Wire and cable Glossary

[Andrew caldwell Martin]

Glossary

At Metsec we want to make sure you have all the information you need to make an informed buying decision. The terms below are all cable related and may help when comparing specifications or working out what characteristics are important to you in a product.

A

AAR

Association of American Railroads.

Abrasion Resistance

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

Absorption

Alternating Current. Current in which the charge-flow periodically reverses and is represented by 1 = 1º cos (2f + f) where, 1 is the current, 1º is the amplitude, (f) the frequency, (f) the phase angle.

AC Alternating Current (AC)

Current in which the charge-flow periodically reverses.

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

A test in which voltage, temperature, etc., are increased above normal operating values to obtain observable deterioration in a relatively short period of time. The plotted results give expected service life under normal conditions.

Accelerator

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

Acceptance Angle

The half-angle of the cone within which all incident light is totally internally reflected by the fiber core. For graded index fibers, acceptance angle is a function of position on the entrance face of the core.

Accordian

(1) A retractile cable with a series of equally-spaced transverse folds. (2) A connector contact with a Z shaped flat spring to permit high deflection without overstress.

ACM

Aluminum conductor material.

Activator

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.

Adapter

A device that enables any or all of the following a) different sizes or types of plugs to mate with one another or to fit into a telecommunications outlet/connector; b) the rearrangement of leads; c) large cables with numerous wires to fan out into smalle.

Adapter-Fiber

A mechanical media termination device designed to align and join fiber optic connectors. Often referred to as a coupling, bulkhead, or interconnect sleeve.

Adhesion

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

Adhesive Bonded

Cables bonded by adding an adhesive coating to the surface of the cable components, then joining and curing the adhesive to form a cable. See Bonded Cables.

Adjacent Conductor

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

Administration

The method for labeling, identification, documentation and usage needed to implement moves, additions and changes of the telecommunications infrastructure.

Admittance

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

AEIC

Association of Edison Illuminating Companies.

Aerial Cable

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

Aging

The change in properties of a material with time under specific conditions.

AIA

Aluminum Interlocked Armor.

Air Core

A telephone outside plant cable construction for aerial and duct installation in which the insulated conductors in the cable core are surrounded by air.

Air Spaced Coaxial Cable

One in which air is essentially the dielectric material. A spirally wound synthetic filament, beads, or braided filaments may be used to center the conductor.

Air-Handling Plenum

A designated area, closed or open, used for environmental air.

Alligator Clip

A mechanical device shaped like alligator jaws used as a temporary connection on the sod of interconnections wire.

Alloy

A combination of two or more metals to form a new or different metal having specific or desirable qualities.

All-Rubber Cable

A cable in which all interstices between conductors are filled with rubber compound.

ALPETH

Telephone cable sheath employing a corrugated aluminum shield and an outer polyethylene jacket.

ALS

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

Alternating Current (AC)

Electric current that continually reverses its direction. It is expressed in cycles per second (hertz or Hz).

Alternating Voltage

The voltage developed a cross a resistance or impedance through which alternating current is flowing.

Aluminum Conductor

An aluminum wire or group of wires not suitably insulated to carry electrical current.

Aluminum-Steel Conductor

A composite conductor made up of a combination of aluminum and steel wires.

ALVYN

A cable sheath consisting of a coated corrugated aluminum (AL) shield and an outer polyvinyl chloride (VYN) jacket.

Ambient Temperature

The temperature of the medium surrounding an object. Generally a lower temperature than the temperature at which the cable is operating.

American Wire Gauge (AWG)

The standard system used for designating wire diameter. The lower the AWG number, the larger the diameter. Also called the Brown and Sharpe (B&S) wire gauges.

Ampacity

The maximum current an insulated wire or cable can safely carry without exceeding either the insulation or jacket material limitations. (Same as Current Carrying Capacity.)

Ampere (AMP)

The unit of cur rent. One ampere is 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 poi.

Amplitude

Height of a waveform that represents signal strength.

Analog

A signaling format that uses continuous physical variables such as voltage amplitude or frequency variations to transmit information.

Analog Signal

A signal in which the intelligence is represented by continuously varying quantities.

Angle of Incidence

The angle between an incident ray and the normal to a reflecting surface.

Angle of Refraction

Angle formed between a refracted ray and the normal to the surface. This angle lies in a common plane with the angle of incidence.

Anneal (Soften)

To subject to high heat with subsequent cooling. When annealing copper, the act of softening the metal by means of heat to render it less brittle.

Annular Conductor

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

Annunciator

A signaling device, usually electrically operated, that gives an audible or visual signal (or both) when energized.

Anode

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 electro-chemical cell.

ANSI

The American National Standards Institute.

Anti-Oxidant

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

Anti-Ozonant

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

Appliance Wire and Cable

Appliance wiring material is a classification of Underwriters' Laboratories, Inc., covering insulated wire and cable intended for internal wiring of appliances and equipment. Each construction satisfies the requirements for use in particular applications.

Aramid Yarn

Strength elements that provide tensile strength, support, and additional protection of fiber bundles. It is commonly referred to as Kevlar (a DuPont trademark).

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.

Armor

A braid or wrapping of metal, usually steel or aluminum, used for additional mechanical protection in harsh environments.

ASA

The American Standards Association, former name of ANSI.

ASME

The American Society of Mechanical Engineers.

ASP

A cable sheath consisting of a corrugated aluminum (A) shield, corrugated steel (S) shield, flooding compound and an outer polyethylene (P) jacket.

ASTA

United Kingdom approval agency.

ASTM

Abbreviation for the American Society for Testing and Materials, a non-profit industry-wide organization which publishes standards, methods of test, recommended practices, definitions and other related materials.

Attenuation

The decrease in magnitude of the power of a signal in transmission between points. Attenuation is usually measured in decibels per unit length at a specific frequency.

Attenuation to Crosstalk Ratio (ACR)

The difference between attenuation and crosstalk, measured in dB, at a given frequency. Important characteristic in networking transmission to assure that signal sent down a twisted pair is stronger at the receiving end, after being attenuated, than are a

Audio Frequency

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

AWG

Abbreviation for American Wire Gauge.
   
B

B & S Gauge

The same as American Wire Gauge (AWG).

Backbone

The main portion of network cabling, connecting equipment rooms or communications closets. These cables often have the largest number of fibers and/or the longest continuous cable runs.

Backbone Cable or Wire

Cable or wire found in the backbone, see Backbone.

Backscattering

The scattering of light in a direction opposite to the original one.

Balanced Circuit

A circuit so arranged 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 cable having two identical conductors which carry voltages opposite in polarity and equal in magnitude with respect to ground.

Balun

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

Band Marking

Repeated circumferential bands applied to a conductor at regular intervals for identification.

Banded Cable

Two or more cables banded together by stainless steel strapping.

Bandmarking

A circumferential color band applied to an insulated conductor at regular intervals for identification.

Bandwidth

(1) The difference between the upper and lower limits of a given band of frequencies. Expressed in Hertz. (2) A measure of the maximum frequency range over which light intensity exiting a waveguide one kilometer in length can be varied before the attenua.

Bank Wire

An insulated wire used for the interconnection of selector switches in automatic telephone exchanges.

Bare Conductor

A conductor not covered with insulating material.

Barrel-Packed

Method of coiling into a fiber drum for shipment.

Baseband

In data transmission, the use of a dedicated end-to-end connection to carry a single channel only.

Baseband Signaling

Transmission of a digital or analog signal at its original frequencies, i.e., a signal in its original form, not changed by modulation.

Basic Conductor Load

The limiting conductor-load per unit length assumed for the purposes of design.

Battery Cable

A single conductor cable, insulated or uninsulated, used for carrying current from batteries to the point power is needed.

BCF

Abbreviation for billion conductor feet. A quantity derived by multiplying the number of conductors in a cable by the amount of cable. Usually used to indicate plant capacity or an annual requirement.

Beaded Coax

Coaxial cable with a dielectric consisting of beads made of various materials.

Bedding

A layer of material applied to a cable immediately below the armoring.

Bell Wire

Insulated copper wire for making doorbell and thermostat connections in homes.

Belt

Number of layers of insulation on a conductor, or number of layers of jacket on a cable.

Belted-Type Cable

Multiple conductor cable having a layer of insulation over the assembled insulated conductors.

Bend Loss

A form of increased attenuation caused by (a) having an optical fiber curved around a restrictive radius of curvature or (b) microbends caused by minute distortions in the fiber imposed by externally induced forces.

Bend Radius

Radius of curvature that a fiber optic or metallic cable can bend without any adverse effects.

Bifilar

A winding made non-inductive by winding together (as one wire) two wires carrying current in opposite directions.

Billion Conductor Feet (BCF)

A quantity derived by multiplying the number of conductors in a cable by the amount of cable. Usually used to indicate plant capacity or an annual requirement.

Bimetallic Wire

A wire formed of two different metals joined together (not alloyed). It can include wire with a steel core clad wire, or plated or coated wire.

Binder

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

Binding Post

A device for clamping or holding electrical conductors in a rigid position.

Bit

One binary (0 or 1) digit.

Bit Rate

The rate at which binary or code information is transmitted over a communicating channel. Measured in bits per second.

Blown Jacket

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

Bond Strength

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

Bondable Wire

An insulated wire treated to facilitate adherence to materials such as potting compounds. Also, magnet wires used in making coils when bonding the turns together is desired.

Bonded Cable

Cable consisting of pre-insulated conductors or multi-conductor components laid-in parallel and bonded into a flat cable. See Solvent-Bonded, Adhesive-Bonded and Film Bonded.

Bonded Construction

An insulation construction in which the glass braid and nylon jacket a re bonded together.

Bonded Flat Cable

Flat cable consisting of individually insulated conductors lying parallel and bonded together: application in electronics, telecommunications or computers.

Bonding

The permanent joining of metallic parts to form an electrically conductive path that will assure electrical continuity and the capacity to conduct safely any current likely to be imposed on it.

Bonding Conductor

An insulated or uninsulated conductor forming part of the cable assembly which is used for the purpose of connecting non-current carrying parts of electrical equipment to a system grounding conductor.

Booster

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

Boot

(1) Protective covering over a cable, wire or connector in addition to the normal jacketing or insulation. (2) A form placed around wire termination of a multiple-contact connector to contain the liquid potting compound before it hardens.

BPF

Billion paired feet.

Braid

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 in the axis of the cable being shielded.

Braid Carrier

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

Braid Ends

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

Braiding Machine

Machine used to apply braids to wire and cable and to produce braided sleeving and braids for tying or lacing purposes. Braiding machines are identified by the number of carriers.

Brake Wire

Wire used in mobile-home, travel and truck trailers to supply current to the electrical braking system.

Breakdown (Puncture)

A disruptive discharge through the insulation.

Breakdown of Insulation

Failure of an insulation resulting in a flow of current through the insulation. It may be caused by the application of too high voltage or by defects or decay.

Breakdown Voltage

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

Breakout

The point at which a conductor or group of conductors breaks out from a multi-conductor cable to complete circuits at various points along the main cable.

Breakout Cable

Multi-fiber cable constructed in the tight buffered design with individually jacketed fibers. Designed for ease of connectorization and rugged applications for intra- or inter-building requirements.

Bridge

A device used to expand a local area network by forwarding frames between data link layers.

Bridged Tap

The multiple appearances of the same cable pair at several distribution points.

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.

Broadband

In data transmission, the use of a carrier signal, rather than direct modulation, to carry several simultaneous channels.

Buffer

Coating used to protect optical fiber from physical damage. Types include tight buffer (indoor) or loose tube (outdoor).

Buffing Stripper

A motorized device for removing flat cable insulation by means of buffing wheels that melt the insulation and brush it away from the conductors. Also called Abrasion Stripper.

Building Entrance Area

A space in which the joining of inter- or intra-building telecommunications backbone facilities takes place. An entrance room may also serve as an equipment room.

Building Wire

Wire used for light and power in permanent installations utilizing 600 volts or less. Usually in an enclosure and which will not be exposed to outdoor environments.

Bunch Strand

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

Bunched Stranding

A group of strands twisted together in a random manner and the same direction without regard to geometric arrangement of specific strands.

Buncher

A machine that twists wires together in random arrangement.

Bundle

Several individual fibers contained within a single jacket or buffer tube. Also a group of buffered fibers distinguished in some fashion from another group in the same cable core.

Buried Cable

A cable installed directly in the earth without use of underground round conduit. Also called Direct Burial Cable.

Buried Distribution and Service Wires

Telephone wires which are designed to provide buried service extensions from distribution cables to the subscriber's protector.

Bus

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

Bushing

A mechanical device used as a lining for an opening to prevent abrasion to wire and cable.

Butt

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

Butt Splice

A splice where 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 an edge-to-edge condition.

Butyl Rubber

A synthetic rubber with good insulating properties (i.e. low voltage cords).

Byte

Typically a group of eight binary digits.
   
C

C.S.A.

An abbreviation for the Canadian Standard's Association. (The Canadian counterpart of Underwriters' Laboratories.)

Cable

A stranded conductor with or without insulation and other coverings (single-conductor cable) or a combination of conductors (multiple-conductor cable). In fiber optics, a jacketed fiber or jacketed bundle in a form which can be terminated.

Cable Assembly

Typically, the cable and associated connectors that is ready to install.

Cable Bend Radius

The radius that a fiber can be bent before risking increased attenuation or fiber breaks.

Cable Clamp

A device used to give mechanical support to the wire bundle or cable at the rear of a plug or receptacle.

