IEC 60947-9-2:2021

Overview

IEC 60947-9-2:2021 is an international standard specifying requirements for active arc-fault mitigation systems with a focus on optical-based internal arc-detection and mitigation devices within low-voltage switchgear and controlgear assemblies. Published by the International Electrotechnical Commission (IEC), this standard addresses devices known as Internal Arc-fault Control Devices (IACDs). These systems are designed to detect internal arc-faults by processing at least the optical effects of the arc and to operate mitigation mechanisms to minimize damage and improve safety. The standard ensures consistent performance, safety, and reliability of optical arc-fault detection technologies in electrical installations.

Key Topics

• Scope and Classification: Defines IACD types including stand-alone, multifunction, and combined types. Specifies sensor types-optical only or optical combined with secondary sensors-to enhance detection capabilities.
• Detection and Mitigation Process: Covers optical detection methodologies to identify arc faults quickly. Emphasizes reducing arc-fault impact through fast operation of mitigation devices.
• Performance Requirements:
  • Maximum arc-fault detection and extinction times
  • Detection current thresholds and short-circuit current handling
  • Electromagnetic compatibility (EMC)
  • Temperature and environmental resilience
• Product Information & Markings: Specifies necessary product documentation, installation instructions, operational guidance, and maintenance protocols to ensure safe and effective use.
• Testing and Compliance:
  • Extensive testing procedures for light immunity, detection accuracy, dielectric properties, EMC, environmental conditions, and functional safety.
  • Routine and type testing to confirm standard compliance and system reliability in varied conditions.
• Optical Measurements and Calibration: Detailed annexes on photometric and radiometric measurement techniques critical for sensor calibration, sensitivity testing, and ambient light immunity assessments.

Applications

IEC 60947-9-2:2021 is critical for manufacturers, designers, and users of low-voltage switchgear and controlgear assemblies requiring enhanced protection against internal arc faults. Key application areas include:

• Electrical panels and distribution boards in commercial and industrial facilities
• Power distribution systems in manufacturing plants with high electrical loads
• Safety systems for critical infrastructure requiring rapid arc fault detection and mitigation
• Integration into smart electrical systems where active arc-fault monitoring is implemented
• Enhancing workplace electrical safety by minimizing arc-fault related hazards

This standard supports development and deployment of systems that improve electrical system resilience, protect personnel, and reduce equipment damage and downtime.

Related Standards

For comprehensive compliance and system integration, IEC 60947-9-2:2021 should be considered alongside related standards including:

• IEC 60947 Series - General standards for low-voltage switchgear and controlgear
• IEC 60364 - Electrical installations of buildings for safety requirements
• IEC 61439 - Low-voltage switchgear and controlgear assemblies
• IEEE 1584 - Guide for performing arc-flash hazard calculations (for context on arc hazard analysis)
• IEC 61000 Series - Electromagnetic compatibility (EMC) standards

These complementary standards ensure holistic safety, performance, and interoperability of low-voltage electrical systems with arc-fault detection technology compliant with IEC 60947-9-2.

By implementing the IEC 60947-9-2:2021 standard, organizations can achieve increased internal arc-fault safety, contribute to regulatory compliance, and advance innovations in electrical protection systems based on optical arc detection technology. This leads to safer, more reliable low-voltage switchgear installations worldwide.