Sét hay tia sét là hiện tượng phóng điện trong khí quyển giữa các đám mây và đất hay giữa các đám mây mang các điện tích khác dấu đôi khi còn xuất hiện trong các trận phun trào núi lửa hay bão bụi (cát). | furse lr A Guide to BS EN 62305 2006 Protection Against Lightning Thomas Betts Foreword Furse is a world leader in the design manufacture and supply of earthing and lightning protection systems. Over 100 years of experience makes us acknowledged experts in the field. We provide technical support to our customers ranging from site visits system design advice detailed application drawings and training through to on-site supervision testing and commissioning. Quality approved to BS EN ISO 9001 2000 we are dedicated to providing cost-effective and highly efficient products and service. We have had a major involvement in the production of international standards on lightning protection over the past 15 years reflecting the UK s interpretation on lightning protection wherever possible. This publication offers an informative guide for designers engineers architects consultants and contractors and has been produced with the following aims. To briefly explain the theory and phenomenon of lightning. To precis and simplify where possible the British Standard Bs CENELEC EN 62305 Parts 1-4 Protection against lightning. All standards are open to individual interpretation. This handbook therefore reflects Furse s own views on good practice and it is not the intention that these views replace in any way the recommendations contained in the BS EN 62305 series but rather to be read in conjunction with the standard. We hope you find this handbook useful and should you require assistance or advice please do not hesitate to contact Furse at the Company s Head Office at the address shown on the reverse of this guide. furseC Contents Author s note and New standards on lightning protection 2 Theory of lightning 3 Characteristics of lightning Transient overvoltages surges Structure of BS EN 62305 10 BS EN 62305-1 General principles 11 Damage due to lightning Type of loss Need for lightning protection Protection measures Basic design criteria Lightning Protection Level LPL Lightning .
