Glossary of Terms

 

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A Top of Page

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.

 

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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.

 

C Top of Page

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.

 

D Top of Page

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.

 

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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.

 

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F - Fahrenheit

FAA - Federal Aviation Association

Fard - A unit of electric capacity.

Fault Ground - A fault to ground.

 

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

Galvanized Steel Wire - Steel wire coated with zinc.

 

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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.

 

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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

 

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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 of Page

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).

 

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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.

 

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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.

 

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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.

 

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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.

 

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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

 

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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.

 

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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.

 

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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 - 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.

 

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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 of Page

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 of Page

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.

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

WC8-1974 - Same as ICEA S68-516

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 of Page

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