Aes thumbnail

IEC 60947-6-1:2026: Transfer Switch (ATS) Standard

Automatically transfers the load to a generator (or alternative source) when the power grid fails. automatic transfer switch (ATS), It is a critical component of uninterrupted power infrastructure. Standards define the requirements for this equipment. IEC 60947-6-1’'is. Current edition. IEC 60947-6-1:2026 Updated with Edition 4.0, April 2026.

What is IEC 60947-6-1?

The full title is "“Low-voltage switching and control systems — Part 6-1: Multifunctional equipment — Transfer switching equipment”"is. Transfer switching equipment (TSE) and especially automatic transfer switching equipment (ATSE/ATS) It includes: rating values, usage categories, structural and performance requirements, and type tests.

Open passage, closed passage and bypass

The standard addresses different arrangements for how the transfer takes place:

  • Open transition: There is a brief interruption between the sources (first open, then close).
  • Closed transition: The resources remain parallel for a short time, uninterrupted transmission.
  • Bypass/Isolation (BTSE): power supply without disabling the main switch during maintenance.
  • ATS controller: Resource tracking and transfer logic (including independent controller)

Generator and fire pump applications.

Standard for generator power supply. voltage and frequency monitoring, It defines functions such as generator start-up contacts and transfer indicators. Also, normative Annex F, electrically driven fire pump It includes specific requirements for transfer equipment used with its remote control.

Importance in terms of periodic inspection

Topics evaluated by our authorized engineers during periodic inspections of generators and transfer panels include: ATS voltage/frequency sensing thresholds, transfer time, interlocking between sources, automatic generator on/off, main contact positions, and maintenance/bypass arrangement. Our related services and content:

Frequently Asked Questions

What is IEC 60947-6-1?

This is the IEC standard defining low-voltage transfer switching equipment (TSE) and automatic transfer switches (ATS/ATSE). The current edition is IEC 60947-6-1:2026 (Ed. 4.0, April 2026).

What is an ATS (automatic transfer switch)?

This is switching equipment that automatically transfers the load to an alternative source (usually a generator) when the mains power is interrupted, and transfers it back when the source is restored. ATSE, under IEC 60947-6-1, defines this function.

What is the difference between an open passage and a closed passage?

In an open-connection system, there is a brief interruption between the sources (open-close). In a closed-connection system, the sources remain in parallel for a very short time, and the transmission occurs without interruption.

Who performs the periodic inspection of the ATS/transfer switchboard?

Periodic inspections of generators and transfer panels are carried out by authorized engineers at AES Innovation in accordance with relevant standards and regulations; transfer time, detection thresholds, and interlocking functions are evaluated.

Other Topics