Electrical Glossary


Common abbreviation for ampere


Multiple Definitions:

  1. see Alternating Current
  2. see Armor Cable
Abrasion Resistance

Ability of material or cable to resist surface wear

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

Alternating Current

An electric current that reverses its direction at regularly recurring intervals


Brown and Sharpe wire gauge, same as AWG


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

Bare Conductor

Conductor having no insulation or jacket

C Symbol

Designated for: capacitance, bias supply and centigrade


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


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


Direct current


Direct current


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


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.


Voltage, electromotive force


British terminology for zero-reference ground.


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.




Federal Aviation Association


A unit of electric capacity.

Fault Ground

A fault to ground.


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

Galvanized Steel Wire

Steel wire coated with zinc.

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 3,000 cycles per second.


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.


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


International Annealed Copper Standard


International Association of Electrical Inspectors


Insulated Cable Engineers Association

ICEA S-95-658-1999

Standard non-shielded power cables rated 2,000 volts or less for the distribution of electrical energy covers THHN/THWN, XHHW and RHH/RHW/USE cables.


Internal diameter


Institute of Electrical and Electronic Engineers


Intermediate Metal Conduit


Insulation resistance


International Organization for Standards


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.


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


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

Insulation Resistance

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


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


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.


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.


Constant used to denote insulation resistance.


1,000 circular mils


1,000 volts


Kilovolt amperes (1,000 volt x amperes)


Kilowatt – 1,000 watts of power


Kilowatt hours (1,000 watt hours)


A term denoting 1,000 cycles


A term denoting 1,000 cycles


A term denoting 1,000 volts


Low smoke


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 element, in one turn measure axially.


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


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


Abbreviation for one thousand feet.


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


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


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


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

Melt Extrude

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


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


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.


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.


National Electric Code


National Electrical Manufacturers Association


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


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


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


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


Original Equipment Manufacturers


Occupational Health and Safety Administration

OSHA Occupational Safety and Health Act 1970

Administered by the U.S. Department of Labor, which established standards and safety requirements which all businesses must meet.


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


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

Overall Diameter

The finished diameter of a wire of cable


The current which causes an excessive temperature rise in conductor


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


Pound per Square Inch


Polyvinyl Chloride

Peak Voltage

The maximum instantaneous voltage

Percent Conductivity

The conductivity of a material expressed as a percentage of that of copper


A particular stage or point of advancement in an electrical cycle. The fractional part of the period through which the time has advanced measure 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 the current in volts and amperes respectively. The cosine of the angle between voltage applied and the current resulting.


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


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

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.


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


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.

Round Wire

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


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


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


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


Service round entrance cable (Type SE, Style R)


Service entrance cable (type SE, style U). Unarmored.


Specific inductive capacitance. Same as Dielectric Constant.


Submersible pump cable

Series Resistance

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


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


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


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.

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.

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


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.


Tray cable, per Article 340 of the NEC.


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


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


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


75°C, 600V, nylon-jacketed, PVC-insulated, moisture and heat-resistant, 75°C. Dry and wet locations.


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

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.

Temperature Coefficient of Resistivity

Then 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.

Thermal Rating

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

Thermal Resistance

The change in the electrical resistance of a material when subjected to heat. Resistance to the 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

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


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


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


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


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


Underground service entrance cable, rubber-insulated, neoprene-jacketed, 75° wet location.


Same as USE, except 90°C wet rating.

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.

Unilay Stranding

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


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


A unit of electromotive force.


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.


Without ground

WC 70

Same as ICEA S-95-658-1999


Same as ICEA S68-516

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.


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


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


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


600V cross-linked polyethylene (XLP) insulated buliding wire. 90°C dry and wet.


Cross-linked polyethylene


Cross-linked polyethylene

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