Post Insulators are made of epoxy resin with threaded inserts made of aluminum alloy. The casting methods we use guarantee products with excellent electrical and mechanical properties and constant quality.

These insulators have been specifically designed so as to withstand the demands made upon them by extremes in climatic conditions and weather fluctuations. The post insulator flanges are sharp and narrow which results in shape and creepage distance most suitable for countering problems of pollution. The insulators may be cleaned using water, spirit, petrol or toluene. Even strong arcs fail to break the cast resin post insulators. Scars in the surface caused by flash-over can be easily made good by smoothing and cleaning the marks and rubbing a thin layer of silicone paste into the surface. This treatment does not decrease the flashover strength of the insulator. The cast resin post insulators also have a high resistance to chemicals.

The insulators can be used in areas where the atmosphere includes large quantities of corrosive gasses such as sulphuric and nitrogenous compounds. Indoor post insulators can be installed in any chosen position. The operating position of outdoor post insulators can vary from vertical to horizontal. Aluminum compound busbar clamps are used for fixing busbars to post insulators. The dimensions and position of the busbar stack and the type of insulator used, determine the type of busbar clamp. The dimensions of the busbars have been calculated so that if the height of the busbar stack does not exceed the width of the busbars they will withstand greater mechanical strain than the corresponding support insulators.

National Switchgears is manufacturer & suppliers of Post Insulators.