Lightning protection classes

Lightning protection class and classification

Before a lightning protection system is planned, the object to be protected must be assigned to one of four lightning protection classes. Efficiency in lightning protection class I is the highest at 98% and, in lightning protection class IV, the lowest at 81% (see table of hazard parameters). The cost and time involved in erecting a lightning protection system (e.g. necessary protective angle and spacings of grids and arresters) is more involved for lightning protection class I systems than for lightning protection class IV systems.

VdS Directive

The required lightning protection class is determined by assessing the damage risk in accordance with DIN EN 62305-2 (IEC 62305-2), unless specified in regulations. Directive VdS 2010 (risk-oriented lightning and surge protection), published by Gesamtverband der Deutschen Versicherungswirtschaft e . V. (GDV) offers an alternative method of determining the lightning protection class.

You can obtain further information at www.vds.de , via the OBO Customer Service +49 (0)2373 89-1500 or on our website.

Hazard parameters in dependence of lightning protection classes

Lightning protection class	Min. lightning current peak value	Max. lightning current peak value	Probability of air termination
I	3 kA	200 kA	98%
II	5 kA	150 kA	95%
III	10 kA	100 kA	88%
IV	16 kA	100 kA	81%

Lightning protection classes based on Directive VdS 2010

Application area	Lightning protection class
Computer centres, military applications, nuclear power stations	I
Ex zones in industry and the chemicals sector	II
Photovoltaic systems > 10 kW	III
Museums, schools, hotels with more than 60 beds	III
Hospitals, churches, storage facilities, meeting places accommodating more than 100 to 200 people	III
Administrative buildings, sales points, offices and bank buildings of over 2,000 m²	III
Residential buildings with more than 20 apartments, multi-storey buildings over 22 m high	III
Photovoltaics	III

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