency drives to alternating current variable frequency motors.


Acronym for Very High Frequency, 30 to 300 Mhz.

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.


A unit of electrical pressure. One volt is the amount of pressure that will cause one ampere of current in one ohm of resistance.


Electrical potential or electromotive force expressed in volts.

Voltage Drop

A term expressing the amount of voltage loss from original input in a conductor of given size and length.

Voltage Levels

Power-Limited 0-300 volts, Low Voltage 600-2000 volts, Medium Voltage 5000-69000 volts.

Voltage Rating

The highest voltage that may be continuously applied to a wire in conformance with standards or specifications.

Voltage Standing Wave Radio

The ratio of the maximum effective voltage to the minimum effective voltage measured along the length of mis-matched radio frequency transmission line.

Volume Resistivity

The electrical resistance between opposite faces of a 1 cm. cube of insulating material, commonly expressed in ohms/centimeter.


An irreversible process during which a rubber or polymeric compound through a change in its chemical structure (for example, crosslinking) become thermoset.


A flammability rating established by Underwriters Laboratories for wires and cables pass a specially designated vertical flame test, formerly designated FR-1. Multiconductor flat or round portable power cables without grounding conductor.



Without ground.

Wall Thickness

The thickness of the applied insulation or jacket.

Water Absorption

Water by percent weight absorbed by a material after a given immersion period.

Water Absorption Test

A method to determine the water absorbed through an insulating material after a given water immersion period.

Waterblocked Cable

A cable constructed with no internal voids in order to allow no longitudinal water passage under a given pressure.


A unit of electrical power. One watt is equivalent to the power represented by one ampere of current under a pressure of one volt in a DC circuit.


The distance, measured in the direction of propagation, of a repetitive electrical pulse or waveform between two successive points.

WC 70

Same as ICEA S-95-658-1999.


Same as ICEA S68-516.


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


A single conductor, typically with a covering of insulation.

Wire Gauge

A measure of the diameter or size of wires. The sizes are expressed by numbers.



High temperature (90C) chemically cross-linked polyethylene jacketed small diameter building wire.


600V cross-linked polyethylene (XLP) insulated building wire. 90ºC dry, 90°C wet.


Acronym for Cross-Linked Polyethylene.


Acronym for Cross-Linked Polyethylene.


Yield Strength

The minimum stress at which a material will start to physically deform without further increase in load.



NEC conductor type designation for conductors with ETFE insulation for use in dry locations.


NEC conductor type designation for conductors with ETFE insulation for use in wet or dry locations.


DuPont’s trade name for nylon resins.