The UK committee advises users that the BS EN IEC 62305 third edition series should be implemented in full as it would not be safe to implement parts 1, 3 and 4 of the third edition without having done a risk assessment in accordance with BS EN IEC 62305-2:2024.
What is BS EN IEC 62305-3:2024 - Protection against lightning physical damage to structures and life hazard about?
The third in a four-part international series on lightning protection measures, BS EN IEC 62305-3:2024 deals with how to protect buildings and human beings from lightning.
The other standards in the series are:
- BS EN IEC 62305-1 General principles
- BS EN IEC 62305-2 Risk management
- BS EN IEC 62305-4 Electrical and electronic systems within structures
Who is BS EN IEC 62305-3:2024 - Protection against lightning physical damage to structures and life hazard for?
BS EN IEC 62305-3:2024 is essential for anyone directly or indirectly involved in lightning protection, most likely in the built environment, health and safety, risk management, and electrical engineering sectors.
Specific users will include:
- architects involved in the design and construction of large and critical buildings, including the retrofit installation of equipment in existing buildings having lightning protection;
- surveyors involved in design and construction of large and critical buildings including the retrofit installation of equipment in existing buildings having lightning protection;
- engineers involved in the design and manufacture of lightning protection components;
- builders involved in construction of large and critical buildings;
- facility managers involved in maintenance of large and critical buildings;
- electrical engineers in specialist earthing companies;
- high voltage engineers; and
- consultants and specification engineers.
What does BS EN IEC 62305-3:2024 - Protection against lightning physical damage to structures and life hazard cover?
BS EN IEC 62305-3:2024 sets out all the requirements needed to protect buildings and structures against physical damage by implementing a lightning protection system (LPS). It also looks at how to protect human beings against injury if they are close to an LPS.
Why should you use the standards in the BS EN IEC 62305 series?
Efficacy: lightning discharges are an unpreventable and hazardous weather phenomenon. Protection measures are essential and the measures in the BS EN IEC 62305 series of standards are proven to be effective at reducing risk.
Assurance: the BS EN IEC 62305 series of standards give assurance that a building design provides adequate protection against lightning. It gives assurance that retrofitted equipment is sufficiently separated from lighting conductors and lightning bonded equipment, or if this isn’t possible, that appropriate bonding is performed. And it gives assurance that an appropriate maintenance cycle is adopted.
Knowledge: the BS EN IEC 62305 series of standards provide a robust, up-to-date understanding of the specific requirements of lightning earthing and, especially in Part 1, the electrical characteristics of lightning positive and negative strokes.
Empowerment: the BS EN IEC 62305 series of standards give users sufficient knowledge of lightning protection to understand the outcome of a lightning risk assessment and write specifications for installation and maintenance contracts.
What has changed?
BS EN IEC 62305-3:2024 includes the following significant technical changes:
- minimum thicknesses of metal sheets or metal pipes are given in Table 4 for air-termination systems where it is necessary to prevent hot-spot problems. Maximum temperature rises ΔT (K) and time duration t50 (s) for different thicknesses and long strokes are also given;
- cross reference to the IEC 62561 series is made for the use of reliable, stable, safe and appropriate LPS components;
- the application of two methods – general and simplified – for separation distance calculation is clarified;
- some changes to the requirements for continuity of steel reinforcement are made;
- Annex C is revised to address comments from IEC subcommittee 31J;
- revision of positioning of air-termination conductors according to the three accepted methods and a more precise description of the methods for positioning of the air-termination systems, according to the complexity of structures to be protected, are made. The main text has been simplified, Annex A has been deleted and all detailed information has been moved to Annex D;
- information on the protection of green roofs is introduced in Annex D; and
- information on the protection of protruding parts on facades of tall buildings is introduced in Annex D.
