Purpose of Neutral section: Passing of pantograph under insulated overlap will cause short circuit between two phases, damaging OHE & pantograph. To avoid this bridging, a neutral section is inserted between them. Location: Located between two substations. Purpose of Section insulator: Section insulators are provided to insulate OHE of one elementary section from the OHE of another adjacent elementary section. Location: Located at cross over from one track to other, from main line to siding.