爆炸性环境.第25部分:本安电气系统SUL 60079-251范围本标准包含本安电气系统的结构和评估的具体要求，防护类型“i”，拟全部或部分用于i类0,1或2区或20,21区，或国家电气规范®（NEC）、ANSI/NFPA 70®定义的22个危险（分类）位置。注1:本标准供系统设计师使用，其可能是制造商、专家顾问或终端成员- 用户的工作人员。本标准补充和修改了ANSI/ISA-60079-0和ANSI/ISA-61241-0以及本质安全标准ANSI/ISA-60079-11和ANSI/ISA-61241-11的一般要求。如果本标准的要求与所列标准的要求相冲突，则以本标准的要求为准。国家电气规范ANSI/NFPA 70规定了根据本标准设计的II组或III组系统的安装要求。

Explosive Atmospheres - Part 25: Intrinsically Safe Electrical SystemsUL 60079-251 ScopeThis standard contains the specific requirements for construction and assessment of intrinsically safe electrical systems, type of protection "i", intended for use, as a whole or in part, in Class I, Zone 0,1, or 2, or Zone 20, 21, or 22 hazardous (classified) locations as defined by the National Electrical Code ® (NEC), ANSI/NFPA 70®.Note 1: This standard is intended for use by the designer of the system who may be a manufacturer, a specialist consultant or a member of the end-user's staff.This standard supplements and modifies the general requirements of ANSI/ISA-60079-0 and ANSI/ISA-61241-0 and the intrinsic safety standard ANSI/ISA-60079-11 and ANSI/ISA-61241-11. Where a requirement of this standard conflicts with a requirement of these listed standards, the requirement of this standard takes precedence.The installation requirements of Group II or Group III systems designed in accordance with this standard are specified in the National Electrical Code ANSI/NFPA 70.