Wednesday 10 April 2013

The dangers of designing an incorrect level of protection.

Since September 2008 the lightning protection industry has been working to BSEN62305. The main difference between this and the previous British Standard (BS6651) was the introduction of a complex risk analysis calculation to establish which of four levels of protection should be applied to a particular structure.  Levels, or Classes of protection, range from 1 to 4 and are dependent on a number of factors, the major contributor being the actual physical size of the structure to be protected. Level 1 is the most stringent through to level  4 being the least  in terms of the amount of protection actually required. This inevitably gives rise to price differences between the various levels at quotation stage.

All Churchill’s lightning protection designers hold an ATLAS (The Association of Technical Lightning and Access Specialists) certificate of accreditation to demonstrate design competence, and are trained in the use of industry specific software to carry out these risk analysis and the subsequent design.

Until our sector is fully up to speed with how to complete the new risk assessments the very real risk is that companies may either through lack of training, or perhaps even in an attempt to achieve commercial gain choose to endorse Lightning Protection designs and installations which are non-compliant with BSEN62305 by using the incorrect level of protection.

For example, a group of structures physically linked together have to be classed as one complete structure and would therefore warrant a greater level of protection (possibly level 1 or 2) at a greater cost implication than if they were completely isolated, where they may only warrant a level 4 for instance.

“Loss of human life” is the primary reason for providing protection in the first instance. The final level of protection based on the information available to the designer is therefore of critical importance for obvious reasons. The responsibility for which, as well as the financial risk to rectify any non- compliance, may well fall on the original contractor or indeed the client.

Something to be avoided at all costs.