IEC 61000-3-12:20 11涉及注入公共供应系统的谐波电流的限制。本国际标准中给出的限值适用于额定输入电流超过16 A且每相不超过75 A、旨在连接到公共低压交流电的电气和电子设备。以下类型的配电系统: -额定电压高达240 V，单相，两线或三线； -标称电压高达690 V，三相，三或四线； -标称频率50Hz或60Hz。不包括其他分配系统。本版中给出的限制适用于连接到230/400 V、50 Hz系统的设备。本标准适用于打算连接到低压系统的设备，该系统与低压公共电源接口电压等级。它不适用于仅连接到仅在中压或高压水平与公共电源接口的私人低压系统的设备。本标准定义: a)设备的要求和排放限值； b)型式试验和模拟的方法。根据本国际标准进行的试验是成套设备的型式试验。也可以通过经验证的模拟来确定是否符合本标准。第二版取消并取代了2004年出版的第一版，构成了技术修订。与上一版相比，重大技术变化如下: -用参考电流Iref替换参考基波电流I1，用于计算发射极限； -新增现行排放限值表（表5）；-新增加的附件（附件A），以界定某些类型设备的测试条件； -删除以前的附件B（近似插值公式）和D（关于PWHD系数的信息）。

IEC 61000-3-12:2011 deals with the limitation of harmonic currents injected into the public supply system. The limits given in this International Standard are applicable to electrical and electronic equipment with a rated input current exceeding 16 A and up to and including 75 A per phase, intended to be connected to public low-voltage a.c. distribution systems of the following types:
- nominal voltage up to 240 V, single-phase, two or three wires;
- nominal voltage up to 690 V, three-phase, three or four wires;
- nominal frequency 50 Hz or 60 Hz. Other distribution systems are excluded. The limits given in this edition apply to equipment when connected to 230/400 V, 50 Hz systems. This standard applies to equipment intended to be connected to low-voltage systems interfacing with the public supply at the low-voltage level. It does not apply to equipment intended to be connected only to private low-voltage systems interfacing with the public supply only at the medium- or high-voltage level. This standard defines:
a) requirements and emission limits for equipment;
b) methods for type tests and simulations. Tests according to this International Standard are type tests of complete pieces of equipment. Conformity with this standard can also be determined by validated simulations. This second edition cancels and replaces the first edition published in 2004 and constitutes a technical revision. The significant technical changes with respect to the previous edition are:
- the replacement of the reference fundamental current I₁ by the reference current I_ref for the calculation of emission limits;
- a new added table of current emission limits (Table 5);
- a new added annex (Annex A) to define test conditions for some types of equipment;
- Deletion of the former Annexes B (Approximate interpolation formulas) and D (Information on the PWHD factor).