IS EN 62305

The IS EN 62305 standard reflects increased scientific understanding of lightning and its effects over the last twenty years, and takes stock of the growing impact of technology and electronic systems on our daily activities. More complex and exacting than its predecessor, IS EN 62305 includes four distinct parts –┬áPart 1 General Principles, Part 2 Risk Management, Part 3 Physical Damage to Structures and Life Hazard, and Part 4 Electronic Systems Protection.

The IS EN 62305 standard for lightning protection was originally published in September 2006, to supercede the previous standard, BS 6651:1999

IS EN 62305-1 General principles – this provides the basic characteristics of an effective lightning protection system in accordance with the rest of the standards.

IS EN 62305-2 Risk management – details the wider considerations of lightning strikes such as danger to life, possible data loss, and cultural impacts if heritage buildings are damaged. Secondary economic implications of loss of services in the wake of lightning strikes are also analysed.

There are four types of loss to be considered in IS EN 62305-2:

R1 Loss of Human Life

R2 Loss of Services to the Public

R3 Loss of Cultural Heritage

R4 Loss of Economic Value

IS EN 62305-3 Physical damage to structures and life hazard – describes the basic categories of protection from lightning according to risk, and provides detailed guidance for an engineer designing a lightning protection system.

Class of Lightning Protection Faraday Cage Type Installation (Meters) Typical Distance of Down Conductors (Meters)
I 5 X 5 10
II 10 X 10 10
III 15 X 15 15
IV 20 X 20 20

IS EN 62305-4 Electrical and electronic systems within structures – provides updated information and guidance for the protection of the sensitive electronic equipment typical in modern buildings, including servers and wired networks. A zoning system is recommended to help protect such equipment from the primary and secondary effects of lightning strikes.