Electrical insulators include porcelain insulators, glass insulators and silicone insulators at present. Silicone insulators can be divided into 7 kinds, such as composite pin insulators, composite suspension insulators and so on.

What is an insulator?
Substance blocks or retards the flow of electrical current or heat. An insulator is a poor conductor because it has a high resistance to such flow. Silicone insulators break up the heat-flow path by absorbing radiant heat; include fiberglass, cork, and rock wool.

Silicone insulators application
Silicone insulators are commonly used to hold conductors in place, separating them from one another and from surrounding structures to form a barrier between energized parts of an electric circuit and confine the flow of current to wires or other conducting paths. Silicone insulators include composite pin type insulator, suspension insulator, line post insulator and so on according to application.

Silicone insulators arc requirement:
In service care must be given to protecting the end fittings of silicone insulators from the melting effects of power arc currents. If an arc is allowed to root on the end fitting of a silicone insulator, such as silicone rubber pin insulators, adjacent to the polymer coating, the heat of arc is likely to cause sufficient damage to allow water ingress. This will result in failure of the silicone insulator. Accordingly all silicone insulators should be fitted with carefully designed arc protection devices.

Relative Articles:
IEC BS 900mm creepage distance porcelain pin insulator
Composite polymer pin insulators medium voltage
Porcelain grey glazed pin insulator