Cable Clamp Adapter

A mechanical adapter that attaches to the rear of a plug or receptacle to allow the attachment of a cable clamp.

Cable Core

The portion of an insulated cable lying under a protective covering.

Cable Core Binder

A wrapping of tapes or cords around the conductors of a multiple-conductor cable used to hold them together.

Cable Filler

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

Cable Rack

The vertical or horizontal open support (usually made of aluminum or steel) that is attached to a ceiling or wall.

Cable Sheath

The overall protective covering applied to cables.

Cable Tray

A ladder, trough, solid-bottom or channel raceway system intended for, but not limited to, the support of telecommunications media (i.e., cable).

Cable Vulcanizer

Compression molding machine used to repair cable jacketing that has had a part removed for splicing, for adding connectors or other devices or for replacing damaged sections.

Cable, Star Quad

A multi-core radio or television relay cable in which the conductors are arranged in quads and each quad consists of four conductors twisted together, the diagonally opposite conductors constituting a pair circuit. Also known as spiral four cable.

Cable-in-Duct

System for direct burial in which a flexible conduit is extruded over electrical cables for a single pre-assembled unit.

Cabling

A combination of all cables, wire, cords and connecting hardware; (2) Twisting together two or more insulated conductors by machine to form a cable. In fiber optics, a method by which a group or bundle of fibers is mechanically assembled.

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.

Campus

The building and grounds of a complex (i.e. a university, college, industrial park or military establishment).

Canadian Standards Association (CSA)

A non-profit independent organization which operates a listing service for electrical and electronic materials and equipment. The Canadian counterpart of the Underwriters Laboratories.

Capacitance

The ratio of the electrostatic charge on a conductor to the potential difference between the conductors required to maintain that charge. Units expressed in Farads.

Capacitance Unbalance

The inequalities of the capacitances of the wires of a telephone circuit to other wires or to earth which will produce interference. Various forms of unbalance arise according to the circuits concerned in the measurement, hence side-to-side, pair-to-pair

Capacitance Unbalance to Ground

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

Capacitance, Direct

The capacitance measured directly with all other conductors, including shield, short circuited to ground.

Capacitance, Mutual

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

Capacitive Coupling

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

Capacitive Reactance (Xc)

The opposition to alternating current due to the capacitance of the cable or circuit. Measured in ohms.

Capillary Action

The phenomenon of liquid rising in a small interstice due to surface tension.

Carrier

The woven element of a braid consisting of one or more ends (strands) which creates the interlaced effect. Also, a spindle, spool, tube, or bobbin (on a braiding machine) containing yarn or wire, employed as a braid.

CATV

Acronym for Community Antenna Television.

CBO

Rubber insulated Brewery Cord.

CCITT

Abbreviation for Consultative Committee of International Telegraph and Telephone.

CCTV

Acronym for Closed-Circuit Television.

CE Code, CEC

Canadian Electrical Code

CEBEC

Belgium Approval Agency; Comite Electrotechnique Belge Service de la Marque.

CEE

European Standards Agency; International Commission on Rules for the Approval of Electrical Equipment.

Cellular Plastics

Expanded or foam, consists of individual closed cells of inert gas suspended in a plastic medium, resulting in a desirable reduction of the dielectric constant.

CENELEC

European Standards Agency; European Committee for Electrotechnical Norms.

Central Member

A material located in the middle of a cable that provides extra strength and anti-buckling properties.

Central Office

The place where communications common carriers terminate customer lines and locate switching equipment that interconnects those lines.

Certificate of Compliance (C of C)

A written statement; normally generated by a Quality Control Department, which states that the product being shipped meets customer's specifications.

Certified Test Report (CTR)

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

Changing Current

The current produced when a D.C. 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.

Characteristic Impedance

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 standing waves.

Charge

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

Chlorinated Polyethylene (CPE)

A polymerized ethylene resin that has been treated or combined with chlorine or a chlorine compound.

Chlorosulfonated Polyethylene (CSPE)

A rubbery polymer used for insulations and jackets. Manufactured by Dupont under the tradename of Hypalon.

Chromatic Dispersion

Spreading of a light pulse caused by the difference in refractive indices at different lengths.

Cigarette Wrap

Tape insulation wrapped longitudinally instead of spirally over a conductor.

Circuit

A complete path over which electrons can flow from the negative terminals of a voltage source through parts and wires to the positive terminals of the same voltage source. When the continuity of the circuit is broken it is called an open circuit: when con

Circuit Sizes

A popular term for building wire sizes 14 through 10 AWG.

Circular Mil (cmil)

A measurement used for the are a of wire, calculated by squaring the diameter. 1 circular mil = (.001) 2 x 10 6

Cladding

A method of applying a layer of metal over another metal where the junction of the two metals is continuously welded. In fiber optics, a sheathing intimately in contact with the core of a higher refractive index material which serves to provide optical i

Clamping Voltage

Underwriters Laboratories (UL) rates the clamping voltage of surge protectors. The lower the rating, the better the protection.

Clorosulfonated Polyethylene (CSPE)

A rubbery polymer used for insulations and jackets. Manufactured by DuPont under the trade name of Hypalon.

Closed End Splice

An insulated splice in which two or more wires overlap and enter the splice from the same end of the barrel.

Closet, Telecommunications

An enclosed space for housing telecommunications equipment, cable terminations, and cross-connect cabling. The closet is the recognized location of the cross-connect between the backbone and horizontal facilities.

Coating

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.

Coaxial Connector

A connector that has a coaxial construction and is used with coaxial cable.

Coherent Source

A light source which emits a very narrow, unidirectional beam of light of one wavelength (monochromatic).

Coil Effect

The inductive effect exhibited by a spiral-wrapped shield, especially above audio frequencies.

Cold Bend

A laboratory test procedure whereby a sample of wire or cable is wound around a mandrel of a specified size at a specified temperature for a given number of turns at a given rate of speed and examined for defects.

Cold Flow

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

Cold Joint

A soldered joint made with insufficient heat.

Cold Test

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

Cold Work

The hardening and embrittlement of a metal by repeated flexing action.

Color Code

A color system for circuit identification by use of solid colors, tracers, braids, surface printing, etc.

Commercial Building

A building or portion thereof, that is intended for office use.

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 than does a separate axis construction.

Common Carrier

An organization that provides regulated telephone, telegraph, telex and data communications systems.

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 Conductor

Stranded conductor rolled to deform the round wires to fill the normal interstices between the wires in a strand.

Compatibility

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

Composite (Clad) Wire

A wire having a core of one metal with a fused outer shell of different metals.

Composite Cable

A cable containing more than one type or gauge size of conductors (I.e. power and control conductors in one assembly).

Composite Conductor

Two or more strands of different metals assembled and operated in parallel.

Compound

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

Compression Cable

A pipe type cable in which the pressure medium is separated from the insulation by a membrane or sheath.

Concentric

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

Concentric Strand

A strand that consists of a central wire or core surrounded by one or more layers of spirally laid wires.

Concentric Stranded Conductors

Manufactured to ASTM, ICEA, and CSA standards. The most common fixed installation type conductors are : 1) Round-no diameter reduction: 2) Compressed-approximately 3% diameter reduction; 3) Compact-approximately 10% diameter reduction.

Concentric Stranding

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.

Concentricity

In a wire or cable, the measurement of the location of the center of the conductor with respect to the geometric center of the circular insulation.

Concentric-Lay Cable

A concentric-lay conductor, or a multiple-conductor cable composed of a central core surrounded by one or more layers of helically laid insulated conductors.

Conductance

The ability of a conductor to carry and electric charge. The ratio of the current flow to the potential difference causing the flow. The reciprocal of resistance.

Conductivity

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

Conductor

A wire (or combination of wires not insulated from one another) suitable for carrying electric current.

Conductor Shield

An extrusion of black semi-conducting thermoses material over the conductor to provide a smooth interface with the insulation for even distribution of electrical stress.

Conduit (Electrical Raceway)

A rigid or flexible metallic or non-metallic raceway of circular cross section through which wire and cables can be pulled or housed.

Connecting Hardware

A device providing mechanical cable terminations.

Connector

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

Connector Return Loss

Amount of power reflected from the connector to connector interface, typically expressed in decibels.

Contact

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

Contact Inspection Hole

A hole in the cylindrical rear portion of contact used to check the depth to which a wire has been inserted.

Contact Size

The largest size wire which can be used with the specific contact. Also, the diameter of the engagement end of the pin.

Contacts

The parts of a connector which actually carry the electrical current, and 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 rubber-like (thermoset) coating materials. Often referred to as CV.

Contrahelical

Cable spiraling in an opposite direction than the preceding layer within a wire or cable.

Control Cable

A multi-conductor cable made for operation in control or signal circuits.

Controlled Impedance Cable

Package of two or more insulated conductors where impedance measurements betweenrespective conductors are kept essentially constant throughout the entire length.

Copolymer

A compound resulting from the polymerization of two different monomers.

Copper Clad

Steel with a coating of copper welded to it before drawing as opposed to copper-plated. Synonymous with Copperweld.

Copperweld

The trade name of Flexo Wire Division (Copperweld Steel Corp.) for its copper-clad steel conductors.

Cord

A small, very flexible insulated cable constructed to withstand mechanical abuse. (Note: There is no sharp dividing line with respect to size between a cord and a cable, but generally, a cord is considered to be a size No. 10 and smaller )

Cord, Telecommunications

A cable using stranded conductors for flexibility as in distribution cords or line cords. Line cords can also use tinsel conductors.

Cordset

Portable cords fitted with a wiring device at one or both ends.

Core

In cables, a component or assembly of components over which other materials are applied, such as additional components, shield, sheath, or armor. In fiber optics, the transparent glass or plastic section with a high refractive index through which the ligh

Core Eccentricity

Measure of the displacement of the center of the core relative to the cladding center.

Core Ellipticity

Measure of the non-roundness of the core.

Corona

A discharge of electricity which appears around a conductor when the potential gradient at the surface of the conductor exceeds a certain value.

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.

Corrosion

The process or result of a material being eaten or worn away, usually by chemical reaction.

Counterpoise

Bare copper, usually soft drawn, buried around the perimeter of a structure for grounding purposes. When grounding electrical transmission towers - usually running parallel to the overhead lines along the right-of-way.

Coupling Efficiency

Efficiency of optical power transfer between two components.

Coupling Loss

Signal losses due to small differences in numerical aperture, core diameter, core concentricity, and tolerances in splicing connectors when two fibers are aligned. Also known as Splicing Loss and Transfer Loss.

Coupling Ring

A device used on cylindrical connectors to lock plug and receptacle together.

Coverage

The calculated percentage which defines the completeness with which a metal braid covers the underlying surface. The higher percentage of coverage, the greater the protection against external interference.

Covering

Textile braid or jacket of rubber plastics, or other materials applied over wire and cable to provide mechanical protection and identification.

CPE

Chlorinated polyethylene can be used as either a thermoplastic or thermoset. It is a tough chemical and oil-resistant material and makes an excellent jacket for industrial control cable. As a thermoset, it can be used as an oil-resistant cord jacket.

Crazing

The minute cracks on the surface of plastic materials.

Creep

The dimensional change with time of a material under a mechanical load.

Creepage

The conduction of electricity across the surface of a dielectric.

Creepage Path

The path across the surface of a dielectric between two conductors.

Creepage Surface

An insulating surface which provides physical separation as a form of insulation between two electrical conductors of different potential.

Crimp

The act of compressing a connector barrel around a cable in order to make an electrical connection.

Crimp Termination

Connection in which a metal sleeve is secured to a conductor by mechanically crimping the sleeve with pliers, presses or automated crimping machines.

Critical Angle

Smallest angle at which a meridional ray may be totally reflected within a fiber at the core-cladding interface.

Cross-Connect

A facility enabling the termination of cable elements and their interconnection, and/or cross-connection, primarily by means of a patch cord or jumper.

Crosslinked

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

Cross-Sectional Area

The area of the cut surface of an object cut at right angles to the length of the object.

Crosstalk

Undesired electrical currents in conductors caused by electromagnetic or electrostatic coupling from other conductors or from external sources. Also, leakage of optical power from one optical conductor to another.

CSA

Abbreviation for Canadian Standards Association, a non-profit independent organization which operates a listing service for electrical and electronic materials and equipment. The Canadian counterpart of the Underwriters Laboratories.

C-SJ

Same as SJ except extra-flexible conductor.

C-SJO

Same as SJO except extra-flexible conductor.

CSPE

Insulating and jacketing compound based on chlorosulfonated polyethylene. Also known as Hypalon (DuPont registered trademark).

Cure

To change the physical properties of a material by chemical reaction, by the action of heat and catalysts, alone or in combination, with or without pressure.

Curing Cycle

The time, temperature, and pressure required for curing.

Curl

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.

Current

The rate of transfer of electricity. Practical unit is the ampere which re presents the transfer of one coulomb per second. In a simple circuit, current (I) produced by a cell or electromotive force (E) when there is an external resistance (R) and intern

Current Carrying Capacity (Ampacity)

The maximum current an insulated conductor can safely carry without exceeding its insulation and jacket temperature limitations.

Current Penetration

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

Current, Alternating (AC)

An electric current that periodically reverses direction of electron flow. The number of full cycles occurring in a given unit of time (one second) is called the frequency of the current.

Current, Direct (DC)

Electrical current whose electrons flow in one direction only; it may be constant or pulsating as long as their movement is in the same direction.

