Insulators for overhead lines

The insulators are used for the electric insulation and mechanical fastening of the parts of  electric devices which are being under different potentials. They are distinguished as insulation devices of low (up to 660 V) and high (higher 660 V) voltage. High voltage insulators (high voltage) are manufactured for 1, 3, 6, 10, 20, 35, 110, 150, 220, 330, 500, 750 and 1150kV.

 

Insulators for overhead lines (high-voltage insulators) play the important and responsible role in processes of distribution and transfer of the electric power. By purpose and design they are classified as post, bushing and suspension insulators. According to the type of installation they are divided  for internal and external installation.

 

 Post insulators for internal installation are manufactured for the voltage of 10 - 35 kV, for external installation – for 10 - 110 kV.

 

Bushing insulators are intended for carrying out of the conductors through the earthed body of devices, walls and ceiling of the buildings and are issued for nominal voltages up to 35 kV. Bushing insulators for 110 kV and higher have received the names of linear or apparatus inputs depending on purpose of usage.

 

 There are the cap and pin and longrod devices among the suspension insulators for overhead lines (high-voltage) intended for voltages from 35 up to 1150 kV.

 

According the material the insulators for overhead lines can be produced from electro technical porcelain, glass or composite materials.