There is a wide range of products which are powering our today and tomorrow. There are a lot of types of power cables which are lighting our present. There is a large variety of power cables available on the basis of their utilization. For example: the power cables used for the small applications have the low strength and the power cables used for the major applications have the large strength. The selection of the material used for making the power cables can make the power transmission easier or complicated.
The power cables are usually made with copper or aluminium. Both aluminium and copper are very good conductors of the electricity. But the wires made of aluminium are 70% lighter than the copper wires. Aluminium wires are also generally inexpensive when compared to the copper wires. The copper power cable accessories are most commonly used for the electrical fitting of the buildings. The aluminium wires are mostly used for the overhead power transmission lines. The main advantage of copper is that it is more flexible than the aluminium. In the circuit of buildings “fuses” are used as a protection device and in the high power transmission lines the “lightning arrester” is used as a protection device for them.
A lightning arrester can be defined as an object which is used to protect the electrical systems and telecommunication systems to protect from the detrimental effects of the lightning. A distinctive lightning arrester consists of a high voltage terminal and a ground terminal. When a tide of the lightning energy travels through the main power line to the arrester, the power from the tide or surge is amused through the arrestor, in most cases to the Earth.
A ring is provided on the top of the arrester due to the purpose that it may collect the lightning from around. This ring is only provided in case when the Earth is not near the arrester. The terminal connecter is provided at the top of the lightning arrester. It is connected in parallel to the circuit. The inner shell is made up of MOV discs, which is a semiconducting material. The outer shell is provided with the bushings. These whole components are fitted or mounted on the diaphragm which is here for the release explosion. The MOV (metal oxide varistor) discs are made with the material called silicon carbide.
When the normal voltage is flowing through the lightning arrester, the MOV discs will work like a semiconducting material. But when the voltage more than the described voltage flows from it, the MOV disc will act like a pure conducting material. The diaphragm will get destroyed when the MOV discs act like a pure conducting material. The FRP (fibre glass reinforces plastic) rods are provided in the core of the lightning arrester for supporting the MOV discs. The FRP rods have high mechanical strength. If the lightning arrester is not provided in the equipment then, the lightning will directly strike on the earth due to which, the any person passing nearby that point will get a sudden shock and get easily burned. Therefore the lightning arrester manufacturer has to build it so much carefully because any kind of the failure of the lightning arrester will lead to the loss or crores and lakhs of rupees.