overhead line, line support

Wooden poles are made of woods. this type of poles are used for shorter spans up to 50 meters. These are mainly used in rural areas.

For low voltage line less than 11KV shackle insulators are used as strain inhalators. this is also known as spool insulators. it is used in low voltage distribution lines. Such insulators can be used either in a horizontal position or in a vertical position. They can be directly fixed to the pole with a bolt or cross arm. The conductor in the groove is fixed with soft binding wire.

This poles are used generally for the distribution purpose in the city areas it has high mechanical purpose in the city areas. It has high mechanical strength with longer life poles.

These poles are very popular in recent days. They provide longer span than steel and wood poles. They have greater mechanical strength with conger life. These type of pole require low maintenance it has good insulating properties.These poles are heave weights. So the cast of transportation is high.

For long distance transmission at higher voltage steel towers are used. These steel towers have longer life, great mechanical strength. It is suitable for severe climate condition these type of steel towers are used for conger spans. Tower footings are grounded by driving rods in to the earth. This minimizes the lightning troubles as each tower acts as a lightning conductors it can also used as double circuit tower which allow continuity of supply in case of one circuit break down.

An electrical insulator is a material whose internal electric charges do not flow freely.In overhead transmission or distribution lines insulators are used to insulate the current flowing in the conductor to earth through the poles or towers.The most commonly used materials for insulator of over head line is porcelain.

This type of insulator is popularly used in power network up to 33kv system. The pen type insulator is secured to the cross arm on the pole. The live conductor attached to the top of the pen insulator the shortest distance between conductor and earth, surrounding the insulator body along which electrical discharge may take place through air is known as flash over distance.

In this type of insulator number of insulators are connected in series to form a string and the line conductor is carried by the bottom most insulator.

When there is a dead end of the line or there is a sharp carve the line is subjected to greater tension. In order to relive the line of excessive tension, these insulators are used.

For low voltage range lines, the stays are to be insulated from ground at a height. Stay Insulator This insulator used in the stay wire is called as the stay