ČSN EN 50341-2-20 ed. 2

In Estonia the standard EN 50341-1 (Part 1) can only be applied using this NNA (EN 50341-2-20) containing National Normative Aspects for Estonia. This Part 2-20 applies to all new overhead electric lines with nominal system voltages exceeding AC 1 kV and also for low voltage (below 1 kV AC) overhead lines performed by aerial cables. The requirements of the structural design are applicable also for DC overhead lines, where the electrical requirements are given in the Project Specification. A "new overhead line" means a completely new line between two points, A and B. A new branch line of the existing power line should be considered as a new power line including the junction support. Specific requirements for junction support should be defined with the Project Specification.