Thermax | Glossary

Cable - Either a stranded conductor with or without insulation and other covering (single-conductor cable), or a combination of conductors insulated from one another (multiple-conductor cable).

Cable Core - The portion of an insulated cable lying under the protective covering or coverings.

Cable Filler - The material used in multiple-conductor cables to occupy the interstices formed by the assembly of the insulated conductors, thus forming a cable core of the desired shape (usually circular).

Cable Sheath - The protective covering applied to cables.

Cabling - Twisting together two or more insulated conductors by machine to form a cable. This also is a term loosely applied to bundling of wires together such as in the forming of wire harnesses.

Cabling Factor - Used in formula for calculating the overall diameter of cable. D=fd where D=cable diameter, f=factor, and d=diameter of one conductor.

Capacitance (Capacity) - That property of a system of conductors and dielectrics which permits the storage of electricity when potential difference exists between the conductors. Its value is expressed as the ratio of a quantity of electricity to a potential difference. A capacitance value is always positive.

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

Cellular Insulation - Material in foamed form with the cells closed or interconnected.

Characteristic Impedance - Characteristic impedance of a uniform line is the ratio of an applied potential difference to the resultant current at the point where the potential difference is applied, when the line is of infinite length. Note that the term is applied only to a uniform line. A coaxial cable is such a uniform line. There are three main impedance groups in coaxial cable, namely, 50, 70, and 93 ohms.

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.

Circular Mil - A unit of area equal to the area of a circle whose diameter is 1 mil (0.001 inch); equal to square mil x 0.78540. Used chiefly in specifying cross-sectional areas of round conductors.

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

Coating - Plating surface of a conductor to prevent corrosion and facilitate soldering. One coating commonly used on copper wire is tin. Term can also apply to an insulating coating. junction of the two metals is continuously welded.

Coaxial Cable - A cable consisting of two cylindrical conductors with a common axis. The two conductors are separated by a dielectric. The outer conductor, normally at ground-potential, acts as a return path for current flowing through the center conductor and prevents energy radiation from the cable. The outer conductor, or shield, is also commonly used to prevent external radiation from affecting the current flowing in the inner conductor. The outer shield or conductor consists of woven strands of wire or is a metal sheath.

Coil Effect - The inductive effect caused by a spiral wrapped shield. This is more pronounced at higher frequencies.

Cold Bend - Test procedure 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 defects or deterioration in the materials or construction.

Cold Flow - Permanent deformation of materials due to mechanical force or pressure (not due to heat softening).

Cold Joint - Soldered joint made with insufficient heat.

Cold Work - Hardening and embrittlement of metal due to repeated flexing action.

Concentric - A central core surrounded by one or more layers of helically wound strands in a fixed round geometric arrangement. It is optional for the direction of lay for successive layers to be alternately reversed or in the same direction. If the direction of lay for successive layers is the same, the lay length shall increase with each successive layer. The standard direction of the outer layer is left hand.

Concentric-Lay Cable - Either: (a) A concentric-lay conductor as defined above, or (b) A multiple-conductor cable composed of a central core surrounded by one or more layers of helically laid wires. (Note: In the most common type of Concentric-Lay Conductor, all wires are of the same size and the central core is a single wire.)

Concentric Strand - A strand that consists of a central wire or core surrounded by one or more layers of spirally laid wires. Each layer after the first has six more strands than the preceding layer and is applied in a direction opposite to that of the layer under it.

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.

Conductance - The reciprocal of resistance. It is the ratio of current passing through a material to the potential difference at its ends.

Conductivity - Reciprocal of volume resistivity. Conductance of a unit cube of any material.

Continuity Check - A test performed on a length of finished wire or cable to determine if the electrical current flows continuously throughout the length. Each conductor may also be checked against each other to ascertain that no short exits.

Contrahelical - The direction of a layer with respect to the previous layer meaning a layer spiraling in an opposite direction than the preceding layer within a wire or cable.

Controlled Impedance Cable - Package of two or more insulated conductors where impedance measurements between respective conductors are kept essentially constant throughout the entire length.

Copolymer - A compound resulting from the chemical reaction of two chemically different monomers with each other.

Copper - Available in rod, sheet, foil, tube, and wire forms. On a volume basis, copper has the conductivity of the common (non-precious) metals. Copper and copper alloys offer excellent corrosion resistance, high thermal conductivity, and ease of fabricating, joining and forming. The strength to weight ratio of copper is relatively low and it loses strength at elevated temperatures. Copper is the most widely used electrical conductor in wires and cables. Some of the common types of electrical coppers and copper alloys are: Electrolytic tough pitch copper (ETPC) has a minimum copper content of 99.9%. Annealed conductivity averages 101% with a 100% minimum. It is widely used for wire and bus bars. Silver bearing copper with a 99.9% copper content provides nearly the same electrical conductivity as the ETP copper but offers a higher softening point, greater resistance to creep, and higher strength at elevated temperatures. Oxygen-free high-conductivity copper (OFHC) has 99.95% minimum copper content with an average annealed conductivity of 101%. This copper has no residual deoxidant. Other coppers use phosphorus, boron, or lithium as deoxidizers to eliminate susceptibility to hydrogen embrittlement and improve weld ability.

Copper-Covered Steel Wire - A wire having a steel core to which is fused an outer shell of copper.

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

Corona - A luminous discharge due to ionization of the gas surrounding a conductor around which exists a voltage gradient exceeding a certain critical value.

Corona Extinction - The voltage where corona, once initiated, will extinguish, while applying a decreasing voltage to the cable.

Corona Ignition Point - The voltage where corona will start, while applying an increasing voltage signal to the cable.

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

Coulomb - Unit quantity of electricity; i.e. the quantity transferred by one ampere in one second.

Crazing - Minute cracks on or near the surface of materials such as plastics.

Cross-Linking - The setting-up of chemical links between the molecular chains.

Cross-Sectional Area of a Conductor - The sum of the cross-sectional areas of its component wires, that of each wire being measured perpendicular to its individual axis.

Crosstalk - Signal interference between nearby conductors caused by the pickup of stray energy.

CSA - Canadian Standards Association.

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

Current Carrying Capacity - The maximum current a conductor can carry without heating beyond a safe limit.

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

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