Customer Premises

Building(s) with grounds and appurtenances (belongings) under the control of the customer.

Cut-Through Resistance

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

CV

Abbreviation for continuous vulcanization.

Cycle

The complete sequence of alternation or reversal of the flow of an alternating electric current. (See Hertz.)
   
D

D.C.

Abbreviation for Direct Current.

Decibel (dB)

A unit to express differences of power level. Used to express power gain in amplifiers or power loss in passive circuits or cables.

Delay Line

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

Demarcation Point

A point where the operational control or ownership changes.

DEMKO

Approval agency of Denmark.

Depth of Crimp

Thickness of the crimped portion of a connector measured between two opposite points on the crimped surface.

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.

Detector

A device that picks up light from fiber and converts the information into an electrical signal.

Device, As Related to a Work Station

An item such as a telephone, personal computer, or graphic or video terminal.

Device, As Related to Protection

A protector, a protector mount, a protector unit or a protectomodule.

Dielectric

1) Any insulating medium which intervenes between two conductors and permits electrostatic attraction and repulsion to take place across it; 2) A material having the property that energy required to establish an electric field is recoverable in whole or

Dielectric Absorption

That property of an imperfect dielectric whereby 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 (SIC).

Dielectric Loss

Power dissipated in an insulating medium as the result of the friction caused by molecular motion when an AC Electric field is applied.

Dielectric Strength

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

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. Sometimes called a "Hi-Pot" test (high potential).

Diffraction

Phenomenon that results when light passes by an opaque edge or through an opening, generating weaker secondary wavefronts. These secondary wavefronts interfere with the primary wavefronts as well as with each other to form various patterns.

Digital

A data format that uses discrete or separate physical levels to contain information.

Digital Signal

A signal in which the data is represented by a series of discrete steps or pulses.

Dip Coating

An insulating coating applied to the conductor by passing the conductor through an applicator containing liquid insulating medium.

Direct Burial Cable

A cable installed directly in the earth.

Direct Capacitance

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

Direct Current (DC)

An electric current which flows in only one direction.

Direct Current Resistance (DCR)

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

Direction of Lay

The lateral direction in which the strands of a conductor run over the top of the cable conductor as they recede from an observer looking along the axis of the conductor or cable. Also applies to twisted cable.

Discrete Wiring

Wire or wires having distinct identity and purpose.

Dispersion

Spread of the signal delay in an optical waveguide. It consists of various components: modal dispersion, material dispersion, and waveguide dispersion. As a result of the dispersion, an optical waveguide acts as a low-pass filter for the transmitted signal.

Disruptive Discharge

A sudden, large increase in current through an insulation medium due to the complete failure of the medium under the electrostatic stress.

Dissipation Factor

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

Distribution Cable

In telecommunications and CATV systems, the transmission cable between the distribution amplifier and the drop wire.

Distribution Frame

A structure with terminations for connecting the permanent cabling of a facility in such a manner that interconnection or cross-connections may be readily made.

Disturbed Conductor

A conductor that receives energy generated by the field of another conductor or an external source such as a transformer.

Drain Wire

The uninsulated wire in contact with an electrostatic shield throughout its length, in an instrumentation or control cable, used to discharge unwanted signals. Also provides a means of terminating laminated shields. Sometimes used to describe the metalli

Draw Feed Stock

Rod or wire that is subsequently drawn to a smaller size.

Drawing

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

Drop Ceiling

A ceiling that creates an area or space between the ceiling material and the structure above the material. Synonym: False Ceiling, Suspended Ceiling.

Drop Wire

A telephone cable, usually consisting of one insulated telephone pair, which is used to connect a subscribers premises to open wire lines on poles.

DRT

Plastic range and dryer cord (CSA).

Dual Coaxial Cable

Two individually insulated conductors laid parallel or twisted and placed within an overall shield and sheath.

Duct

(1) A single enclosed raceway for wires or cables. Also Conduit, Raceway; (2) a single enclosed raceway for wires or cables usually used in soil or concrete, (3) an enclosure in which air is moved. Generally part of the HVAC system of a building.

Ductile

Capable of being drawn out or hammered thin, or of being flexed or bent without failure.

Duplex

Referring to a type of data transmission, either half or full. Half duplex permits only one-way communication. Full duplex allows simultaneous two-way transmission.

Duplex Cable

(1) A cable composed of two insulated single conductor cables twisted together. (2) A cable composed of two fibers typically 62.5/125 mm Multi-Mode, placed in parallel under a thermoplastic sheath.

Duplex Parallel

Typically used in the thermo-couple industry to denote two parallel conductors of dissimilar metals insulated in parallel without twist and jacketed. Commonly applied to thermo-couple grades and extension wires.

Durometer

A measure of hardness.
   
E

E

A symbol for voltage. Usually used to represent direct voltage or the effective (root-mean-square) value of an alternating voltage.

Earth

British terminology for zero reference ground

Eccentricity

Like concentricity, 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.

Eddy Current

Circulating currents induced in conducting materials by varying magnetic fields.

EEMAC

Electrical and Electronic Manufacturers Association of Canada (U.S. counterpart is NEMA).

EFTS

Abbreviation for Electronic Funds Transfer System.

EIA

Abbreviation for Electronic Industries Association.

Elastomer

A rubber or rubber-like material which will stretch repeatedly to 200 percent or more and return rapidly and with force to its approximate original shape.

Electrode

A conductor through which a current enters or leaves a nonmetallic conductor.

Electrolysis

The production of chemical changes by passage of current through an electrolyte.

Electrolytic Tough Pitch

A term describing the method of raw copper preparation to ensure a good physical and electrical grade copper finished product containing less than 1/10 of 1% impurities. (ASTM B5.)

Electromagnetic

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

Electromagnetic Coupling

Energy transfer by means of a varying magnetic field.

Electromagnetic Field

A rapidly moving electric field and its associated moving magnetic field.

Electromagnetic Induction

The production of a voltage in a coil due to a change in the number of magnetic lines of force (flux linkages) passing through the coil.

Electromagnetic Interference (EMI)

Flowing currents generate magnetic fields. Depending on the strength and proximity, these magnetic fields can induce unwanted current in nearby conductive media, negatively affecting signal transfer.

Electromotive Force (E.M.F)

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

Electronic Wire and Cable

A length of conductive or semiconductive material used in an electronic application.

Electrostatic

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

Electrostatic Shield

A copper or laminated aluminum/mylar tape wrap around a signal or instrumentation circuit (pair, triad, etc.) to protect from the electric field radiated by a voltage source. The grounded shield intercepts static interference and carries it off to ground.

Electro-Tinned

Electrolytic process of tinning wire using pure tin.

Elongation

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

Elongation at Break

The tensile strain in a test piece stretched to breaking point, the conditions being such that the stress is substantially uniform over the cross - section.

Embossing

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

Emergency Overloads

Loads which occur when larger than normal currents are carried through a cable or wire over a short period of time.

EMI

Abbreviation for electromagnetic interference.

EMRC

Energy Mines and Resources Canada

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.

End Finish

Quality of the surface at an optic-fiber's end, commonly described as mirror, mist, hackle, chipped, cracked, or specified by final grit size used in polishing.

Ends

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

Energize

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

Entrance Facility, Telecommunications

An entrance to a building for both public and private network service cables (including antennae) including the entrance point at the building wall and continuing to the entrance room or space.

Entrance Point, Telecommunications

The point of emergence of telecommunications conductors through an exterior wall, a concrete floor slab, or from a rigid metal conduit or intermediate metal conduit.

Entrance Room or Space, Telecommunications

A space in which the joining of inter- or intra-building telecommunications backbone facilities takes place. An entrance room may also serve as an equipment room.

EPDM

Ethylene-propylene-dene monomer rubber. A material with good electrical insulating properties.

EPR

Ethylene-propylene copolymer rubber. A material with good electrical insulating properties.

Equal Load Sharing

An even distribution of current between the parallel cables in a power circuit.

Equilay

More than one layer of helically laid wires with the direction of lay reversed for successive layers, but with the length of lay the same for each layer.

Equipment Room, Telecommunications

A centralized space for telecommunications equipment that serves the occupants of the building. An equipment room is considered distinct from a telecommunications closet because of the nature of complexity or the equipment.

ESTA

Australian approval agency, Electricity Trust of South Australia.

Etched Wire

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

Ethernet

A local area network (LAN) which uses the CSMA/CD (Carrier Sense Multiple Access with Collision Detection) access method on a bus topography.

ETPC

Abbreviation for electrolytic tough pitch copper. It has a minimum conductivity of 99.9%.

Exit Angle

The angle between the output radiation vectors and the axis of the fiber or fiber bundle.

External Interference

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

External Wiring

Electronic wiring which interconnects subsystems within the system.

Extruded Cable

Cable with conductors which a re uniformly insulated and formed by applying a homogeneous insulation material in a continuous extrusion process.

Extrusion

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

F.P.A.

General Cable's trademark for polyethylene fused to aluminum for use as cable shielding.

FAA

Federal Aviation Administration.

False Ceiling

A ceiling that creates an area or space between the ceiling material and the structure above the material. Synonym: Drop Ceiling, Suspended Ceiling.

Farad

The standard unit of capacitance. A one farad capacitor is one in which a one coulomb charge produces a one volt potential difference between the plates.

Fatigue Resistance

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

FDDI (Fiber Distributed Data Interface)

A standard for a 100 Mbs fiber optic area network.

Feedback

Energy that is extracted from a high-level point in a circuit and applied to a lower level. Positive feedback reduces the stability of a device and is used to increase the sensitivity or produce oscillation in a system. Negative feedback, also called inv

Feeder Cable

In telecommunication or CATV systems, the transmission cable from the head end (signal pickup) to the trunk amplifier. Also called a Trunk Cable.

Feedthrough

(1) A conductor that connects patterns on opposite sides of a PCB. Also called Interfacial Connection; (2) A connector or terminal block, usually having double-ended terminals which permit simple distribution and bussing of electrical circuits.

Feed-Through Insulators

Insulators that carry a metal conductor through the chassis while preventing the 'hot' lead from shorting to the ground chassis.

FEP

Fluorinated ethylene propylene, a melt extrudable fluorocarbon resin. Teflon is a DuPont registered trademark.

Ferrous

Composed of and/or containing iron. A ferrous metal exhibits magnetic characteristics (i.e. steel armor).

Ferrule

A short tube used to make solderless connections to shielded or coaxial cable.

Fext

Far end crosstalk.

FI

Approval agency of Finland; Electrical Inspectorate.

Fiber

A single, separate optical transmission element characterized by core and cladding.

Fiber Channel

A high speed point-to-point, ANSI Optical Communications Standard that supports data transfer rates up to 1,062.5 Mbs (1 Gps).

Fiber Cleaving

Controlled fracture of an optical fiber along a crystalline plane which results in a smooth surface.

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.

Fiber Tubing

A loose, crush-resistant cylinder applied over individual fibers to provide mechanical protection.

Field

An area of influence around a magnet or electric charge.

Field Coil

A suitable insulated winding to be mounted on a field pole to magnetize.

Figure 8 Cable

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

Filament

Fiber characterized by extreme length.

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.

Filler

(1) A material used in the cable to fill large interstices between electrical components; (2) A substance, often inert, added to a compound to improve properties and/or decrease cost.

Film

A thin plastic sheet.

Fine Stranded Wire

Stranded wire with component strands of 36 AWG or smaller.

Firestop

A material, device, or assembly of parts installed in a cable system in a fire-rated wall or floor to prevent passage of flame, smoke, or gasses through the rated barrier.

Fixture Wire

Fixture wires according to the National Electrical Code are designed for installation in lighting fixtures and in similar equipment where enclosed or protected and not subject to bending or twisting in use. They also are used for connecting lighting fixtu

Flame Resistance

The ability of a material not to propagate flame once the heat source is removed.

Flame Retardance

Ability of a material to p revent the spread of combustion by a low rate of travel so the flame will not be conveyed.

Flammability

The measure of the material's 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 or flame and to self-extinguish when removed from this source.

Flashover

A disruptive discharge around or over the surface of a solid or liquid insulator.

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.

Flat Under Carpet Cable

A cable containing one or more cores, each formed of a group of wires, the diameters of the wires being sufficiently small to afford flexibility.

Flex Life

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

Flexibility

The ease with which a cable may be bent without sustaining damage.

Flexible

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.

Flexible Cable

A cable containing one or more cores, each formed of a group of wires, the diameters of the wires being sufficiently small to afford flexibility.

Floating

Referring to a circuit which has no connection to ground.

Flux

(1) The lines of force which make up an electrostatic field; (2) The rate of flow of energy across or through a surface; (3) A substance used to promote or facilitate fusion.

FNC

Federal Networking Council (formerly FRICC).

Foam Skin Cable

A cable utilizing a foamed polyolefin inner layer covered by a solid polyolefin skin as the conductor insulation.

Foamed Plastics

Plastic insulations having a cellular structure.

Foamskin

Polyethylene foam insulation with polyethylene outerskin.

Foil

A thin, continuous sheet of metal.

FOTP

Abbreviation for fiber optic test procedures, which are defined in TIA/EIA Publication Series 455.

FR-1

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.

Free Connector

A connector for attachment to the free end of a wire or cable.

Frequency

The number of cycles, now expressed as hertz, by an alternating current in one second. The hertz is equivalent to the older unit cycles per second.

Frequency Response

The characteristic of a device denoting the range of frequencies over which it may be used effectively.

