(1) For low voltage lines (lessthan 11 kV), shackle insulatorsare used as strain insulators.However, for high voltage transmissionlines, strings of capand-pin (suspension) insulatorsare used, attached to thecrossarm in a horizontal direction.For voltages greater than33 kV, it is a usual practice touse suspension type insulators,consisting of a number of glassor porcelain discs connected inseries by metal links in the formof a string.