Glossary of Wire Terminology

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A Top

A
Common abbreviation for ampere.

Abrasion Resistance
Ability of material or cable to resist surface wear.

AC
Alternating current (See alternating current).

Accelerated Aging
A test performed on material or cable meant to duplicate longtime environmental conditions in a relatively short amount of time.

Acceptance Test
Made to demonstrate the degree of compliance with specified requirements.

ACSR/GA
Aluminum conductor, steel reinforced, using Class A zinc coated steel wire.

ACSR/GB
Aluminum conductor, steel reinforced, using Class B zinc coated steel wire.

ACSR/GC
Aluminum conductor, steel reinforced, using Class C zinc coated steel wire.

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

Administrative Authority
An organization exercising jurisdiction over the National Electrical Safety Code.

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

Aging
The irreversible change of material properties after exposure to an environment for an interval of time.

Alternating Current
An electrical current that continually reverses its direction giving a definite plus and minus wave form at fixed intervals.

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

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

Ambient Temperature
Any all-encompassing temperature within a given area.

American Wire Gauge
A standard used in the determination of the physical size of a conductor determined by its circular mil area. Usually expressed as AWG.

Ampacity
The rms current which a device can carry within specified temperature limitations in a specified environment: dependent upon, (a) temperature rating, (b) power loss, (c) heat dissipation.

Ampere
The unit used for measuring the quantity of an electric current flow. One ampere represents a flow of one coulomb per second.

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

ANSI
American National Standards Institute

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

Approved
(1) Acceptable to the authority having legal enforcement. (2) Per OSHA: a product that has been tested to standards and found suitable for general application, subject to limitations outlined in the nationaly recognized testing lab's listing.

ASTM
American Society for Testing and Materials

AWG
American Wire Gauge, formerly known as Brown & Sharpe Gauge, based on the circular mil system. 1 mil equals .001.

B Top

B+S
Brown and Sharpe wire gauge, same as AWG.

Backfill
The materials placed to fill and excavation, such as sand in a trench.

Bare Conductor
A conductor having no insulation or jacket.

Bend Radius
A term used to denote the minimum radius that an insulated cable may be safely bent during installation and use. A bend radius value is usually expressed as a whole number multiple (i.e. 6X) of a cables overall diameter.

Binder
Usually a spirally served tape cord or thread used for holding assembled cable components in place awaiting further manufacturing operations.

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

Breaking Strength
The maximum load that a conductor attains when tested in tension to rupture.

BSC
Bare soft copper, uncoated annealed copper.

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.

Bunch-stranded Conductor
A conductor composed of wires twisted together with a given length and the direction of lay in such manner that the respective wires at successive cross sections along the length of the conductor do not necessarily form a symmetrical geometric pattern, nor necessarily occupy the same positions relative to each other.

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

Butt Splice
A splice where in the opposite ends of two wires butt against each other, or against a stop, in the center of the splice.

C Top

C Symbol
Designated for: capacitance, bias supply and centigrade.

Cable
An insulated conductor or twisted group of conductors used for the transmission of electrical energy.

Cable Assembly
A completed cable and its associated hardware.

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

Cable Jacket
See Sheath

Cable Sheath
See Sheath

Cabling
The act of twisting together two or more insulated components by machine to form a cable.

Capacitance
The ratio of the electrostatic charge on a conductor to the potential difference between the conductors required to maintain that charge.

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

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

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

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

Circuit
A completed path, over which electrons can flow, from the negative terminal of a voltage source to the positive terminal of the same voltage source.

Circuit Size
A term commonly used for wire sizes 18 AWG thru and including 10 AWG.

Circular Mil
The area of a circle one one-thousandth of an inch in diameter. Used in determining the cross-sectional area of a wire.

CMA
Circular Mil Area

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

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

Combination Stranded Conductor
A conventional concentric conductor in which the wires in the outer layer are larger in diameter than the wires in the inner layer or layers and the diameters of the all wires are within plus and minus 5 percent of the nominal wire diameter for the same size non-combination stranded conductor.

Compact Stranded Conductor
A unidirectional or conventional concentric conductor manufactured to a specified diameter, approximately 8 to 10% below the nominal diameter of a non-compact conductor of the same cross-sectional area.

