Cable construction

Tests on Cable Constructions. The Association of Edison Illumination Companies (AEIC) has approved an accelerated cable hfe test in which typical underground distribution power cables can be statistically compared based on their resistance to water treeing (number of days to fail). The comparison can be made by varying the type of insulation and/or other cable layers in an environment that contains hot water (90°C) under 8V/fi (200 V/mil) voltage stresses (four times the typical power cables operating voltages). 

The other approach to the reduction of the power loss to the dielectric material is by reducing the amount used. This is done by replacing part of the dielectric by air, an inert gas, or by vacuum. As examples there are three cable constructions in common use which employ these approaches to minimize dielectric loss. The first is the use of a foamed dielectric PS plastic that is commonly used in either twin lead transmission lines or in coaxial cables used for antenna lead-in wires in the UHF-TV antenna applications. The second system, which is illustrative of several sectional spacers, is used widely in communications cables of the coaxial type to minimize losses to the dielectric by reducing the amount of dielectric material in the cable. 

Conduct preliminary assessment of material cable construction options... 

Within that framework, the most effective constructions to meet existing requirements have been developed based on a variety of polymers including poly(vinyl chloride) (PVC), polyolefins, silicones, and fluoropolymers. Researchers are continually striving to develop more cost-effective compositions and cable constructions to enable replacement of more expensive materials with less expensive ones. In some cases, OEMs, cable manufacturers, and material suppliers are working to pass new standards that allow for substitution of new classes of materials or designs. 

The UL 1685 tray cable burn test was conducted on a cable construction with three different jacketing materials consisting of EVA polymer with 60 wt % Mg(OH)2 (EVA-MH), EVA polymer with 58 wt % Mg(OH)2 and 2wt % nanoclay (EVA-MH-NanoM), and 1 1 EVA PE with 58 wt %... 

Fluoropolymers are another class of material that finds utility in wire and cable constructions due to high service temperatures, chemical resistance, dielectric performance, and inherent flame retardancy. 

The single largest application for ECTEE has been as primary insulation and jacketing [62] for voice and copper cables used in building plenums [63]. In automotive applications, ECTEE is used for jackets of cables inside fuel tanks for level sensors, for hookup wires, and in heating cables for car seats. Chemically foamed ECTEE is used in some cable constructions [64]. In the chemical process industry, it is often used in chlorine/caustic environment in cell covers, outlet boxes, lined pipes (Eigure 4.26), and tanks. 

Cable Construction. A typical power cable consists of several concentric layers ... 

Herco x Plasticizer. [Aqualon] Pen-taerythritcri ester plasticizer for PVC used for wire insulatitm, government specification cable construction and liigh-quality plastisol ftHiiuilations. 

The following tables of current ratings are typical for the cable constructions and service voltages given. There are many tables available in the international standards e.g. BS7671, which is... 

IEC60092-3 Part 1 Cables (construction, testing and installations). 

A Giude to Wire and Cable Construction. American Insulated Wire Corp., GWC/5-01 Rev. 2. 

Cellophane is used as a general protective wrapping material. Because of its good electrical properties, it is used in wire and cable construction and other electrical products. It also functions as a separator, barrier, or release film in plastic molding and lamination. To make it moisture proof, most of the cellophane film is coated with a lacquer composed of nitrocellulose, plasticizers, resins, and waxes. This coating can also give the cellophane film a heat-sealing property. 

Note The intent of this table is to provide a simple comparison for various basic cable constructions. Special cable designs, including those employing exotic materials, can show an improvement over standard products in one or more categories... 

Lossy cable A coaxial cable constructed to have high transmission loss so it can be used as an artificial... 

The other approach to the reduction of the power loss to the dielectric material is by reducing the amount used. This is done by replacing part of the dielectric by air, an inert gas, or by vacuum. Figure 16-4 shows three cable constructions in common use which employ... 

The plant layout of the 4S is optimized to meet various functional needs the requirements for safety, radiation zoning, and piping and cabling construction requirements and access and security considerations. The general philosophy of the 4S plant layout is as follows ... 

For the first five years of its life, KYNAR pvdf was used primarily in the electrical and electronic markets. The product proved to have just the right combination of properties for insulation of computer wiring, and jacketing on cable constructions used in the military and aerospace applica-tions-... 

This new copolymer compared to PVDF is impact modified and specifically designed for use as a jacket material in wire and cable construction requiring higher flexibility and improved resistance to impact. As shown in Table 2, KYHAR FLEX 2800 has a lower melting point and a flexural modulus that is about one-half of the modulus of the homopolymer. KYNAR FLEX 2800 has a significantly higher notched impact strength when compared to the homopolymer. ... 

Vexler, G. Comibert, J. (Nordx Cdt., Inc.). Flame retardant dnal insulation design and cable construction for plenum applications. Can. Patent CA2421440, Sept. 10, 2004. 

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