FT1

One of several CSA flame test designations for wires and cables which pass the C22.2 No. 0.3 test requirements. (Other designations include FT2, FT4, etc.)

Funnel Entry

Flared or widened entrance to a terminal or connector wire barrel.

Fuse Wire

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

Fused Coating

A metallic coating which has been melted and solidified, forming a metallurgical bond to the base material.

Fused Conductors

Individual strands of heavy tinned copper wire stranded together and then bonded together by induction heating.

Fused Spiral Tape

A PTFE insulated hookup wire. The spiral wrapped conductor is passed through a sintering oven whereoverlaps are fused together.

Fusion Splice

A splice accomplished by the application of localized heat sufficient to fuse or melt the ends of two lengths of optical fiber, forming a continuous single fiber.
   
G

G round Potential

Zero potential with respect to the ground or earth.

Gain

The increase of voltage, cur rent, or power over a standard or previous reading. Usually expressed in decibels.

Galvanometer

An instrument for detecting or measuring small electrical current.

Gang Strip

Simultaneous stripping of 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.

Gauge

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

Giga

A numerical prefix denoting one billion (109).

Gigabit

One billion bits of information.

Gigahertz (GHz)

A unit of frequency equal to one billion hertz.

Gimmick

A short length of wire soldered onto a circuit component and used as a small adjustable capacitor.

GND

Abbreviation for ground.

Graded-Index

A type of optical fiber in which the refractive index of the core is in the form of a parabolic curve, decreasing toward the cladding. This type of fiber provides high bandwidth capabilities.

Graded-Index Fiber

An optical fiber core that has a non-uniform index of refraction. The core is composed on concentric rings of glass, which have refractive indices that decrease from the center axis. The refractive index is changed in a systematic way from the center to t

Ground

(1) An electrical term meaning to connect to the earth or other large conducting body to serve as an earth thus making a complete electrical circuit; ( 2) A wire intended to be used for grounding (also called grounding conductor).

Ground Conductor

A conductor in a transmission cable or line that is grounded.

Ground Insulation

The insulation used between a winding and the magnetic core or other structural parts, usually at ground potential.

Ground Loop

The generation of undesirable current flow within a ground conductor, owing to the circulation currents which originate from a second source of voltage.

Ground Plane

Expanded copper mesh which is laminated into some flat cable constructions as a shield.

Ground Potential

Zero potential with respect to the ground or earth.

Ground Power Cable

A cable assembly fitted with appropriate terminations to supply power to an aircraft from ground power unit.

GTO

Gast tube sign and oil-burner ignition cable. 5,000V-15,000V.
   
H

Halar

A trade name of Allied Chemical for their copolymer of ethylene and chlorotrifluor-ethylene. Abbreviation ECTFE.

Halogen

A term used to identify any of the four elements chlorine, fluorine, bromine and iodine, grouped together because their chemical properties are similar.

Hard Drawn Copper Wire

Copper wire that has been drawn to size and not annealed.

Harness

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

Hash Mark Stripe

A non-continuous helical stripe applied to a conductor for identification.

Heat Distortion

Distortion of flow of a material or configuration due to the 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

In cabling, a method of sealing a tape wrap jacket by means of 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.

Heater Cord

Flexible stranded copper conductor, cotton wrapped with rubber insulation and asbestos roving.

Helical Stripe

A continuous, colored, spiral stripe applied over the outer perimeter of an insulated conductor for circuit identification purposes.

Helix

Spiral winding.

Henry

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 gas-tight enclosure that has been completely sealed by fusion or comparable means.

Hertz

Unit of measure of frequency of alternating current. One hertz is equal to one cycle per second.

Hertz (Hz)

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

Heterogeneous Insulation

A cable insulating system composed of two or more layers of different insulating materials.

High Temperature Wire and Cable

Electrical wire and cables having thermal operating characteristics of 150°C and higher.

High Voltage (HV)

Cables rated over 35Kv. The National Electrical Code defines any cable over 600 volts as High Voltage for the purposes of Article 710. However, Article 326 delineates the generally accepted parameters of Medium Voltage and High Voltage.

Hi-Pot (High Potential)

A test designated to determine the highest voltage that can be applied to a conductor without breaking down the insulation (see Dielectric Test).

Holding Strength

Ability of a connector to remain assembled to a cable when under tension.

Homogeneous Insulation

A complete cable insulation structure whose components cannot be identified as layers of different materials.

Hook-up Wire

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

Horizontal Cabling

The wiring/cabling between the telecommunications outlet/connector and the horizontal cross-connect.

Horizontal Cross-Connect

A cross-connect of horizontal cabling to other cabling, i.e. horizontal, backbone, or equipment.

Horizontal Stripe

A colored stripe running horizontally with the axis of a conductor, sometimes called a longitudinal stripe, used as a means of circuit identification.

Hot Dip

A term denoting the covering of a surface by means of dipping the surface to be coated into a molten bath of the coating material.

Hot Stamping

Method of alpha numerical coding. Identification markings are made by pressing heated type and marking foil into softened insulation surfaces. See Surface Printing.

Hot Tin Dip

Rubber and asbestos-insulated heater cord . No braid on individual conductors but with braid overall. Also made with neoprene insulation and no asbestos or PVC/NBC.

HPN

Two-conductor, neoprene-insulated heater cord. Parallel construction. For use in damp locations.

HS

600V rated Rubber insulated Heater Cord.

HSJ

300V rated Rubber insulated Heater Cord.

Hybrid Cable

An assembly of two or more cables (of the same or different types or categories) covered by one overall sheath.

Hygroscopic

A material capable of absorbing and retaining moisture from the air.

Hypalon®

Dupont's trade name for their chlorosulfonated polyethylene, an ozone resistant synthetic rubber.

Hz

Abbreviation for Hertz.
   
I

ICEA

Abbreviation for Insulated Cable Engineers Association. (Formerly IPCEA).

IEC

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

IEEE

Abbreviation for Institute of Electrical and Electronics Engineers.

Ignition Cable

Cable designed for Automotive Ignition Systems.

Impact Strength

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

Impact Tool

Device used to punch new conductor onto ID's. This tool is typically equipped with a cutting blade for either 66 or 110 blocks.

Impedance

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, measured in ohms.

Impedance Match

A condition in which the impedance of a particular circuit cable or component is the same as the impedance of the circuit, cable or device to which it is connected.

Impedance Matching

Connecting cables and devices together which have the sameimpedance value in ohms.

Impedance Matching Transformer

A transformer designed to match the impedance of one circuit to that of another (BALUN).

Impregnate

To fill the voids and interstices of cable or the fabric of a cable with a compound.

Impulse (or Pulse)

A surge of unidirection a polarity.

Impulse Strength

The voltage breakdown of insulation under voltage surges on the order of microseconds in duration.

Impulse Test

An insulation test in which the voltage applied is an impulse voltage of specified wave shape.

IMSA

International Municipal Signal Association.

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.

Index of Refraction

The ratio of light velocity in a vacuum to its velocity in a given transmission medium.

Induced Current

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

Inductance

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

Induction

The phenomenon of a voltage, magnetic field, or electrostatic charge being produced in an object by lines of force from the source of such fields.

Inductive Coupling

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

Infrared (IR)

The range of electromagnetic wavelengths between the visible part of the spectrum (750 nm) and microwaves (30 µm).

Infrastructure, Telecommunications

A collection of those telecommunications components, excluding equipment, that together provide the basic support for the distribution of all information within a building or campus.

Insertion Loss

As measure of the attenuation of a device by determining the output of a system before and after the device is inserted into the system.

Insertion Tool

A small, hand-held tool used to insert contacts into a connector.

Inside Plant (ISP)

All cable and equipment inside a central office or subscriber's premises.

Inside Wire

Wire designed to carry a telephone circuit(s) through the customer's premises.

Insulated Wire

A conductor of electricity covered with a non-conducting material.

Insulating Joint

A device which mechanically couples and electrically insulates the sheath and armor of contiguous lengths of cable.

Insulation

A material having good dielectric properties permitting close assembly of conductors in cable and equipment.

Insulation Adhesion

The degree of tightness of the insulation over the base conductor, measured in terms of force required to remove a specified length of insulation from the wire.

Insulation Crimp

The area of a terminal, splice, or contact that has been formed around the insulation of the wire.

Insulation Grip

Extended cylinders at the rear of crimp-type contacts designed to accept the bared wire and a small length of its insulation.

Insulation Level

A designation used to identify the insulation thickness required to protect a high voltage cable under ground fault conditions. Expressed as a percentage (e.g. 100% level, 133% level).

Insulation Piercing

A method of crimping whereby lances cut the insulation of the wires and enter into the strands to make electrical contact.

Insulation Resistance

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

Insulation Shield (HV Cable)

A two part shield consisting of a non-metallic component and a metallic component. The first component is an extrusion of black semi-conducting thermoset material over the insulation which provides uniform radial stress distribution across the insulation.

Insulation Stress

High voltage stress which causes molecular separation in the insulation at sharp projections in the conductor. Controlled by conductor and insulation shielding, called a stress relief shield. Measured in volts per mil.

Insulation System

All of the insulation materials used to insulate a particular electrical or electronic product.

Insulation Thickness

The wall thickness of the applied insulation.

Integral Belt

A layer of insulation or semi-conductive material applied by extrusion over two or more insulated, twisted or parallel conductors to form a round smooth diameter.

Intensity

Irradiance.

Interaxial Spacing

Center to center conductor spacing.

Interbuilding

Between buildings.

Interconnect

A connection scheme that provides for the direct connection of individual cables to another cable or to an equipment cable without a patch cord.

Interconnect Companies

Companies which sell, install and maintain telephone systems for end users.

Interconnecting Cable

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

Interconnecting Wire

The physical wiring between components (outside a module) between modules, between units or between larger portions of a system or systems.

Interconnection

Mechanically joining devices together to complete an electrical circuit.

Interface

The two surfaces on the contact side of both halves of a multiple-contact connector which face each other when the connector is assembled.

Interference

Any to electrical signal induced into a conductor by electrical or electro-magnetic means.

Intermediate Cross-Connect

A cross-connect between 1st level and 2nd level backbone cabling.

Internal Wiring

Electronic wiring which interconnects components, usually within a sealed subsystem.

Interstices

Voids or valleys between individual strands in a conductor or between insulated conductors in a multiconductor cable.

Intrabuilding

Within a building.

Ionization

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.

Ionization Voltage (Corona Level)

The minimum value of falling rms voltage which sustains electrical discharge within the vacuous or gas filled spaces in the cable construction or insulation.

Irradiation

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

ISA

Instrument Society of America.

ISDN (Integrated Service Digital Network)

A digital data communications network providing full integration of data, voice and video.

ISO

International Standards Organization
   
J

Jack

A plug-in type terminal widely used in electronic apparatus for temporary connections.

Jacket

A material covering over a wire insulation or an assembly of components. An overall jacket on a complex cable grouping is also often referred to as a sheath. In fiber optics, a covering over a fiber, bundle of fibers, or cable which protects against th

JAN Specification

Joint Army-Navy specification (replaced by current Military Specifications).

Joule

A joule is a measurement of energy y. The joule rating on a surge protector indicates the amount of energy that a device is capable of absorbing. In general, the higher the joule rating, the better the unit is able to pro t e c t your equipment and the lo

Jumper

An assembly of twisted pairs without connectors used to join telecommunications circuits/links at the cross-connect. In fiber optic cable the cable that has connectors terminated on both ends.

Jumper Cable

A short flat cable interconnecting two wiring boards or devices.

Jumper Wire

PVC insulated connectors twisted together and used for cross-connecting on distributing frames.

Junction

A point in a circuit where two or more wires are connected.

Jute

A natural fiber of plant base formed into rope-like strands. Used in cables for filling the interstices to give a round cross-section.
   
K

kcmil

One thousand circular mils (MCM).

KEMA KEUR

Approval agency of the Netherlands

Kevlar

DuPont's trade name for Aramid material (see Aramid Yarn).

Keying

The mechanical feature of a connector system that guarantees correct orientation of a connection, or prevents the connection to a jack, or to an optical fiber adapter of the same type intended for another purpose.

Kilo

A numerical prefix denoting 1000.

Kilocycle

A term denoting one thousand cycles. (See Kilohertz)

Kilohertz

One thousand hertz, or one thousand cycles per second.

Kilometer

Unit of measure for length equal to 1000 meters and about 3,281 feet.

Kilovolt

A term denoting one thousand volts.

Kilowatt

A term denoting one thousand watts.

KPSI

Abbreviation used to denote a measurement unit of thousands of pounds per square inch. Commonly used in the fiber proof test tensile strength measurement.

kV

Kilovolt (1000 volts).

kW

Kilowatt

Kynar

Pennwalt trade name for polyvinylidene fluoride. Typically used as insulation for wirewrap wire.
   
L

Lacing and Harnessing

A method of grouping wires by securing them in bundles of designated patterns.

Lacquer

The term used in cable manufacture to designate the liquid resin or compound applied to a fibrous braid to prevent fraying, wicking, moisture absorption, etc., in the braid.

Laminated Flat Cable

Flat cable consisting of insulated conductors lying parallel, adjacent conductors joined by a web. Application in electronics, telecommunications, computers, etc.

Laminated Tape

A tape consisting of two or more layers of different materials bonded together (i.e. aluminum/Mylar®) .

Lamp Cord

Flexible stranded paralleled 2-conductor cord, rubber or plastic insulated. Used for speaker cord, fans, lamps, etc., where not subject to hard usage.

