《民用建筑电气设计规范》第7.6.1条第2款规定“配电线路采用的上下级保护电器,其动作应具有选择性,各级之间应能协调配合。但对于非重要负荷的保护电器,可采用无选择性切断”。ZSI是实现上下级保护具有选择性的措施之一。ZSI是区域联锁选择性保护的英文缩写(Zone Selection Interlock),其核心有两点:当发生短路故障时,第 Section 2, Clause 2 of Clause 7.6.1 of “Code for Design of Civilian Buildings” stipulates that “the upper and lower protection electric appliances used in distribution lines shall be operated with selectivity and coordination among all levels, but for non-critical loads Protection of electrical appliances, can be selectively cut off ”. ZSI is one of the most selective measures for implementing superior and subordinate protection. The ZSI is the Zone Selection Interlock, which has two core points: when a short-circuit fault occurs, the