Explanation : For low voltage lines (less than 11 kV), shackle insulators are used as strain insulators. However, for high voltage transmission lines, strings of cap-and-pin (suspension) insulators are used, attached to the crossarm in a horizontal direction. For voltages greater than 33 kV, it is a usual practice to use suspension type insulators, consisting of a number of glass or porcelain discs connected in series by metal links in the form of a string. ....Read more