LAN (Local Area Network)

A network spanning a limited geographical area, providing data communications between computers and peripherals and switching equipment.

Laser

A device which produces a narrow band of light and is used as a transmitting device for light signals traveling along optical fibers. Laser is an acronym for Light Amplification by Stimulated Emission of Radiation.

Laser Diode

A semiconductor diode that, when pulsed, a laser diode emits coherent light.

Launch Angle

Angle between the propagation direction of the incident light and the optical axis of an optical waveguide.

Lay

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

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.

Layer

Consecutive turns of a coil lying in a single plane.

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

A wire, with or without terminals, that connects two points in a circuit.

Lead Cured

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

Lead Dress

The placement or routing of wire and component leads in an electrical circuit.

Lead-in

The conductor or conductors that connect the antenna proper to electronic equipment.

Leakage Current

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

LED

Acronym for Light Emitting Diode. It is a semiconductor device that emits incoherent light from a p-n junction (when biased with an electrical current).

Life Cycle

A test performed on a material or configuration to determine the length of time before failure in a controlled, usually accelerated environment.

Light

In the laser and optical communications fields, the portion of the electromagnetic spectrum that can be handled by the basic optical techniques used for the visible spectrum extending from the near ultraviolet region of approximately 0.3 micron, through t

Light Commercial Building

A building or portion thereof that is intended for use with one to four (1-4) non-residential exchange access lines per tenant.

Light Diffusion

Scattering of light by reflection or transmission. Diffuse reflection results when light strikes an irregular surface such as a frosted window or coated light bulb.

Light Emitting Diode

A semiconductor device that emits incoherent light from a p-n junction (when biased with an electrical current). Commonly called LED.

Light Intensity Ratio

Ratio of input light intensity to the output light intensity.

Light Source

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

Lightguide

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.

Lightwaves

Electromagnetic waves in the region of optical frequencies. The term "light" was originally restricted to radiation visible to the human eye, with wavelengths between 400 and 700 nm. However, it has become customary to refer to radiation in the speed regi

Limiting Oxygen Index

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

Limits of Error

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

Limpness

The ability of a cable to lay flat or conform to a surface.

Line Balance

The degree to which the conductors of a cable are alike in their electrical characteristics with respect to each other, to other conductors, and to ground.

Line Cord

A cord terminating in a plug at one end used to connect equipment or appliances to a power outlet.

Line Drop

A voltage loss occurring between any two points in a transmission line due to there sonance reactance or leakage of the line.

Line Loss

The total of the various energy losses occurring in a transmission line.

Line Voltage

The value of the potential existing on a supply or power line. Rated voltage of cables.

Link

An assembly of telecommunications facilities between two points, not including terminal equipment.

Listed

Equipment included in a list published by an organization, acceptable to the authority having jurisdiction, that maintains periodic inspection of production of listed equipment, and whose listing states either that the equipment or material meets appropri

LOCA

Abbreviation for loss of coolant accident, a system malfunction associated with nuclear generating stations.

Local Area Network (LAN)

A geographically limited communications network intended for the local transport of data, video, and voice.

Longitudinal Shield

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

Longitudinal Wrap

A tape applied longitudinally with the axis of the core being covered, as opposed to a helical, or spiral, tape wrapped core.

Loop Resistance

The total resistance of two conductors measured round trip from one end. Commonly used term in the thermocouple industry.

Looping-in

Wiring method which avoids tee joints by carrying the conductor or cable to and from the point to be supplied.

Loose-Tube

Type of cable design in which coated fibers are encased in buffer tubes offering excellent fiber protection and segregation. Mainly used in outdoor cable types.

Loss

Energy dissipated without accomplishing useful work.

Loss Factor

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

Lossy Line

A cable having large attenuation per unit of length.

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 or self-generated noise induced by either physical abuse or adjacent circuitry.

Low Tension

Low voltage, as applied to ignition cable.

Low Voltage

Defined by the National Electrical Code as 600 Volts and less. AEIC, ICEA, and UL generally define cables rated up to 2KV as Low Voltage.

Lug

A termination, usually crimped or soldered to the conductor, with provision for screwing on to the terminal.
   
M

m

Abbreviation for meter.

mA. Milliampere

One-thousandth of an ampere (10-3).

Macrobending

Macroscopic axial deviations of a fiber from a straight line.

Magnet Wire

Insulated wire intended for use in windings on motor, transformer, and other coils for electromagnetic devices.

Magnetic Field

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

Magnetic Flux

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

Magnetic Noise

Caused by current frequency. An AC powerline creates a magnetic field around that cable. This magnetic field causes the magnetic noise in neighboring control or instrumentation circuits.

Main Cross-Connect

A cross-connect for first level backbone cables, entrance cables and equipment cables.

Marker Tape

A tape laid parallel to the conductors under the sheath in a cable, imprinted with the manufacturer 's name and the specification to which the cable is made. Other information such as date of manufacture may also be included.

Marker Thread

A colored thread laid parallel and adjacent to the strands of an insulated conductor which identifies the cable manufacturer. It may also denote a temperature rating or the specification to which the cable is made.

Master Antenna Television (MATV)

A combination of components providing multiple television receiver operations from one antenna or group of antennas normally on a single building.

Material Scattering Loss

Loss due to fluctuations in the refractive index and to inhomogeneities in material composition and temperature.

MATV

Acronym for Master Antenna Television System-a combination of components providing multiple television receiver operations from one antenna or group of antennas normally on a single building.

MCF

Million conductor feet.

MCM

One thousand circular mils (kcmil).

MDPE

Acronym for Medium Density Polyethylene. MDPE is a form of polyethylene commonly used as a jacketing material for outdoor fiber optic cables. (See PE.)

Media, Telecommunications

Wire, cable, or conductors used for telecommunications.

Medium Voltage

2001 Volts to 35KV.

Meg or Mega

A numerical prefix denoting 1,000,000 (106).

MegaHertz

One million Hertz.

Megarad

A unit for measuring radiation dosage.

Megohm

One million ohms.

Member

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

Messenger

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

Mft

A popular abbreviation for 1000 ft.

Mho

The unit of conductivity. The reciprocal of an Ohm.

MHz

Megahertz (one million cycles per second). Formerly mc

Micro

A numerical prefix denoting one millionth.

Micro Farad

One millionth of a farad. This is the common unit for designating capacitance in electronics and communications.

Microbending

Curvatures of the fiber which involve axial displacements a few micrometers and spatial wavelengths of a few millimeters. Microbends cause loss of light and consequently increase the attenuation of the fiber.

Curvatures of the fiber which involve axial displacements a few micrometers and spatial wavelengths of a few millimeters. Microbends cause loss of light and consequently increase the attenuation of the fiber.

Loss due to small geometrical irregularities along the core-clad interface of the fiber.

Microfarad

One-millionth of a farad, commonly abbreviated mF.

Micrometer (µm)

One millionth of a meter or a micron. Conventional unit of measurement for optical fibers.

Micromicrofarad

One-millionth of a microfarad (uuf, uufd, mmf, mmfd mm F are common abbreviations).

Micron

(m) Millionth of a meter = 10-6 meter.

Microphonics

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

Microwave

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

Mil

A unit used in measuring diameter of a wire or thickness of insulation over a conductor. One one-thousandth of an inch (0.001").

Milli

A prefix denoting one-thousandth (10-3).

Mineral Insulated

Cable and thermocouple wire consisting of one or more conductors surrounded by magnesium oxide insulation and enclosed in a liquid- and gas-tight metallic sheathing.

Miniature Wire

Insulated conductors of approximately 20-34 AWG.

Mining Cable

A flame retardant cable especially constructed to withstand long time immersion or exposure to moisture for underground use in the environment of a mine or tunnel.

Mismatch

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

Modal Dispersion

Pulse spreading due to multiple light rays traveling different distances and speeds through an optical fiber.

Mode

One of the components of a general configuration of a propagating wave front.

Mode Field Diameter (MFD)

The diameter of optical energy in a singlemode fiber. Because the MFD is greater than the core diameter, MFD replaces core diameter as a practical parameter.

Modem

Device which places and receives data signals over a common carrier's communication facility.

Modular Jack

This term is outmoded, see Outlet/Connector, Telecommunications.

Modular Plug

A telecommunications connector for wire or cords per the Part 68 Rules. A modular plug can have 6 or 8 contact positions but not all the positions need be equipped with contacts.

Modulation

A process whereby certain characteristics of a wave, often called the carrier, are varied or selected in accordance with a modulating function.

Modulus of Elasticity

The ratio 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.

Molded Plug

A connector molded on either end of a cord or cable.

Monochromatic

Consisting of a single wavelength. In practice, radiation is never perfectly monochromatic but, at best, displays a narrow band of wavelengths.

Monomer

The basic chemical unit used in building a polymer.

Motor Lead Wire

Wire which connects to the usually fragile and easily damaged magnet wire found in coils, transformers, and stator or field windings. General requirements are abrasion resistance, toughness, flexibility, dielectric strength, thermal resistance and low pe

MPF

Million paired feet.

MTW

Thermoplastic insulated machine tool wire.

Multi-Conductor

More than one conductor within a single cable complex.

Multi-Conductor Cable

A cable consisting of two or more conductors, either cabled or laid in a flat parallel construction, with or without a common overall covering.

Multimedia Cable

A single communication cable used for the transmission of audio, data and video signals.

Multimode Fiber

An optical waveguide in which light travels in several modes. Typical core and cladding sizes are 62.5 and 125 µm, respectively.

Multimode Optical Fiber

An optical fiber that will allow many bound modes to propagate. The fiber may be either a graded-index or step-index fiber. See also: Optical Fiber Cable.

Multiple Conductor Concentric Cable

An insulated central conductor with one or more tubular stranded conductors laid over it concentrically and insulated from one another.

Multiple-Conductor Cable

A combination of two or more conductors cabled together and insulated from one another and from sheath or armor where used.

Multiplex

Combining two or more signals into a single bit stream that can be individually recovered.

Multiplexing

Simultaneous transmission of two or more messages over the same cable pair.

Mutual Capacitance (Cm)

The capacitance between two conductors when all other conductors, including the shield, are short circuited to 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.

Mylar

DuPont's trademark for polyethylene terephthalate (polyester) film used in the form of a tape.
   
N

Nano

A numerical prefix denoting one-billionth (10-9).

Nanometer (nm)

One billionth of a meter (10 -9 meter).

Nanosecond

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

National Electrical Code® (NEC)

A U.S. consensus standard published by the National Fire Protection Association (NFPA) and incorporated in OSHA regulations. (The Canadian Counterpart is the CE Code.)

National Electrical Code® Article 725

The NEC Article which covers remote control signal and communication power limited circuits that are not an integral part of the device or appliance.

National Electrical Code® Article 760

The NEC Article which covers the fire and burglar alarms installation of wire and equipment operating at 600 Volts or less.

National Electrical Code® Article 800

The NEC Article which covers telephone, telegraph as well as outside wiring for fireand burglar alarms.

NBS

National Bureau of Standards

NEC Type CL2

A Class 2 power-limited type cable for general use applications within a building under NEC Article 725, this type design is "Listed" by UL. These cables meet a 70,000 BTU flame test.

NEC Type CL2P

A Class 2 power-limited cable which is suitable for use in plenums in accordance with NEC Article 725. The cable meets the requirements of UL 910 the Steiner Tunnel test which classifies fire and smoke characteristics. The cable is "Listed" by UL.

NEC Type CL2R

A Class 2 power-limited cable which is suitable for use in riser shafts in accordance with NEC Article 725. These cables meet the UL 1666 flame test and are "Listed" by UL.

NEC Type CL2X

A Class 2 power-limited cable which is suitable for restricted applications (Iess than 0.25" in diameter in residences, exposed lengths less than 10f t.) or else in raceways under NEC Article 725. These cables meet a VW-1 flame test and a re Listed by UL.

NEC Type CM

A general application communications cable, Listed by UL, for use within buildings under NEC Article 800. It meets the requirements of the 70,000 BTU flame test.

NEC Type FPL

A general application fire p rotection cable for use within buildings in accordance with NEC Article 760. These cables are Listed by UL and meet the 70,000 BTU flame test.

NEC Type MP

A general use, multipurpose cable which may be employed interchangeably in either a communications (Article 800), power-limited (Article 725) or fire protective (Article 760) application.

NEMA

Abbreviation for National Electrical Manufacturers Association. (The Canadian counterpart is EEMAC).

NEMKO

Approval agency of Norway.

Neoprene

A synthetic rubber with good resistance to oil, chemicals and flame. Also called polychloroprene.

Network

1) Series of points connected by communications channels; 2) Network of telephone lines normally used for dialed telephone calls; 3) Network of communications channels connected to the use of one customer. For purposes of data communications applications

NEXT

Near end cross talk

NFPA

National Fire Protection Association.

Noise

In a cable or circuit, any extraneous signal which tends to interfere with the signal normally present in or passing through the system.

Nomex®

DuPont's trademark for a temperature resistant, flame-retardant nylon.

Non Hygroscopic

A material incapable of taking up or absorbing moisture from the air.

Non-Contaminating

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.

Numerical Aperture (NA)

Measure of the range of angles of incident light transmitted through a fiber. Depends on the differences in index of refraction between the core and the cladding. (The number that expresses the light gathering ability of a fiber.)

NVP

Nominal Velocity of Propagation.

