Overhead electrical lines exceeding AC 1 kV. National Normative Aspects (NNA) for Great Britain and Northern Ireland (based on EN 50341-1:2012)|Alternating current, Alternating-current power transmission, Electric cables, Northern Ireland, Overhead line conductors, Loading, Scotland, Electric power distribution lines, Structural design, Electric power transmission lines, England, Power cables, Wales, Overhead contact lines, Electrical equipment, United Kingdom, High-voltage equipment, Electric power systems, Overhead power lines, Electric power transmission