Lightning Protection Upgrades
Some structures may have lightning protection systems that were designed to BS6651 or even earlier CP326 :1965, these were based on the knowledge of lightning at that time. Since then we have moved on and with increased understanding systems are now designed to BSEN 62305
Older lightning protection systems simply would not offer the level of protection required to protect the building and occupants. Upgraded systems form a “Faraday Cage”. This is formed by grids of lightning conductors, essential making a mesh over the structure. The size of the grid is dependent on a Risk Assessment (see below). This mesh should be designed to conduct a strike to ground equally around the building, thus reducing the current in each path to earth. Care should be taken not to introduce any paths to earth within the protective Faraday Cage. Western Lightning can provide you with a lightning protection design that meets all requirements of BS EN 62305.
Risk Assessments
Lightning flashes to earth may be hazardous to structures and to services. The hazard to a structure can result in:
* Damage to the structure and to its contents,
* Failure of electrical and electronic systems,
* Injury to living beings in or close to the structure.
Each type of damage, alone or in combination with others, may produce a different consequential loss in the object to be protected.
The type of loss that may appear depends on the characteristics of the object itself and its content. The following types of loss are taken into account:
* loss of human life;
* loss of service to the public;
* loss of cultural heritage;
* loss of economic value (structure and its content, service and loss of activity).
In order reduce the loss due to lightning, protection measures may be required. Whether they are Needed or not, and the extent of protection necessary, should be determined by a risk assessment.
Lightning protection measures in accordance with the current regulation may reduce the damage probabilities or the amount of consequential loss. The decision to provide lightning protection may be taken regardless of the outcome of any risk assessment where there is a desire that there be no avoidable risk.
