Insulators are kept in electrical systems to prevent the flow of current to earth from its supporting points. The insulator material has very high resistance to the flow of current. In overhead lines are supported by the poles, which are grounded, the insulator is used to prevent the flow of current from the transmission lines to the ground through the poles supporting the transmission lines.
Properties any insulating material must have -
The insulating material must be strong enough to support the weight and tension of the conductors. Since, insulators are also used in high voltage systems; it must have high dielectric strength to withstand the voltage stress of high voltage systems. Another important quality of the insulator material is that it must give high resistance to the flow of current.
The insulating material should be free from any impurities and it must not have any opening through which any moisture or gases can enter through. At the same time, the electrical or physical properties of the insulating material must not change with the passing temperature
Types of insulators –
Porcelain insulators are the commonly used insulators for over head lines. Porcelain is basically aluminum silicate...This aluminum silicate is mixed with quartz, plastic, feldspar to get the final product. The surface Porcelain insulators manufacturers in Delhi of the porcelain material is so glazed that water cannot stand on it and also it is free from any porous or impurities.
Glass insulators are also being used in overhead transmission lines. The glass insulators have number of advantages over porcelain insulators. The glass insulators have high resistance to flow of current and their thermal co efficiency is low. The major benefit of using glass insulators is that they have longer life and are not affected by aging. However, they are vulnerable to heating and collecting dust and moisture.
Polymer insulator comes in two parts. One part is known as core part made and another is shed part that covers the core part. The core part is rod part and shed part is weather shed part. The shed part protects the rod part from weather conditions. The two extreme sides of the rod part have Lightning Arresters Manufacturers in Delhi galvanized cast steel ends. Polymer insulator is very light and very flexible to minimize the breaking chances. The light weight and smaller size has kept its installations cost low. However, the chances of moisture entering the insulator are also high due to any gap between rod and sheds.
No comments:
Post a Comment