EN 50423-1:2005

Introduction
1 Scope
2 Definitions, list of symbols and references
   2.1 Definitions
   2.2 List of symbols
   2.3 References
3 Basis of design
   3.1 General
4 Actions on lines
   4.1 Introduction
   4.2 Actions, General approach
   4.3 Actions, Empirical approach
5 Electrical requirements
   5.0 General
   5.1 Voltage classification
   5.3 Insulation co-ordination
   5.4 Internal and external clearances
6 Earthing systems
   6.1 Purpose
   6.6 Site inspection and documentation of earthing systems
7 Supports
   7.1 Initial design considerations
   7.5 Timber poles
   7.6 Concrete poles
   7.7 Guyed structures
8 Foundations
   8.5 Geotechnical design
   8.6 Loading tests
9 Conductors and overhead earthwires (ground wires) with or
   without telecommunication circuits
   9.1 Introduction
   9.6 General requirements
10 Insulators
   10.1 Introduction
   10.2 Standard electrical requirements
   10.4 Pollution performance requirements
   10.5 Power arc requirements
   10.7 Mechanical requirements
   10.10 Characteristics and dimensions of insulators
   10.11 Type test requirements
   10.12 Sample test requirements
   10.13 Routine test requirements
   10.14 Summary of test requirements
   10.16 Selection, delivery and installation of insulators
11 Line equipment - Overhead line fittings
   11.2 Electrical requirements
   11.9 Characteristics and dimensions of fittings
Annex E (normative) Electrical requirements
Annex F (informative) Electrical requirements
Annex P (informative) Tests on overhead line insulators and
                      insulator sets in porcelain, and glass
                      insulating materials
Annex Q (informative) Insulators

This standard applies to bare and covered conductor overhead lines and overhead insulated cable systems with nominal voltage exceeding AC 1 kV up to and including AC 45 kV and with rated frequencies below 100 Hz. In general the requirements in EN 50341-1 apply. This standard specifies additional requirements and simplifications that apply only for this voltage range. In connection with EN 50341-1, this standard specifies the general requirements that shall be met for the design and construction of new overhead lines to ensure that the line is suitable for its purpose with regard to safety of persons, maintenance, operation and environmental considerations. This standard does not apply to: –overhead electric lines inside closed electrical areas as defined in HD 637 S1; –catenary systems of electrified railways unless explicitly required by another standard.