Polymer Insulator (composite) is an electrical device consisting of insulation section made of polymer materials and metal fittings.

How it is made :

The insulation unit is made of fiberglass. The protective ribbed mold is made of silicon organic rubber. Flanges are made of anti-rust alloy thus providing safe long-term operation under various climatic conditions.

  • Insulation section – an element bearing mechanical and electric loads and consisting of insulation core unit covered with protective mold.
  • Insulation core unit – a rod made of composite dielectric substance – fiberglass, as a rule (tar reinforced with fiberglass) or consisting of separate elements assembled at the unit in a particular order.


  1. Simple maintenance. No necessity in washing of insulation during the entire service lifespan when mounted in recommended areas of pollution.
  2. Light weight (3-5 times lesser than the porcelain counterpart)
  3. Hydrophobic properties and anti-pollution design.
  4. High shock resistance
  5. Seismic and moist-discharge properties
  6. High resistance to torsion and flexure
  7. Vandal-proof design
  8. Safe coupling between flange and fiberglass rod (patent No 2173902, international application under the PCT, No PCT/RU02/00239)
  9. Application of organic-silicon rubbers produced by the world leading manufacturers with designed out-doors service life of at least 30 years
  10. No brittle failure and ten-fold mechanical FOS (factor of safety)
  11. Dielectric strength exceeds 40 kV/cm – as a result of a solid fiberglass rod application.
  12. Flanges are manufactured of substance not subject to corrosion (aluminum and zinc alloy).

Advantages of Polymer Insulator.

  1. Low costs (or no necessity at all) for Insulators cleaning.
  2. No need of zero value check.
  3. Light weight,  easy and economical to transportation and installation.
  4. Not brittle,  and reduce the purchasing quantities for spare parts.


National Switchgears is Manufacturer & Supplier Of Polymer insulator