Electric cables. Typology
Following the previous post in which we focus on the definition and composition of electrical cables, today we see their classification according to different criteria:
Following the previous post in which we focus on the definition and composition of electrical cables, today we see their classification according to different criteria:
An electrical cable is a conductor or set of them coated by an insulating or protective material, used to transport electrical energy, generally.
The best conductor of electricity is silver. However, due to its high price, it is usually used copper or aluminum. The latter, although it has an electrical conductivity of 60% compared to copper, is more economical and lightweight. So, it is ideal for overhead transmission lines for electricity in high voltage networks.
The applications of halogen-free cables are provided in the Low Voltage Electrotechnical Regulations (REBT), which are called “wire HS” or “High Security”.
They are safe wires because their insulation do not contain any chemical element of group 17 of the periodic table, that is to say, neither fluorine nor chlorine nor bromine nor iodine and nor astatine. All of them are elements so reactive that they are never found in nature without mixing with others. The result of the combustion of materials of this type is a large amount of corrosive, toxic and opaque smoke. Therefore, the halogen-free cables, in case of fire, are much better behaved than, for example, PVC (it contains chlorine).
UNE 21089 regulates the color of conductors insulation, to differentiate when handling, because each wire has got a role. Therefore is not an aesthetic issue. Thus, the regulation states:
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