墨西哥NOM标准下雷电防护系统设计的解决方案

针对墨西哥的NOM标准对于建构筑物雷电防护系统的设计规定与国标GB 50057和美标NFPA780差异较大的问题,基于墨西哥某集装箱码头工程,对墨标、国标、美标在建筑物防雷风险评估、年预计雷击次数、可承受雷击次数、外部防雷措施、接闪器、引下线及接地系统等方面进行分析比较,得出墨标在防雷风险评估及外部防雷措施上与国标及美标的主要区别点及雷电防护系统的设计步骤。结果表明,墨标以建筑物年预测雷击次数与规定的可承受雷击频率比较来确定是否需要设置外部防雷措施,国标的防雷分类法已经考虑了风险权重且易于执行,美标风险评估方法相对更复杂。

Solution scheme of lightning protection system design based on Mexican NOM standard

Aiming at the problem that it is quite different for the design of architecture lightning protection systems among Mexican NOM standard and Chinese standard GB 50057 and American standard NFPA780,we analyze the lightning risk assessment,annual threat of occurrence,the maximum annual threat which can be withstood by buildings,external lightning protection system,air terminal,down conductors,grounding system by comparing Mexican,Chinese and American standards based on a container terminal project in Mexico,and obtain the main differences among the three standards and the design steps of lightning protection system.The results show that it is required by NOM to decide whether need to set up an external lightning protection system based on comparing the annual threat of occurrence with the specified allowable frequency of threats,and the classification method provided by the Chinese standard is easy to implement with consideration of risk weight,and the lightning risk assessment required by American standard is more complex.