Low voltage line insulators are used for insulation and fixing of power line conductors with power frequency AC or DC voltage below 1KV. There are mainly needle type, screw type, spool type, tension and tram line insulator, etc. Butterfly and spool insulators can also be used for insulation and fixation of conductors on low-voltage line terminals, tension and corner rods. Tension insulator is used for insulation and connection of pole stay wire or tension conductor.
Insulators are widely used devices, and their connecting fittings are also required to be interchangeable. In addition, the technical standards of butterfly insulators also require various electrical, mechanical, physical and environmental condition change tests on insulators according to different models and service conditions, as well as environmental condition change tests, so as to test their performance and quality.