Identify factors which contribute to lightning-caused faults on overhead distribution lines. Suggest improvements to existing and new constructions. Present alternatives for reducing lightning-caused flashovers on overhead distribution lines. New IEEE Standard - Superseded. Superseded by IEEE 1410-2004. This guide will identify factors that contribute to lightning-caused faults on overhead distribution lines and suggest improvements to existing and new constructions. This guide is limited to the protection of distribution-line insulation for system voltages 69 kV and below. Equipment protection considerations are covered in IEEE Std C62.22-1991.