Composite (Clad) Wire
A wire having a core of one metal to which is fused an outer layer or shell of one ore more different metals.

Compound
A term used to designate an insulating and jacketing material made by mixing two or more ingredients. To compound the mixing together of two or more different materials to make one material.

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

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

Concentric 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. When more than one layer is present each layer must have a different lay length.

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

Conductance
A measure of the ability of a conductor configuration to conduct an electrical charge. Conductance is a ratio of the current flow to the potential difference causing the current flow. It is the reciprocal of resistance.

Conductivity
A term used in describing the capability of a material to carry an electrical charge. Usually expressed as a percentage of copper conductivity - copper being one hundred percent (100%). Conductivity is expressed for a standard configuration of conductor.

Conductor
Any material capable of carrying an electrical charge easily. The most common materials for wire and cable applications are aluminum and copper (bare or coated).

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

Conduit
Typically a tube for protecting electrical wires or cables. It may be solid or flexible, metallic or non-metallic.

Continuity Check
A test performed on a length of wire or cable to determine if the electrical current flows continuously throughout the length.

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

CPS
Cycles per second, this is an obsolete designation and is now called Hertz (Hz). The SI unit is the Hertz, one cycle per second.

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

Cross-Linked
Intermolecular bonds produced between long chain molecules in a material to increase molecular size by chemical or electron bombardment means, resulting in a change in physical properties in the material - usually improved properties.

CSA
Canadian Standards Association

CT
Cable tray frame rating

CU
Copper

Current
The rate of transfer of electricity usually expressed in amperes.

Current Carrying Capacity
The current a conductor of a given size is capable of carrying safely without exceeding its own insulation and jacket temperature limitations.

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

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

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

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

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

D Top

D.C.
Direct current

D-C
Direct current

DCR
Direct current resistance

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

Dielectric
An insulating material usually having a very low loss factor.

Dielectric
absorption The storage of charges within an insulation; evidenced by the decrease of current flow after the application of dc voltage.

Dielectric Breakdown
Any change in the properties of a dielectric that causes it to become conductive. Normally the failure of an insulation because of excessive voltage.

Dielectric Constant
That property (K) of an insulating material which is the ratio of the parallel capacitance (C) of a given configuration of electrodes with the material as the dielectric, to the capacitance of the same electrode configuration with a vacuum as the dielectric.

Dielectric Strength
A term used to describe the limit, without damage of an insulating material, to an applied voltage potential.

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

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

Direct Current
An electrical current that flows in one direction only.

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

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

DOD
Department of Defense, part of the U.S. government executive branch that handles military matters, including data communications; responsible for some LAN associated protocols and standards such as TCP/IP.

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

Duct
An underground or overhead tube used for carrying electrical conductors.

E Top

E
Voltage, electromotive force

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 center displacement of one circle within the other.

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

Electro Motive Force
That force which determines the flow of electricity; a difference of electric potential.

Electrolytic Tough Pitch
A term describing the method of raw copper preparation to ensure a good physical and electrical grade copper finished product.

EMT
Electrical Metallic Tubing

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

Environment
(1) the universe within which a system must operate (2) all the elements over which the designer has no control and that affect a system or its inputs and outputs.

EPA
Environmental Protection Agency, the federal regulatory agency responsible for keeping and improving the quality of our living environment - mainly air and water.

ETL
Electrical Testing Laboratory

F Top

F
Fahrenheit

FAA
Federal Aviation Association

Farad
A unit of electric capacity.

Fault Ground
A fault to ground.

FCC
Federal Communications Commission

Fixture Wire
According to the National Electric Code, fixture wires are designed for installation in lighting fixtures and in similar equipment where the wires are enclosed and/or protected and are not subject to bending or twisting. Fixture wire shall not be smaller than #18 AWG. Although flexible stranding is used for most fixture wire, solid conductors can be used in some applications.

Flex Life
Ability of a conductor, wire or cable to withstand repeated bending.

Flexibility
The ease with which a wire or cable can be bent.

G Top

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

Galvanized Steel Wire
Steel wire coated with zinc.

