雷电防护.第2部分:风险管理

[中文适用范围]： IEC 62305的本部分适用于雷击对地造成的结构风险评估。其目的是提供评估此类风险的程序。一旦选择了风险的容忍上限，该程序就可以选择适当的保护措施，以将风险降低到或低于容忍限度。 [外文原描述]： IEC 62305-2:2010 is applicable to risk assessment for a structure due to 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 second edition cancels and replaces the first edition, published in 2006, and constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: 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. The value of tolerable risk of loss of economic value (RT = 10-3) is introduced, to be used when data for cost/benefit analysis are not available. 4) Extended damage to surroundings structures or to the environment is considered. 5) Improved equations 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. This bilingual version corresponds to the monolingual English version, published in 2010-12.