EN IEC 60947-6-1:2026

IEC 60947-6-1:2026 applies to transfer switching equipment (TSE), to be used in power systems for ensuring the continuity of the supply and allowing the energy management of the installation, by transferring a load between power supply sources, the rated voltage of which does not exceed 1 000 V AC or 1 500 V DC. Specific requirements for bypass/isolation transfer switch equipment are given in Annex C, ATSE having closed transition capability are given in Annex D, stand-alone ATS controllers are given in Annex E, and TSE for electric driven fire pump controllers are given in Annex F.It covers:- manually operated transfer switching equipment (MTSE);- remotely operated transfer switching equipment (RTSE);- automatic transfer switching equipment (ATSE), including the controller;- stand-alone ATS controllers;- bypass/isolation transfer switch equipment (BTSE);- ATSE having closed transition capability;- fire pump TSE.It does not cover:- TSE configurations that are not fully manufacturer type tested or marked according to this document as a complete transfer switch;- auxiliary contacts (for guidance, see IEC 60947-5-1);- transfer switches used in explosive atmospheres (for guidance, see IEC 60079 (all parts));- embedded software design (for guidance, see IEC TR 63201);- cybersecurity aspects (for guidance, see IEC 63208);- TSE rated for direct-on-line starting asynchronous motor of design NE and HE, according to IEC 60034-12. (for guidance, see AC-3e utilisation category according to IEC 60947 4 1);- other types of TSE under consideration including overlapping neutral TSE, multi-source TSE (i.e. TSE with more than two sources of supply), TSE with load-shedding functions, bus-tie TSE, and hybrid TSE;- static transfer switches covered by IEC 62310 series.This fourth edition cancels and replaces the third edition published in 2021. This edition constitutes a technical revision.This edition includes the following significant technical changes with respect to the previous edition:- clarification of scope;- clarification of terms and definitions;- Annex C for Bypass/Isolation Transfer Switch Equipment;- Annex D for ATSE having closed transition capability;- Annex E for Stand-alone ATS controller;- Annex F for TSE used with electric driven fire pump control equipment.