Nylon

An abrasion resistant thermoplastic with good chemical resistance used for wire and cable jacketings.
   
O

Off Center

Conductor displaced within the cross-section of its insulation.

Offgassing

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

OFHC

Abbreviation for oxygen-free, high conductivity copper. It has no residual deoxidant, 99.95% minimum copper content and an average annealed conductivity of 101%.

Ohm

A unit of electrical resistance, the resistance of a circuit in which a potential difference of one volt produces a current of one ampere.

Oil Aging

Cable aged in an accelerated manner by placement in an oil bath and heated to a p re-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.

Opaque

Not permitting the passage of light.

Open Cell

Foamed or cellular material with cells which are generally interconnected.

Optical Communication Cable

Fiber with a protective jacket.

Optical Conductors

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

Optical Fiber Cable

An assembly consisting of one or more optical fibers.

Optical Fiber Duplex Adapter

A mechanical media termination device designed to align and join two duplex connectors.

Optical Fiber Duplex Connector

A mechanical media termination device designed to transfer optical power between two pairs of optical fibers.

Optical Return Loss (ORL)

The ratio, expressed in decibels, of optical power reflected by a component or an assembly to the optical power incident on a component or assembly that is induced into a link or system.

Optical Time Domain Reflectometer (OTDR)

An instrument used to measure the transmission performance of optical fibers.

Optical Waveguide

Dielectric waveguide with a core consisting of optically transparent material of low attenuation (usually silica glass) and with cladding consisting of optically transparent material of lower refractive index than that of the core. It is used for the tra

Oscillatory Surge

A surge which includes both positive and negative polarity values.

OSHA

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

Outgassing

The dissipation of gas from a dielectric evidencing decomposition.

Outlet Box, Telecommunications

A metallic or nonmetallic box mounted within a wall, floor or ceiling and used to hold telecommunications outlet/connectors or transition devices.

Outlet/Connector, Telecommunications

A connecting device in the work area on which horizontal cable terminates.

Outside Plant (OSP)

All cables and wires extending outward from the network protectors on the main distribution frame to connect the terminal equipment to the Outside Plant.

OVE

Approval agency of West Germany; Oesterreichischer Verband fur Elektrotechnik.

Over Current

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

Overall Diameter

Finished diameter over wire or cable.

Overcoat

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

Overcoat Conductor

A stranded conductor made from individual strands of tin coated wire stranded together, and then given an overall tin coat.

Overlap

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

Overload Capacity

The maximum level of current, voltage, or power which a device can withstand before it is damaged.

Oxygen Index

Percentage of oxygen necessary to support combustion in a gas mixture. Flame retardant materials have a higher oxygen index.

Ozone

Reactive form of oxygen, typically found a round electrical discharges and present in the atmosphere in small quantities.

Ozone Test

Exposure of material to a high concentration of ozone to give an accelerated indication of oxidation in normal environments and in proximity to ozone producing apparatus.
   
P

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.

Pair

Two wires forming a single circuit, held together by twisting, binding or a common jacket. Also known as a balance transmission line.

Pairing

The union of two insulated single conductors through twisting.

PAP

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

Parallel

A construction in which two or more conductors are laid parallel and surrounded and separated by an insulating material.

Parallel Cable

Two or more cables used to share the current in heavily loaded power circuits which permits the use of smaller conductors.

Parallel Pair

A duplex construction of two insulated conductors laid parallel and then covered overall with a braid or jacket.

Parallel Stripe

A stripe applied longitudinally on a wire or cable parallel to the axis of the conductor.

PASP

A cable sheath consisting of an inner polyethylene (P) jacket, corrugated aluminum (A) shield, corrugated steel (S) and an outer polyethylene (P) jacket.

Patch Cable

A cable with plugs or terminals on each end of the conductors to temporarily connect circuits of equipment together.

Patch Cord

A length of cable with connectors on one or both ends used to join telecommunications links/circuits at the cross-connect.

Patch Cord Cable

Bulk cable used in the manufacture of patch cords.

Patch Panel

A cross-connect system of mateable connectors that facilitates administration.

Pathway

A facility for the placement of telecommunications cable. Synonym: Raceway.

Pay-Off

The process of feeding a cable or wire from a bobbin, reel, or other package.

PBT

Poly-Butylene Terephthalate. A type of plastic.

PCB

Printed Circuit Board.

PE

Abbreviation used for polyethylene. Polyethylene is a type of plastic, commonly used as a jacketing material for outside plant cables, that possesses good mechanical properties including good moisture resistance. However, it is very flammable and not sui

Peak Voltage

The maximum instantaneous voltage

Percent Conductivity

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

Percent Plating

Quantity of plating on a conductor expressed as a percentage by weight.

Percentage Conductivity

Conductivity of a material expressed as a percentage of that of copper. Also used to indicate ratio of conductance between the phase conductor and the neutral in power cables.

Periodicity

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.

Permittivity

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 (SIC).

Phase

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 the phase relationship between two alternating quantities.

Photodetector (Receiver)

Converts light energy to electrical energy.

PIC

An abbreviation for Plastic Insulated Conductor: conductors covered with an extruded coating of plastic.

Pick

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

PICO

A prefix denoting one-millionth of one-millionth (10-12).

Picofarad

One trillionth of a farad. A unit capacitance usually used to designate capacitance unbalance between pairs and capacitance unbalance of the two wires of a pair to ground. (abbreviation pf)

Pigtail

A fiber optic connector that is terminated to one end of an optical fiber cable. A short length of optical fiber, permanently fixed to a component, used to couple power between the component and a transmission fiber.

Pigtail Wire

Fine stranded, extra flexible, rope lay lead wire attached to a shield for terminating purposes.

Pitch

In flat cable, the nominal distance between the index edges of two adjacent conductors.

Pitch Diameter

Diameter of a circle passing though the center of the conductors in any layer of a multi-conductor cable.

Plain Conductor

A conductor consisting of only one metal.

Plain Weave

A weave used on woven cables. Threads between the wires act as binders and give the cable lateral stiffness and linear flexibility. Also called Standard and Square Weave.

Planetary Cabler

A cabler capable of laying down any number of shielded, overbraided, jacketed single conductors or 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 about one another so the wire will not kink as it is twisted.

Plastic

Also called thermoplastic, high polymeric substances, including both natural and synthetic products, but excluding the rubbers, that are capable of flowing under heat and pressure.

Plastic Deformation

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

Plasticizer

A chemical agent added in compounding plastics to make them softer and more flexible.

Plating

The application of one metal over another.

Plenum

The air handling space such as that found above drop-ceiling tiles or in raised floors. It is also the most stringent fire code rating for indoor cables.

Plenum Cable

A cable that meets the most stringent flammability and smoke-generating tests and is approved by a recognized agency such as UL for installation in plenums without the need for conduit.

PLSJ

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

PLT

Same as PLSJ except thermoplastic insulation.

Plug

The part of the two mating halves of a connector which is movable when not fastened to the other mating half.

Ply

The number of individual strands or filaments twisted together to form a single thread.

Point-to-Point Wiring

An interconnecting technique wherein the connections between components are made by wires routed between connecting points.

Polarization

The orientation of a flat cable or a rectangular connector.

Polishing

Act of smoothing ends of fibers to an optically smooth finish, generally using abrasive.

Polychloroprene

Chemical name for Neoprene. A rubber-like compound used for jacketing where wire and cable will be subject to rough usage, moisture, oil, greases, solvents and chemicals. May also be used as low insulating material.

Polyester

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

Polyethylene (PE)

A family of insulating materials derived from polymerization of ethylene gas. They are basically pure hydrocarbon resins with excellent dielectric properties.

Polyhalocarbon

A general name for polymers containing halogen atoms. The halogens are fluorine, chlorine, bromine and iodine.

Polymer

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

Polymerization

A chemical reaction in which low molecular weight molecules unite with each other to form molecules with higher molecular weights.

Polyolefin

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.

Polypropylene (PPE)

A thermoplastic similar to polyethylene but stiffer and having higher softening point (temperature); excellent electrical properties.

Polyurethane (PUR)

This thermoplastic material is used primarily as a cable jacket material. It has excellent oxidation, oil, and ozone resistance. Some formulations also have good flame resistance. It is a hard material with excellent abrasion resistance. It has outstandi

Polyvinylchloride (PVC)

A thermoplastic material composed of polymers of vinyl-chloride which may be rigid or elastomeric, depending on specific formulation.

Porosity

Multiple air voids in an insulation or jacket wall.

Portable Power Cable

Flexible, all rubber insulated for hard usage. Some cables have shielded conductors (metallic or non-metallic) and can have neoprene sheath overall.

POSJ

All-rubber, parallel light duty rip-cord for use on lamps and small appliances. 300V, 60°C.

POT

Thermoplastic, parallel, light duty rip-cord. 300V, 60°C to 105°C.

Potting

The sealing of a cable termination or other component with a liquid which thermo-sets into an elastomer or solid compound to exclude moisture .

Power

The rate at which energy is transferred.

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 the angle between the voltage applied and the current resulting.

Pre-Bond

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

Preform

A glass structure from which an optical fiber waveguide can be drawn.

Pressurization

The use of pressurized gas or dry air inside Air Core cables to prevent the entry of water at faulty splices or minor sheath cracks. It can also trigger an alarm when major faults occur and can assist in locating the damaged areas.

Pre-Wiring

The practice of concealing station wire or cable in the walls of buildings while they are being constructed. It is cheaper and more satisfactory for the owner.

Primary

The transformer winding which receives the energy from a supply circuit.

Primary Coating

The plastic coating applied directly to the cladding surface of the fiber during manufacture to preserve the integrity of the surface.

Primary Insulation

A non-conductive material, usually the first layer over a current carrying conductor, whose prime function is to act as an electrical barrier for the applied potential.

Primary Protection

The minimum protection required on all exposed facilities to comply with NEC requirements.

Primary Wiring

A printed circuit intended to provide point-to-point electrical connections.

Programming

Ability to select various circuit patterns by interconnecting appropriate contacts on one side of a connector plug or panel.

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.

Protocol

A set of rules for communicating.

Proximity Effect

Non-Uniform current distribution over the cross-section of a conductor caused by the variation of the current in a neighboring conductor.

PTFE

Abbreviation for Polytetrafluoroethylene.

Pull Box

A device to access a raceway used to facilitate placing of wire or cables.

Pull Cord/Pull Wire

Cord or wire placed within a raceway and used to pull wire and cable through the raceway.

Pull Strength

The maximum pulling force that can be safely applied to a cable without damage.

Pull Tension

The maximum pulling force that can be safely applied to a cable without damage.

Pulling Eye

A device which may be fastened to the conductor or conductors of a cable or formed by or fastened to the wire armor and to which a hook or rope may be directly attached in order to pull the cable into or from a duct.

Pulse

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

Pulse Cable

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

Put-Up

Refers to the packaging of wire and cable. The term itself refers to the quantity of product that is ready to be stored or shipped.

PVC

Abbreviation used for polyvinyl chloride. Polyvinyl chloride is a plastic material that is widely used as a jacketing material in indoor cables.

PVDF

Abbreviation denoting polyvinylidene fluoride, a fluoropolymer plastic material often used as a jacket in plenum cables, especially in larger fiber count cables.
   
Q

Quad

A series of four separately insulated conductors, generally twisted together in pairs. Also, a series-parallel combination of transistors with increased reliability because failure of one transistor will not disable the entire circuit.

Quadders

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

Raceway

Any channel designed for holding wires or cables, i.e. conduit, electrical metallic tubing, sleeves, slots, underfloor raceways, cellular floors, surface raceways, lighting fixture raceways, wireways, cable troughs, busways, auxiliary gutters, and ventila

Rack

The vertical or horizontal open support (usually made of aluminum or steel) that is attached to a ceiling or wall.

Radio Frequency

The frequencies in the electromagnetic spectrum that are used for radio communications.

Random Winding

A winding in rotating equipment wherein the wires do not lie in an even pattern .

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 .

RBOC (Regional Bell Operating Company)

A holding company formed by the divestiture of AT&T to provide both regulated and non-regulated telephone services.

REA

Rural Electrification Administration. A branch of the U.S. Department of Agriculture. Now RUS.

Reactance

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

Reactance Drop

With AC, that component of the voltage drop which is in quadrature with the current and equals the current in amperes multiplied by the reactance in ohms between the two points.

Receiver

A detector and electronic circuitry to change optical signals into electrical signals.

Red Plaque

A powdery, brown-red growth found on silvercoated copper conductors and shield braids.

Redraw

The drawing of wire which has already been drawn to an intermediate size, through a series of dies, to reach a desired wire size.

Reducing Joint

A joint between two lengths of cable where the conductors are not the same size.

Reel

A revolvable flanged device made of wood or metal, used for winding flexible metal wire or cable.

Reel Drum Diameter

Diameter of the drum (or hub) of the reel.

Reel Flange Diameter (Reel Height)

Diameter of the reel flanges

Reel Traverse

Width of space between reel flanges.

Reel Width

Overall width of reel.

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

The abrupt change in direction of a light beam at an interface between two dissimilar media so that the light beam returns into the media from which it originated.

Reflection Loss

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

Reflow Soldering

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

Refraction

The bending of a beam of light at an interface between two dissimilar media or in a medium whose refractive index is a continuous function of position (graded index medium).

Refractive Index

The ratio of the velocity of light in a vacuum to that in an optically dense medium.

Registration

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

Reinforced Sheath

The outermost covering of a cable that has a cable sheath construction in layers with a reinforcing material, usually a braided or double spiral fiber, molded in place between layers.

