IEC 62873-1:2017+A1:2020. The IEC 62873 series covers available common standards intended to be used in conjunction with or for the preparation of RCD (residual current device) standards. This part of IEC 62873 defines the methodology and processes used when producing standards based on a new approach (hereafter referred to as blocks and modules) aiming at harmonizing a family of standards, thus avoiding mistakes, inconsistencies or discrepancies within this family of standards. The family of standards considered in this document consists of standards for RCCBs (Residual Current Circuit-Breakers without overcurrent protection), RCBOs (Residual Current Circuit-Breakers with overcurrent Protection), and general safety requirements for residual current operated protective devices (namely IEC 61008-1, IEC 61009-1 and IEC TR 60755). This consolidated version consists of the first edition (2017) and its amendment 1 (2020). Therefore, no need to order amendment in addition to this publication.