What are the basic groups of insulators?
Pintype insulators are grouped by a number of different characteristics: • Material that the insulator is made from: • Glass • Porcelain • Nonglass-Nonporcelain (such as rubber, wood, or plastic) • Place of origin: • North America (including Canada and Mexico) • Foreign • Number of parts: • “Unipart” – any one-piece insulator • “Multipart” – any insulator of two or more separately molded parts, either cemented together during or after manufacture, or used together on the line • Threading characteristics: • Threaded – an insulator with internal screw threads which correspond to matching threads on a pin • Threadless – an insulator without threads and having a smooth pinhole There are also non-pintype insulators, which include spools, dead end insulators, and wire strain insulators.
