Cable construction Insulation

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 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. 

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

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-... 

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

Figure A16.1 Different constructions of paper-insulated cables...

Wetted instrument parts and pockets generally in accordance with wetted plant items in applicable area. Transmitter housings generally coated as structural steelwork above or constructed from 304L stainless steel according to availability and life-cycle cost. Cable insulation to be PVC, and carbon steel conduit (coated in accordance with guidance above) to be employed throughout. 

Wire and cable insulation consumes 4% of all PVC with construction and automotive wires, electrical cord jacketing, fibre optic sheathing, heat-shrinkable sleeves. .. Components in phone systems, power tools, refrigerators, washing machines, air conditioners, computers, keyboards, housings. .. 

Asbestos fibers are found worldwide in many products as reinforcement in cement water pipes and the inert and durable mesh material used in filtration processes of chemicals and petroleum, for example. However, asbestos is not the only inorganic fiber in use today. Synthetic inorganic fibers abound. Glass fibers have replaced copper wire in some intercontinental telephone cables. Fiberglas (a trade name) has become the insulation material of choice in construction. Carbon and graphite fiber composites are favored materials for tennis racket frames and golf clubs. Fibrous inorganic materials have become commonplace in our everyday lives. 

Ethylenethiourea has a wide variety of uses in addition to vulcanization, a principal application since 1948. The curing process converts most of the ETU to other compounds, but traces of it are still found in the rubbers. Neoprene (polychloroprene) is found largely in automotive parts, wire and cable insulation, construction and adhesives. Consumer products containing neoprenes include container seals (e.g., aerosol dispensers) and shoes. It is also an intermediate in the manufacture of antioxidants, dyes, fungicides, insecticides, pharmaceuticals, synthetic resins, and a constituent of plating baths. 

Multi-layer insulation constructions are used. With the high-voltage cable, three separate layers may cover the center conductor. The innermost layer will function as an electric screen, the intermediate layer is usually a PE insulation material, and the outer layer serves as an electric screen. The processing technique can be used for primary and secondary coating where the covering is on metallic conductors or coating previously insulated wires. 

In studies where a knowledge of the diffusion of metallic ions in polymers is important, one often wishes to measure a profile of the concentration as a function of depth. Neutron activation cannot be used to measure these profiles directly, but if the sample can be cut into thin slices with a microtome, these can be analysed individually to construct the profile. In our laboratory this technique is used extensively to study the migration of ions into the polyethylene insulation of high-voltage cables (10). These impurities contribute to the degradation with use of the electrical properties of the cable. 

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