Reinforcement

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

Remanence

The magnetic induction that remains in a magnetic circuit after the removal of an applied magnetomotive force.

Repeater

A device which consists of a transmitter and a receiver or transmitter, used to regenerate a signal to increase the system transmission length. In an optical-fiber communication system, an optoelectronic device or module that receives an optical signal.

Resin

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.

Resistance

A measure of the difficulty in moving electrical current through a medium when voltage is applied. It is measured in ohms.

Resistive Conductor

A conductor with high electric resistance.

Retractile Cable

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

Retractile Cord

A cord having specially treated insulation or jacket so that it will retract.

Return Loss

Backward reflected energies from uneven parts of the cable structure causing impedance variations. Return Loss is necessary for bi-directional applications.

Return Wire

A ground wire or the negative wire in a direct-current circuit.

RF

Abbreviation for radio-frequency.

RFI

Radio Frequency Interference.

RG/U

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

RHH

Rubber-insulated, heat resistant building wire, 90°C, dry locations.

RHH-2

Ditto, 90°C, wet or dry.

RHW

Rubber-insulated building wire, heat and moisture resistant, 75°C 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, generally used for telecommunication.

Ridge Marker

One or more ridges running laterally along the outer surface of a plastic insulated wire for purposes of identification.

Rigid Bay

Cabling equipment that maintains component sequence, and can produce cables with distinct layers.

Rigid Coaxial Cable

Non-flexible coaxial cable, usually a metal tube armored coaxial cable.

Ring Banding

A circumferential color band applied to an insulated conductor at regular intervals for identification.

Ring Tongue

A solderless terminal that connects wire to a stud.

Ringing Out

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

Rip Cord

(1) Two or more insulated conductors in a parallel configuration which may be separated to leave the insulation of each conductor intact; (2) A small filament cord used to rip through the outer cable sheath.

Riser

Pathways for indoor cables that pass between floors. It is normally a vertical shaft or space. A riser cable rating indicates good flammability characteristics, but not necessarily low smoke as in a plenum type.

Riser Cable

The vertical section of a building cable extending from one floor to another.

Root Mean Square (RMS)

The effective value of an alternating current or voltage.

Rope Concentric

A group of standard conductors assembled in a concentric manner.

Rope Lay Conductor

A conductor composed of a central core surrounded by one or more layers of helically laid groups of wires used in portable cables.

Rope Strand

A conductor composed of a center group of twisted strands surrounded by one or more layers of similar groups of twisted strands.

Rope Unilay

A group of stranded conductors assembled in a unilay manner.

Round Conductor

A conductor whose cross-section is substantially circular.

Round Wire Shields

Shields constructed from bare, tinned or silver plated copper wire that include braided, spiral, and reverse spiral.

Routers

A device that determines how to forward a packet toward its destination, based on tables that indicate the costs, congestion status, and other factors associated with possible routes. Also called a Level 3 Relay or an Intermediate System.

Routing

The path followed by a cable or a conductor.

Rubber

A general term used to describe wire insulation and jackets made of thermosetting elastomers, such as natural or synthetic rubbers, EPR, neoprene, Hypalon, butyl rubber and others.

Rulan

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

Rupture

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

RUS

Abbreviation for Rural Utilities Service.
   
S

S

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.

SAE

Society of Automotive Engineers.

SANZ

Standards Association of New Zealand.

SBC

Soft bare copper.

SBR

A copolymer of styrene and butadiene. Also GR-S or Buna-S. Most commonly used type of synthetic rubber.

Scattering

Property of glass that causes light to deflect from the fiber and contributes to optical attenuation.

Screen

A shield placed over the entire core.

Screened Cables

A cable core design where an aluminum shield divides the cable core into two electrically separate compartments.

Secondary Insulation

A nonconductive material that protects the conductor against abrasion and provides a second electrical barrier.

Segmental Conductor

A stranded conductor consisting of three or more stranded conducting elements, each element having approximately the shape of the sector of circle, assembled to give a substantially circular cross-section.

Selenium Cure

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

Self Extinguishing

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

Self-Supporting Aerial Cable

A cable consisting of one or more insulated conductors 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 or steel sheath for added tensile strength, thus enabling it to be suspended between widely spaced supports.

Semi-Conducting Jacket

A jacket having a sufficiently low resistance so that its outer surface can be kept at substantially ground potential.

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.

Semi-Conductor

In wire industry terminology, a material possessing electrical conductivity that falls somewhere between that of conductors and insulators. Usually made by adding carbon particles to an insulator (e.g. conductor shield and insulation shield). Not the same

Semi-Rigid

A cable containing a flexible inner-core and a relatively inflexible sheathing material, such as a metallic tube, but which can be bent for coiling or spooling and placing in a duct or cable run.

Semi-Rigid PVC

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

Semi-Solid

An insulation cross-section having a partially open space between the conductor and the insulation perimeter.

SEMKO

Approval agency for Sweden.

Separator

A layer of insulating material which is placed between a conductor and its dielectric, between a cable jacket and the components it covers, or between various components of a multiple-conductor cable.

Series Circuit

A circuit in which the components are arranged end-to-end to form a single path for current.

Serve

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

Served Wire Armor (SWA)

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

Serving

A wrapping applied over the core of a cable or over a wire.

Sheath

The combination of a metallic shield and an extruded plastic jacket applied as the outermost covering on a cable. In the absence of a shield, the extruded jacket may be designated as a sheath.

Shield

A metallic layer placed around an insulated conductor or group of conductors to prevent electrostatic or electro magnetic interference between the enclosed wires and external fields. This shield can be braided or served wires, foil wrap, foil backed tape

Shield (Electrostatic)

In cables, a metallic layer placed around a conductor or group of conductors to prevent electrostatic interference between the enclosed wires and external fields. Also see Insulation Shield.

Shield Coverage

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

Shield Effectiveness

The ability of a shield to screen out undesirable signals.

Shielded Line

A transmission line whose elements confine propagated radio waves to an essentially finite space inside a tabular conducting surface called the sheath preventing the line from radiating radio waves.

Shielded-Type Cable

A cable in which the surface of the insulation is at ground potential.

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.

Shrink Tubing

Tubing which has been extruded, crosslinked, and mechanically expanded which when reheated will return to its original diameter.

Shunt Wire

A conductor joining two parts of an electric circuit to divert part of the current.

SIA

Steel Interlocked Armor.

SIC

Specific Inductive Capacity.

Side Wall Bearing Pressure (SWBP)

A term used in reference to the pressure on a cable which is being pulled around a curved surface under tension. If excessive, SWBP can damage cable components and reduce the life of the cable.

Signal

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 to operate signal circuit devices.

Silicone

A material made from silicone and oxygen. It can be in thermosetting elastomer or liquid form. The thermosetting elastomer form is noted for high heat resistance.

Silicone Treating

A silicone liquid treatment applied to insulated conductors to allow for easy jacket stripping.

Simplex

Transmission in only one direction. Generally a communications system or device capable of transmission in one direction only.

Sine Wave

A wave that can be expressed as the sine of a linear function of time, or space or both.

Single Mode Fiber

A fiber wave guide in which only one mode will propagate. The fiber has a very small core diameter of approximately 8mm. It permits signal transmission at extremely high bandwidths and is generally used with laser diodes.

Single-Ended

Unbalanced, such as grounding one side of a circuit or transmission line.

Single-Faced Tape

Fabric tape finished on one side with a rubber or synthetic compound.

Singlemode Fiber

Optical fiber with a small core diameter (typically 9 µm) in which only a singlemode, the fundamental mode, is capable of propagation. This type of fiber is particularly suitable for wideband transmission over large distances, since its bandwidth is limit

Sizing

Applying a material to a surface to fill pores.

SJ

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

SJEOW

Hard service thermoplastic or rubber-insulated conductors and oil resistant thermoplastic outer jacket. All elastomer construction. 300V, 90°C to 105°C. Weather resistant. Meets UL specifications.

SJEW

Hard service thermoplastic or rubber-insulated conductors and overall thermoplastic jacket. All elastomer construction. 300V, 90°C to 105°C. Weather resistant. Meets UL specifications.

SJO

Same as SJ, but Carolprene, oil-resistant compound outer jacket. Can also be made water-resistant. 300V, 60°C.

SJOO

Same as SJO but inner conductor insulation as well as the outer jacket is oil resistant.

SJT

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

SJTO

Same as SJT, but oil-resistant thermo-plastic outer jacket. 60°C.

SJTW

Hard usage thermoplastic or rubber-insulated conductors and overall thermoplastic jacket. 300V, 60°C to You are not allowed to view links. Register or Login resistant for outdoor use.

Skeleton Braid

Widely separated braid of fiber copper, or steel, used to hold core together, for reinforcing jacket or for shielding.

Skew Rays

A ray that does not intersect the fiber axis. Generally, a light ray that enters the fiber core at a very high angle.

Skim Tape

Filled tape coated on one or both sides with a thin film of uncured rubber or synthetic compound to produce a coating suitable for vulcanization.

Skin Effect

The tendency of alternating current to concentrate and to travel only on the surface of a conductor. Tendency increases with increase in frequency.

Sleeve

A braided, knifed, or woven tube used over wires or components as insulation tubing. Also called Sleeving.

Sleeving

An extruded tube.

SO

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

Solder

A metal or metallic alloy used when melted to join metallic surfaces. To unite or join by solder.

Solid Conductor

A conductor consisting of a single wire.

Source

A light emitter, either an LED or laser diode, in a fiber optic link; a device that when properly driven will produce information carrying optical signals.

Source Coupling Loss

Loss of light intensity as light from source passes into fiber.

SP-1

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

SP-2

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

SP-3

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

Space, Telecommunications

An area used for housing the installation and termination of telecommunications equipment and cable, i.e., telecommunications closets, work areas and manhole/handholes.

Spacing

Distance between the closest edges of two adjacent conductors.

Span

(1) In flat conductors, the distance between the reference edge of the first and the last conductor; (2) In round conductors, the distance between centers of the first and last conductors ; (3) In aerial cable, the distance between poles or support clamp

Spark Test

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

Specific Gravity

The ratio of the weight of any volume of substance to a weight of an equal volume of some substance taken as a standard, usually water for liquids and hydrogen for gases.

Specific Inductive Capacity (SIC)

Same as dielectric constant (See Dielectric Constant).

Spectral Bandwidth

The difference between wavelengths at which the radiant intensity of illumination is half its peak intensity.

Spectral Response

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

Spectrum

Frequencies that exist in a continuous range and have a common characteristic.

Speed of Light

186,000 miles per second.

Spiral Marking

A continuous spiral mark applied to a conductor for identification.

Spiral Shield

A metallic shield of fine stranded wires applied spirally rather than braided.

Spiral Stripe

A color coding stripe applied helically to the surface of an insulated wire or cable.

Spiral Wrap

The helical wrap of a tape or thread over a core.

Splice

A connection of two or more conductors or cables to provide good mechanical strength as well as good conductivity.

Splice Closure

A device used to protect a cable or wire splice.

Spool

A revolvable flanged device made of wood or metal, used for winding flexible metal wire or cable.

Spread Spectrum

A modulation technique for multiple access, or for increasing immunity to noise and interference.

SPT-1

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

SPT-2

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

SPT-3

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

Square Mil

The area of a square one mil by one mil.

SRD

Portable range or dryer cable. Three or four rubber-insulated conductors with rubber or neoprene jacket, flat or round construction. 300V, 60°C.

SRDT

Same as SRD. Except all-thermoplastic with a maximum temperature of 90°C.

ST

H a rd service cord, jacketed, same as Type S except all-plastic construction. 600V, 60°C to1 0 5 ° C .

ST® Connector

Type of connector used on fiber optic cable utilizing a spring loaded twist and lock coupling similar to the BNC connectors used with coaxial cabling.

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 750C for a specified time.

STALPETH

A cable sheath consisting of a corrugated steel (ST) shield applied over a corrugated aluminum (AL) shield and an outer polyethylene (PETH) jacket.

Standing Wave

The stationary pattern of waves produced by two waves of 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 (SWR)

In a transmission line, waveguide, or analogous system, a figure of merit used to express the efficiency of the system in transmitting power.

Star Topology

A topology in which each telecommunications outlet/connector is directly cabled to the distribution device.

Static Condition

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

Station Wire

PVC jacketed wire specially designed for use in ducts or stapled to surfaces for direct connection to subscriber's phone.

Stay Cord

A component of a cable used to anchor the cable ends at their points of termination and to keep any pull of the cable f rom being transferred to the electrical connections.

Step Index Fiber

A fiber having a uniform refractive index within the core and a sharp decrease in refractive index at the core/cladding interface.

STO

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

Strand

(1) A single uninsulated wire; (2) One of the wires of any stranded conductor.

Strand Conductor Shield

A layer of semiconducting material or tape applied directly over the stranded conductor of cables rated 2,000 volts and higher. This reduces the possibility of high stress points occurring between the conductor and insulation.

Strand Lay

A distance of advance of one strand of a spirally stranded conductor, in one turn, measured axially.

Stranded Conductor

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

Strap

Square- or rectangular-section bare conductor manufactured and used in coil form.

Strength Member

Part of a fiber optic cable composed of aramid yarn, steel strands, or fiberglass filaments that increase the tensile strength of the cable.

Strip

To remove insulation from a cable.

Strip Force

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

Structural Return Loss

Backward reflected energies from uneven parts of the cable structure causing impedance variations are termed structural return loss.

