BS EN 62305-2:2012

BS EN 62305-2:2012 Protection against lightning. Risk management

BS EN 62305-2 outlines risk assessment for a structure or service from lightning flashes to earth.
Its purpose is to provide a procedure for the evaluation of such a risk. Once an upper tolerable limit for the risk has been selected, this procedure allows the selection of appropriate protection measures to be adopted to reduce the risk to or below the tolerable limit.

This document supersedes EN 62305-2:2006 + corrigendum November 2006.

BS EN 62305-2:2012 includes the following significant technical changes with respect to EN 62305-2:2006:

1) risk assessment for services connected to structures is excluded from the scope;

2) injuries of living beings caused by electric shock inside the structure are considered;

3) tolerable risk of loss of cultural heritage is lowered from 10-3 to 10-4;

4) extended damage to surroundings structures or to the environment is considered;

5) improved formulas are provided for evaluation of – collection areas relevant to flashes nearby a structure, – collection areas relevant to flashes to and nearby a line, – probabilities that a flash can cause damage, – loss factors even in structures with risk of explosion, – risk relevant to a zone of a structure, – cost of loss.

6) tables are provided to select the relative amount of loss in all cases;

7) impulse withstand voltage level of equipments was extended down to 1 kV.

 Contents of BS EN 62305-2:

1. Introduction
2. Scope
3. Normative references
4. Terms, definitions, symbols and abbreviations
5. Explanation of terms
6. Risk management
7. Assessment of risk components
8. Annex A (informative) Assessment of annual number N of dangerous events
9. Annex B (informative) Assessment of probability PX of damage
10. Annex C (informative) Assessment of amount of loss LX
11. Annex D (informative) Evaluation of costs of loss
12. Bibliography