MT 22 - TC 3/MT 22

IEC 60445:2021 applies to the identification and marking of terminals of electrical equipment such as resistors, fuses, relays, contactors, transformers, rotating machines and, wherever applicable, to combinations of such equipment (e.g. assemblies), and also applies to the identification of terminations of certain designated conductors. It also provides general rules for the use of certain colours or alphanumeric notations to identify conductors with the aim of avoiding ambiguity and ensuring safe operation. These conductor colours or alphanumeric notations are intended to be applied in cables or cores, busbars, electrical equipment and installations. This basic safety publication is primarily intended for use by technical committees in the preparation of standards in accordance with the principles laid down in IEC Guide 104 and ISO/IEC Guide 51. It has the status of a basic safety publication in accordance with IEC Guide 104.
IEC 60445:2021 cancels and replaces the sixth edition published in 2017. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) the definitions have been aligned with IEC 60050-195:2021 and IEC 60050-826;
b) the provisions for colour to be used for identification of certain designated conductors are made requirements and not only recommendations;
c) introduction of a new subclause on marking of protective terminals for multiple power supply inputs on equipment.