Electrical insulator is a very important component in the electric power systems such as sub-stations

and distribution & transmission lines. In-depth study and practical knowledge on this subject is

necessary for the electrical professionals in the electrical power field. In the early days, insulators

were made of ceramic and glass materials. But in 1963, polymeric insulators were developed and its

improvements in design and manufacturing in the recent years have made them attractive to utilities.

It is consist of a fiberglass core rod covered by weathersheds of skirts of polymer such as silicone

rubber, polytetrafluoroethylene, EPDM (ethylene propylene diene monomer) and equipped with

metal end fittings. It is also called composite insulators, which means made of at least two insulating

parts – a core and housing equipped with end fittings. Polymeric insulators have many advantages

over the ceramic and glass insulators such as good performance in contaminated environment, light

weight, easy handling, maintenance free, and considerably low cost etc. Because of these properties it

is gaining popularity worldwide and replacing the conventional ceramic and glass insulators.