BS EN 50397-1:2020 pdf free.Covered conductors for overhead lines and the related accessories for rated voltages above 1 kV AC and not exceeding36 kV AC. BS EN 50397-1 This document contains the requirements for covered conductors with or without integrated longitudinal water tightness and/or semi-conductive conductor screen for applications in overhead lines with rated voltages U above 1 kV a.c....