National Normative Aspects (NNA) to EN 50341-1


09/2019- 10/2021  COMPLETED

Coordinator/ Submitting institution + WB6 Partners     

Tatjana Bojanic / Institute for Standardization, Serbia  


BiH: Institute for Standardization of Bosnia and Herzegovina BAS

Montenegro: Institute for Standardization of Montenegro ISME

Additional WB6 National Standardization Bodies (NSBs) if interested and technically capable for the task

Need for transnational action

The new CENELEC standard (EN 50341-1) for design and construction of overhead lines above 1 kV AC from December 2012 obliged member countries of CENELEC to prepare National Normative Aspects (NNA) reflecting national practices. In general, these national normative aspects include special national conditions (i.e. weather conditions), legal deviations and national complements.

Bosnia and Herzegovina, Montenegro and Serbia are small countries in the same geographical area, with similar climatological conditions and historically grown with the same regulations in this field. Therefore, the requirements for specific aspects to be defined in NNAs are the similar for the 3 countries. The formation of a regional working group addressing this issue will assure a harmonized approach for the closely connected economies and will create synergies by mutually learning from each other.


Standardisation institutes and technical experts develop specifications for a regionally harmonized draft NNA document for overhead electrical lines.

Project implementation

A working group for elaboration of NNA, consisting of expert from the 3 countries, has been formed at the end of 2018. On that occasion, six sub-groups for the preparation of certain aspects of the standard were established. The work of several sub-groups is currently in progress. Input by international experts at an initial kick-off workshop and continued support to the working groups shall support the formulation of the draft NNA and guidance document in line with best European practice. 

Expected impact

Besides the compliance with CENELEC requirements, transmission grid operators, manufacturers and contractors will benefit from having regionally agreed specifications for the construction and operation of overhead electrical lines. The activity contributes to the smooth operation of transnational transmission grids in Europe and therefore to a stability of the energy supply to European consumers.