STW

Extra hard usage cord, jacketed. 600V, 60°C to 105°C. Weather resistant for outdoor use.

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 cur rent in an electric circuit or cable. Also called Transient.

Surge

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

Surlyn

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

Suspended Ceiling

A ceiling that creates an area or space between the ceiling material and the structure above the material. Synonym: Drop Ceiling, Suspended Ceiling.

SV

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

SVO

Same as SV, except caro l p rene jacket. 300V, 6 0 ° C .

SVT

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

Sweep Test

A method to determine the frequency response of a cable by generating an RF voltage whose frequencies 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.
   
T

T1

A common carrier circuit leased (private line facility) which is the standard method of interconnecting digital communications systems in North America. The line operates at rate of 1.544M bps. With DS-1 signaling, the facility provides twenty-four 64 Kbp

Take-Up

The process of accumulating wire or cable onto a reel, bobbin, or some other type of pack. Also, the device for pulling wire or cable through a piece of equipment or machine.

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

A relatively narrow woven or cut strip of fabric, paper, or film material.

Tape Cable

A form of multiple conductor consisting of parallel metal strips imbedded in insulating material.

Tape Wrap

A spirally applied tape over an insulated or uninsulated wire.

Taped Insulation

Insulation of helically wound tapes applied over a conductor or over an assembled group of insulated conductors.

Taping

Process of insulating continuous length, large diameter wires with tape of non-extrudable materials.

Tarnish

A term used to describe a discolored or stained conductor or shield wire caused by exposure to the atmosphere.

TB

Terminal Block.

T-Carrier (AT&T)

A hierarchy of digital systems designed to carry speech and other signals in digital form, designated T1, T2, and T4. T1 carrier has 24 PCM voice channels.

Tear Strength

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

Teflon

DuPont's Company trade name for fluorocarbon resins. FEP, PFA and TFE are typical materials.

Tefzel

DuPont's trade name for a fluoro carbon material typically used as a wire wrap insulation.

Telecommunications

The communication of information over some distance, including interbuilding and intrabuilding distances.

Telecommunications Grounding Busbar

A common point of connection for telecommunications system and bonding to ground, which is located in the telecommunications closet or equipment room.

Telecommunications Infrastructure

A collection of those telecommunications components excluding equipment, that together provide the basic support for the distribution of all information within a building or campus.

Telemetry Cable

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

Temperature Rating

The maximum temperature at which an insulating material may be used in continuous operation without loss of its basic properties (i.e. operating, overload, short circuit). The minimum temperature for safe handling.

Tensile Strength

The pull stress required to break a given specimen. Measured in pounds per square inch. Also referred to as Ultimate Tensile Strength.

Tension Member

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

Terminal

(1) A point at which information may enter or leave a communications network; (2) The input-output associated equipment; (3) A device by means of which wires may be connected to each other.

Terminals

Metal wire termination devices designed to handle one or more conductors, and to be attached to a board bus or block with mechanical fasteners or clipped on.

Terminating Cable

A multi-paired cable usually with tinned conductors and always with fire resistant insulation that is used primarily between the cable vault and the main distributing frame.

Test Lead

A flexible, insulated lead wire used for making tests, connecting instruments to a circuit temporarily or for making temporary electrical connections.

TEW

Canadian Standard Association type appliance wires. Solid or stranded single c o n d u c t o r, plastic-insulated. 600V, 105°C.

Textile Braid

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

TF

Fixture wire, thermoplastic-covered solid or 7 strands. 60°C.

TFE

Tetrafluoroethylene. A thermoplastic material with good electrical insulating properties and chemical and heat resistance.

TFF

Same as TF but flexible stranding. 60°C.

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 functions without undue degradation.

Thermal Shock

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

Thermocouple

A 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 complementing 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 Lead Wire

An insulated pair of wires used from the couple to a junction box.

Thermocouple Wire

A two conductor cable, each conductor employing a dissimilar metal, made up especially for temperature measurements.

Thermoplastic

A material that can be softened repeatedly by heating and hardened by cooling through a temperature range characteristic of the plastic and that in the softened state can be shaped by molding or extrusion.

Thermoset

A plastic material which is crosslinked by a heating process known as curing. Once cured, thermosets cannot be reshaped.

Thermosetting

Term describing insulation that will not resoften or distort from its formed shape by heating until a destructive temperature is reached.

THHN

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

Three Conductor Cable

Three insulated conductors assembled with other necessary cable components (shield, filler, etc.) to form a core, protected by an overall jacket.

Three-Phase Current

Current delivered through three wires, with each wire serving as a return for the other two.

Three-Phase Three-Wire System

An alternating current supply system comprising three conductors over which three-phase power is sent.

Three-Wire System

A DC or single-phase AC system comprising three conductors, one of which is maintained at a potential midway between the potential of the other two.

THW

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

THWN

75°C, 600 volt, nylon jacketed building wire for dry and wet locations.

THWN-2

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

Tight Buffer

Type of cable construction whereby each glass fiber is tightly buffered by a protective thermoplastic coating to a diameter of 900 µm. Increased buffering provides ease of handling and connectorization.

Time-Division Multiplex (TDM)

The process or device by which more than one signal can be sent over a single channel by using different time intervals for the different signals. This may be done by varying the pulse duration, pulse amplitude and pulse position.

Tin Overcoat (TOC)

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

Tinned Copper

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

Tinned Wire

Copper wire that has been coated with a layer of tin or solder to simplify soldering.

Tinsel

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

A low voltage, stranded wire where each strand is a very thin conductor ribbon spirally wrapped around a textile yarn. Insulation is generally a textile braid. Intended usage is for severe flexing.

Topcoat

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

Topology

The physical or logical arrangement of a telecommunications system.

Total Internal Reflection

The total reflection that occurs when light strikes an interface at angles of incidence greater than the critical angle.

Tracer

A means of identifying polarity.

Tracer Stripe

When more than one color coding stripe is required, the first, or widest, stripe is the base stripe, the other, usually narrower stripes, being termed tracer stripes.

Transducer

A device for converting mechanical energy to electrical energy.

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

Transition Point

A location in the horizontal cabling where flat undercarpet cable connects to round cable.

Transmission

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

Transmission Cable

Two or more transmission lines. See Transmission Line.

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.

Transmission Media

The various types of wire and optical fiber cable used for transmitting voice or data signals. Typically, wire cable includes twisted pair, coaxial, and twinaxial. Optical fiber cable includes single, dual, quad stranded, and ribbon.

Transmitter

The electronic package that injects an electrical signal or light signal over the transmission medium.

Transparent

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

Transposition

Interchanging the relative positions of wires to neutralize the effects of induction to or from other circuits or, to minimize interference pickup by the lead-in during reception.

Tray

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 multi-conductor or multi-pair control, signal or power cable specifically approved under the National Electrical Code and/or the Canadian Electrical Code for installation in trays.

Triad

Three insulated wires of a single circuit forming a unit. (Two or more units are cabled to form a multi-triad cable.)

Triaxial

A three-conductor cable with one conductor in the center, a second circular conductor shield concentric with the first, and third circular conductor shield insulated from and concentric with the first and second, usually with insulation, and over a braid

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 variations in capacitance between shielding and conductor as the cable as flexed.

Triple(Triad)

A cable consisting of three insulated single conductors twisted together.

Triple Cable

A cable composed of three insulated single conductors and one bare conductor all twisted together. It may or may not have a common covering of binding.

Triplex

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

Triplexed Cable

Three individual cables twisted together.

True Concentric

A stranded wire or twisted cable in which each successive layer has a reversed direction of lay from the preceding layer.

Trunk Cable

In telecommunication or CATV systems, the transmission cable from the head end (signal pickup) to the trunk amplifier. Also called a Trunk Cable.

Tubing

A tube of extruded non-supported plastic or metallic material.

TW

Thermoplastic vinyl-jacketed building wire, moisture-resistant 60°C.

Twin Cable

A pair of insulated conductors twisted, sheathed, or held together mechanically and not identifiable from each other in a common covering.

Twin Coaxial

A configuration containing two separate complete coaxial cables laid parallel or twisted around each other in one complex .

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 a replaced in parallel to each other.

Twinner

A device for twisting together two conductors.

Twisted Pairs

Any three individually insulated conductors which are twisted together.
   
U

UF

Thermoplastic underground feeder and branch circuit cable.

UHF

Abbreviation for ultra high frequency, 300 to 3,000 MHz.

UL

An abbreviation for Underwriters' Laboratories, a non-profit independent organization, which operates a listing service for electrical and electronic materials and equipment. (Canadian counterpart is CSA).

Unbalanced Circuit

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

Unbalanced Line

A transmission line in which voltages on the two conductors are unequal with respect to ground.

Unidirectional Concentric Stranding

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

A conductor with more than one layer of helically laid wires with the direction of lay and length of lay the same for all layers.

Unilay Strand

A conductor constructed with a central core surrounded by more than one layer of helically-laid wires, with all layers having a common length and direction of lay.

Unilay Stranding

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

USE

Underground service entrance cable.

UTE

Approval agency for France; Union Technique de l'Electricite.
   
V

V W-1

A flammability rating established by Underwriters Laboratories for wires and cables that pass a specially designed vertical flame test (formerly designated FR-1).

Valley

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

VDE

West Germany approval agency.

Velocity of Propagation (VP)

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.

VHF

Abbreviation 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.

Voice Frequency

Any of the frequencies that are audible to the human ear. For telephone transmission the range is generally from 300 to 3,400 Hz.

Volt

The standard unit of electromotive force or electrical pressure. One volt is the amount of pressure that will cause one ampere of current to flow through one ohm of resistance.

Voltage

The term most often used in place of electromotive force, potential difference or voltage drop to designate the electric pressure that exists between two points and is capable of producing a current when a closed circuit is connected between two points.

Voltage Breakdown

Test to determine voltage at which insulation fails at a given temperature and time.

Voltage Drop

The voltage developed across a component or conductor by the current in the resistance or impedance of the component or conductor.

Voltage Rating

(1) The highest voltage that can be continuously applied to a wire in conformance with the standard or specification; ( 2) The system voltage printed on the wire or cable.

Voltage Standing Wave Ratio (VSWR)

The ratio of the maximum effective voltage to the minimum effective voltage measured along the length of a mismatched radio frequency transmission line.

Volume Resistivity

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

VSWR

Abbreviation for volume standing wave ratio.

Vulcanization

A chemical reaction in which the physical properties of an elastomer are changed by reacting it with sulfur or other crosslinking agents.

Vutron

General Cable-Carol Cable trade name for a rubber compound with specific performance characteristics.

VW-1

A flammability rating established by Underwriters' Laboratories for wires and cables that pass a specially designed vertical flame test, formerly designated FR-1.
   
W

Wall Thickness

The thickness of the applied insulation or jacket.

WAN (Wide Area Network)

A network spanning a broad geographical area, providing data communications between computers and peripherals and switching equipment.

Water Absorption

Ratio of the weight or water absorbed by a material to the weight of the dry material.

Waterblocked Cable

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

Watertight Cable

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

Watt

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 D.C. circuit.

Wave Form

A graphical representation of a varying quantity. Usually, time is represented on the horizontal axis, and the current or voltage value is represented on the vertical axis.

Wavelength

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

Wetting

The ability of a material to absorb moisture .

Wicking

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

Wire

(1) A single piece of slender, flexible metal ranging in approximate size from a piece that is difficult to bend by hand to a fine three a d ; (2) Several wires (as in 1) twisted together; (3) Wires (as in 1 or 2) that are insulated.

Wire and Cable Marker

Identification marking of wire and cable.

Wire and Cable Tying, Clamping, and Harnessing Devices

Tying tapes, lacing cords, and flexible sleevings which are used for wire and cable bundling, harnessing, and holding. Other devices include plastic ties or clamps, spiral-cut plastic tubing, and plastic U-shaped trays or ducts.

Wire and Lead Cutters

Tools for cutting range from plier type cutters to semiautomatic or fully automatic machines integrated with other wire processing operations such as stripping, forming, and terminating.

Wire Gauge

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

Wire Nut

A closed end splice that is screwed on instead of crimped.

Wire Wrapped Connection

A solderless connection made by wrapping bare wire around a square or rectangular terminal with a power or hand tool.

Wire Wrapping Tools

Portable electric tools and automatic stationary machines used to make solderless wrapped connections of wires to terminals.

Wiring Closet

An enclosed space for housing telecommunications equipment, cable terminations, and cross-connect cabling. The closet is the recognized location of the cross-connect between the backbone and horizontal facilities.

Work Area (Work Station)

A building space where the occupants interact with telecommunications terminal equipment.

Working Voltage

(1) The highest voltage that can be continuously applied to a wire in conformance with the standard or specification; ( 2) The system voltage printed on the wire or cable.

Wrapper

An insulating barrier applied as a sheet or tape wrapped around a coil periphery.
   
X

XHHW

Heat and moisture resistant cross linked polyethylene insulated building wire, 75°C wet.

XHHW-2

Heat and moisture resistant cross linked polyethylene insulated building wire, 90°C wet or dry.

XLP

Crosslinked polyethylene.

XLPE

Crosslinked polyethylene.
   
Y

Yield Strength

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

Zero-Dispersion Wavelength

Wavelength at which the chromatic dispersion of an optical fiber is zero. Occurs when waveguide dispersion cancels out material dispersion.

Zytel

DuPont's trade name for nylon resins

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