Distribution arresters have been used on power systems for over a century during which time there has been a complete changeover in housings from ceramic to polymeric. Porcelain arresters often had issues with sealing and water ingress that sometimes resulted in ‘clear sky, sunny day’ failures.

Before installation on overhead lines, quality of polymeric insulators must be approved through full design and type testing. Subsequently, manufacturers are responsible for performing sample and routine tests. Moreover, in many cases, users also demand special acceptance tests.

Insulators are widely used in overhead transmission lines to provide mechanical support and electrical protection, as well as in distribution lines and substations.

The butterfly insulators and pin insulators in ceramic insulator products are mainly used for high and low voltage transmission lines, and suspension insulators are used for high voltage transmission lines.

A surge arrester is a device to protect electrical equipment from over-voltage transients caused by external (lightning) or internal (switching) events.

Application of silicone composite insulators has increased significantly over the past 30 years. One of the key factors behind continued growth will be the confidence shown in them by power utilities.