What does the IEC say about 10/350?

IEC - What is it?

The IEC stands for The International Electrotechnical Commission. It is a non-governmental international standards organization that prepares and publishes International Standards for all electrical, electronic and related technologies – collectively known as "electrotechnology". IEC standards cover a vast range of technologies from power generation, transmission and distribution to home appliances and office equipment, semiconductors, fibre optics, batteries, solar energy, nanotechnology and marine energy as well as many others. The IEC also manages three global conformity assessment systems that certify whether equipment, system or components conform to its International Standards.

Today, the IEC is the world's leading international organization in its field, and its standards are adopted as national standards by its members. The work is done by some 10,000 electrical and electronics experts from industry, government, academia, test labs and others with an interest in the subject.

What is TC 81?

Technical Committee TC 81 “Lightning Protection” was established in Stockholm in June 1980 with the scope to prepare international standards and guides for lightning protection of structures and buildings, as well of persons, installations, services and contents. The results of TC 81 are published in the international standard series IEC 62305.

Where does the IEC TC-81 say its 10/350 lightning model comes from?

"TC 81 decided as one of the first steps to define the lightning threat as a common basis to any protection measures. The lightning threat is mainly derived from the measurements of Berger performed at two 70 m towers on the Mountain San Salvatore in Switzerland. Up to now, the results published in CIGRE Electra in 1975 and 1980 represent the most complete data base of lightning currents and their relevant parameters." "PARAMETERS OF LIGHTNING CURRENT GIVEN IN IEC 62305 – BACKGROUND, EXPERIENCE AND OUTLOOK" by Heidler, F., Zischank, W., Flisowski, Z., Bouqueneau, Ch., and Mazetti, C. presented at 29th International Conference on Lightning Protection, Sweden, 2008.

In light of more recent research findings and flaws uncovered in some of Berger's data, has TC 81 shown any interest in re-visiting its lightning model or the 10/350 waveform?

Not yet. Their public statement, made 5 years ago in the above-referenced article said:

"Changes of lightning current parameters shall not be accepted in lightning protection standard until the results of the new CIGRE working group are available."