IEC 61821:2011适用于AGL恒流串联电路的维护。本国际标准: -涵盖安装在机场和直升机场的AGL的恒流串联电路； -专注于提供AGL恒流串联电路维护的安全要求。认识到存在不同设计特性和参数的AGL恒流串联电路； -主要关注人员安全，具体规定AGL恒流串联电路的维护规则和基本原则； -不适用于直接由市电恒压源供电的AGL初级串联电路； -不打算用于公共街道照明、道路照明或任何其他需要使用恒流串联电路的安装。第二版取消并取代了2002年出版的第一版。这是一次技术修订。与上一版相比，此版本包括以下重大技术变更: a)增加对规范性参考文献的引用； b)在第5、6及7条中加入注释； c）修改7.2.2 e）项中的前期工作程序。

IEC 61821:2011 applies to the maintenance of AGL constant current series circuits. This International Standard:
- covers constant current series circuits for AGL installed at aerodromes and heliports;
- concentrates on providing the safety requirements for the maintenance of an AGL constant current series circuit. It is recognized that AGL constant current series circuits of different design characteristics and parameters are in existence;
- is mainly concerned with safety to persons by specifying the rules and fundamental principles for the maintenance of AGL constant current series circuits;
- is not intended to apply to AGL primary series circuits supplied directly from a mains constant voltage source;
- is not intended to be used for public street lighting, roadway lighting or any other installation requiring the use of constant current series circuits.
This second edition cancels and replaces the first edition published in 2002. It is a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) addition of references to normative references;
b) addition of notes in Clauses 5, 6 and 7;
c) modification of pre-work procedures in item e) of 7.2.2.