Insulator is a special kind of insulating control, which can play an important role in overhead transmission line. Early years insulator for more poles, slowly development in high type high voltage wires to hang a lot at the end of the disc insulators, it is to increase the creepage distance, usually made of glass or ceramic call insulator. Insulator should not change due to environmental and electrical load conditions lead to a variety of electrical and mechanical stress and failure, or else there won't have a significant role in the insulator, will damage the whole line of use and operating life.
At one end of the high voltage wire connecting tower hangs a number of disk insulators, which are designed to increase creepage distance, usually made of glass or ceramic, called insulators.
In order to prevent dust and other impurity in the adhered on the surface of the insulator, forming pathway was breakdown voltage on both ends of the insulator, namely creepage. Therefore, increasing the surface distance, namely the creepage distance, the distance along the surface of the insulating discharge the leakage distance call creepage distance. Distance = surface distance/high voltage system. According to different degree of filth, heavy polluted areas generally adopt the creepage distance is 31 mm/kv.
A zero-value insulator refers to an insulator with a potential distribution near zero or zero at both ends of the insulator.
Zero or low insulator: the influence of the insulation of the line conductor depends on the insulator string, due to manufacturing defect or role of the outside world, the insulation of the insulator performance will continue to degradation, when absolutely resistance lower or equal to zero is called low or zero insulator. We have to test the circuit, and the proportion of zero or low insulator was about 9%. This is our company another main cause of the high line lightning trip-out rate. Insulators are smooth and can reduce the resistance of wires to reduce current loss.
Maintenance and management
In wet weather, the dirty insulator is prone to flashover discharge, so it is necessary to clean up and restore the original insulation level. The general area is cleaned once a year and the polluted area is cleaned twice a year (before the fog season).
1. Power failure cleaning
The power cut is to wipe the worker's rod after the power failure. If wipe not net, can wipe with wet cloth, also can use scour scrubbing, if still scrubbed, should replace insulator or change synthetic insulator.
2. No power failure cleaning
It is usually used to brush or tie the insulator on the road line. The electrical properties and the effective length of the insulated rod, the distance between the person and the charged part shall be in accordance with the corresponding voltage grade, and the operation must be supervised by the special person.
3. Flush with charged water
There are two ways of flushing water and small water. Washing water, effective length of operation rod, distance between man and charged part must meet the requirements of industry regulations.
1. Insulators are usually divided into dielectric and unbreakable.
2. The structure can be divided into column type (pillar) insulator, suspension insulator, pin insulator, butterfly insulator, tension insulator and anti-pollution typeInsulator and casing insulator.
3. It is divided into line insulators and power stations and electrical insulators according to the application. There are pin type, butterfly shape, plate suspension, unbreakable type with horizontal and rod suspension. There are needle strut, hollow pillar and casing for the breakdown type insulator for power station and electric appliances, and the non-breakdown type has the rod and the container porcelain sleeve.
4. Insulators used in overhead lines, such as pin insulators, butterfly insulators, suspension insulators, porcelain crossers, rod insulators and tension insulators, etc.
5. The commonly used insulators are ceramic insulators, glass steel insulators, synthetic insulators and semiconductor insulators.