[FS-66/5, FS-110/8 Composite crossarm insulators] Overview: composite insulators is a special insulation controls, can play an important role in the overhead power transmission lines. [FS-66/5, FS-110/8 Composite crossarm insulators] advantage umbrella of the umbrella insulators is to use one of the oldest suspension insulator, he is characterized by structural shapes simple, low cost, suited Clean area choose to use. They are typically used in the exchange of transmission lines. Bell-type suspension insulator porcelain insulator early years used for poles, with the development of science and technology, and slowly developed in the high-pressure end of the wire connecting the tower to hang a lot of disk-shaped insulator, it is to increase the creepage distance, usually made of glass or ceramic, called insulators. Insulators for overhead transmission line plays two fundamental role, namely support wires and prevent current back ground, these two actions must be guaranteed, the insulator should not change because of various electrical and mechanical stress caused by environmental and electrical load conditions occur and fail, Otherwise, it will not have a significant insulator effect, it will damage the use and operation of the entire line of life [FS-66/5, FS-110/8 Composite crossarm insulators] classification of composite insulators can be divided into: line composite insulators and power stations electrical composite insulator. Can be divided into Rod Composite insulators, pin composite insulator, cross arm composite insulator, pillar composite insulators, composite insulators and other partial wind. [FS-66/5, FS-110/8] transmission line insulators parameters: AC transmission lines with a voltage composite insulators 10--1000kV rated mechanical load 70-550kN DC transmission lines with a voltage composite insulators ± 500-- ± 800kV [FS-66/5, FS-110/8] Composite crossarm insulators conditions: 1, ambient temperature -40 ℃ ~ 40 ℃ 2, no more than 1500 meters above sea level 3, AC power frequency is not over 100HZ 4, maximum wind speed does not exceed 35m / s 5, earthquake intensity is not more than eight