BSI BS EN IEC 60947-6-1:2026

IEC 60947-6-1:2026 RLV is available, which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.

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 different types of equipment are given in the following annexes:

• Annex C: Bypass/isolation transfer switch equipment
• Annex D: ATSE having closed transition capability
• Annex E: Stand-alone ATS controllers
• Annex F: TSE for electric driven fire pump controllers

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