Gateway
A special node that interfaces two or more dissimilar networks, providing protocol translation between the networks.

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

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

Ground
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.

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

Grounded Neutral
Neutral wire that is mechanically connected to ground.

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

H Top

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

Hash Mark Stripe
A noncontinuous, helical stripe applied to a conductor for circuit identification.

Hazardous Location
Ignitable vapors, dust, or fibers that may cause fire or explosion as defined by the NEC.

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

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

Hertz (Hz)
Cycles per second. A cycle that occurs once every second has a frequency of 1 hertz. The bandwidth of the average phone line is between 300 and 3000 cycles per second.

Hipot
DC high potential testing of medium and high voltage cables.

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.

Hygroscopic
The property of a material to absorb moisture from the air.

I Top

IACS
International Annealed Copper Standard

IAEI
International Association of Electrical Inspectors

ICEA
Insulated Cable Engineers Association

ICEA S-95-658-1999
Standard for nonshielded power cables rated 2000 volts or less for the distribution of electrical energy covers THHN/THWN, XHHW and RHH/RHW/USE cables

ID
Internal Diameter

IEEE
Institute of Electrical and Electronic Engineers

IMC
Intermediate Metal Conduit

Impedance
The ratio of the effective value of the potential difference between two terminals to the effective value of the current flow produced by that potential difference.

Inductance
That property of an electrical circuit by virtue of which a varying current induces an electromotive force in that circuit, or in an adjacent circuit.

Insulation
A non-conductive material usually surrounding or separating two conductive materials.

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

Interstice
In cable construction, the space, valley or void left between or around the cable components.

IR
Insulation resistance

ISO
International Organization for Standards

J Top

Jacket
A non-metallic covering over a wire insulation or an assembly of components. An overall jacket on a multiconductor cable is also often referred to as a sheath.

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

K Top

K
Constant used to denote insulation resistance.

KCM
1000 circular mils

Kilocycle
A term denoting 1000 cycles.

Kilohertz
A term denoting one thousand cycles.

Kilovolt
A term denoting one thousand volts.

Kilowatt
A term denoting one thousand watts.

KV
1000V

KVA
Kilovolt amperes (1000 volt x amperes).

KW
Kilowatt-1000 watts power.

KWH
Kilowatt hours (1000 watt hours).

L Top

Lay
Often referred to as pitch. The position of a helical element (conductor) of a cable in the axial length of a turn of the helix of that element.

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

LS
Low smoke

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

M Top

MCM
Thousand circular mils; e.g. 500 MCM is 500,000 circular mils.

Megohmmeter
An instrument used to measure insulation resistance (Readings are in megohmes).

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

MFT
Abbreviation for one thousand fee.t

MHO
An electrical unit of conductivity, being the conductivity of a body with the resistance of one ohm.

Mho
An electrical unit of conductivity, being the conductivity of a body with the resistance of one ohm.

MIL
Abbreviation for military as in military specification for wire or cable products.

Mil
One one-thousandth of an inch (.001). A unit used in measuring the diameter of a wire of the thickness of an insulation over a conductor.

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

Multi-conductor
More than one conductor within a single cable complex.

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

N Top

NEC
National Electric Code

NEMA
National Electrical Manufacturers Association

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

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

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

O Top

OD
The overall diameter of a cable, including conductor(s), insulation(s), jacket (if used) and concentric neutral (if used).

OEM
Original Equipment Manufacturers

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.

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

OSHA
Occupational Health and Safety Administration

OSHA Occupational Safety and Health Act 1970
Administered by U.S. Dept. of Labor which establishes Standards and safety requirements which all businesses must meet.

Overall Diameter
The finished diameter of a wire of cable.

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

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

P Top

Peak Voltage
The maximum instantaneous voltage.

Percent Conductivity
The conductivity of a material expressed as a percentage of that of copper.

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

Pitch Diameter
The diameter of a circle passing through the center of the conductors in any layer of a multi-conductor cable.

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 the power to the effective values of the electromotive force multiplied by the effective value of current in volts and amperes respectively. The cosine of the angle between voltage applied and the current resulting.

PSI
Pound per square inch.

