对中性导体截面积小于相导体时装设过电流保护的探讨

叶 充（广州市设计院集团有限公司，广州市 510620）

Discussion on Overcurrent Protection Device Installation When Cross‑sectional Area

of Neutral Conductor Is Less than That of Phase Conductor

YE Chong(Guangzhou Design Institute Group Co.,Ltd.,Guangzhou 510620，China)

Abstract： As for different understandings of overcurrent protection device installation when the cross‑sectional area of neutral conductor is less than that of phase conductor in Clause 7.4.5 of the Standard for Electrical Design of Civil Buildings(GB 51348 - 2019),the requirements of different standards for overcurrent protection of neutral conductor are compared,and analyzed from the perspective of short circuit protection and overload protection.

Key words：cable;neutral conductor;cross‑sectional area;overcurrent;short circuit protection;overload protection;harmonic current;unbalanced current

摘　要：结合GB 51348 - 2019《民用建筑电气设计标准》第7.4.5条规定（中性导体截面积小于相导体截面积时装设过电流保护）业内存在不同理解的情况，对比不同标准对中性导体过电流保护的要求，从短路保护及过负荷保护角度进行分析。

关键词：电缆；中性导体；截面积；过电流；短路保护；过负荷保护；谐波电流；不平衡电流

中图分类号：TU852      　　  　  文献标识码：A

doi：10.3969 / j. issn.1003 － 8493.2022.10.007