PVC
Polyvinyl Chloride

R Top

Rated Temperature
The maximum temperature at which an electric component can operate for extended periods without the loss of its basic properties.

Rated Voltage
The maximum voltage at which an electrical component can be operated for extended periods without undue degradation or safety hazard.

Reactance
That part of the impedance of an alternating current circuit which is due to capacitance or inductance.

Resistance
The property of an electric circuit which determines for a given current the rate at which electric energy is converted into heat and has a value such that the current squared multiplied by the resistance gives the power converted.

RHH
Rubber-insulated, heat-resistant building wire, 90°C dry locations, now allowed to be cross-linked polyethylene insulated.

RHW
Rubber-insulated building wire, heat and moisture-resistant, 75°C wet or dry locations, now allowed to be cross-linked polyethylene insulated.

Round Wire
A wire circular in cross section as opposed to flat, square, etc.

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

S Top

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

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

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

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

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

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

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

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

SIC
Specific inductive capacitance. Same as Dielectric Constant.

Solid Conductor
A conductor consisting of a single wire.

Spark Test
A test designed to locate pinholes in an insulated wire by application of an electrical potential across the material for a very short period of time while the wire is drawn through an electrode field.

SPC
Submersible pump cable

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.

Square Mil
The area of a square one mil by one mil.

Strand
A single uninsulated wire.

Strand Lay
The distance of advance of one strand of a spirally stranded conductor, in one turn, measured axially.

Stranded Conductor
A conductor composed of a group of wires, or of any combination of groups of wires.

T Top

Tank Test
A term used to describe a voltage dielectric test where the specimen to be tested is submerged in a liquid (usually water) and a voltage potential applied between the conductor and liquid as ground.

TC
Tray cable, per Art. 340 of the NEC.

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

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

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

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

Tensile Stress
Force per unit cross sectional area applied to elongate a material.

TFFN
Fixture wire, thermoplastic-covered with flexible stranding and nylon sheath, 90°C dry.

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

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

Thermal Resistivity
Thermal resistance of a unit cube of material.

Thermal Shock
The resulting characteristics when a material is subjected to rapid and wide range changes in temperature in an effort to discover its ability to withstand heat and cold.

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

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

THHN
Thermoplastic insulated, high heat resistant, nylon jacketed cable, 90°C dry location, 75°C wet location.

THW
PVC insulated building wire. Flame-retardant, moisture and heat-resistant, 75°C. Dry and wet locations.

THWN
75°C, 600V nylon jacketed PVC insulated building wire. For wet and dry locations.

THWN-2
Same as THWN with 90°C dry, 90°C wet location.

U Top

UF
Underground feeder cable, thermoplastic insulated 60°C wet or dry locations.

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

UL
Underwriters Laboratory. Standards and tests that wire must meet in order to receive UL approval.

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

Unidirectional Concentric Stranding
A unidirectional stranding wire 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 conductor stranding configuration in which all layers have the same 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, rubber insulated, neoprene jacketed, 75°C wet location.

USE-2
Same as USE except 90°C wet rating.

V Top

Volt
A unit of electromotive force.

Voltage
The term most often used to designate electric pressure that exists between two points and is capable of producing a flow of current when a closed circuit is connected between the two points.

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

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

VW-1
Underwriters Laboratories vertical wire flame test applicable to single conductor wires and cables (formerly FR-1).

W Top

W/O/G
Without ground.

Wall Thickness
A term expressing the thickness of a layer of applied insulation or jacket.

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

Watt
A unit of electrical power; the power of one ampere of current pushed by one volt of electromotive force.

WC8-1974
Same as ICEA S68-516

WC 70
Same as ICEA S-95-658-1999

Wire
Wire can be divided into two areas: 1. A slender rod or filament of drawn metal; 2. A rod of drawn metal filament covered with insulation. These can be classified as drawn metal wire and insulated wire respectively.

X Top

XHHW
600V cross-linked polyethylene (XLP) insulated building wire. 90ºC for dry and damp locations, and 75ºC for wet locations.

XHHW-2
600V cross-linked polyethylene (XLP) insulated building wire. 90ºC dry, 90°C wet.

XLP
Cross-linked polyethylene

XLPE
Cross-linked polyethylene