IEC 61326-3-2:2017

Overview

IEC 61326-3-2:2017 is an international standard published by the International Electrotechnical Commission (IEC) focusing on electromagnetic compatibility (EMC) immunity requirements for electrical equipment used in measurement, control, and laboratory applications. This part of the IEC 61326 series establishes immunity requirements for safety-related systems and equipment designed to perform safety-critical functions in industrial environments with a specified electromagnetic environment. The standard addresses functional safety as defined by IEC 61508 for equipment and systems with Safety Integrity Levels (SIL) 1-3.

This second edition (2017) supersedes the 2008 version with significant technical updates, including revised performance criteria, expanded frequency ranges for testing, and improved test setups. Compliance ensures reliable operation of critical equipment under electromagnetic disturbances, contributing to industrial safety and regulatory conformity.

Key Topics

• Scope and Applicability: IEC 61326-3-2:2017 applies to equipment within the scope of IEC 61326-1, specifically targeting industrial application systems and equipment intended to perform defined safety functions in specified electromagnetic environments. Systems considered as “proven-in-use” per IEC 61508 and certain alarm systems are excluded.

• Functional Safety Focus: The standard ensures that equipment involved in safety-related functions maintains its intended operation under electromagnetic disturbances, supporting risk reduction goals as defined by Functional Safety standards.

• Electromagnetic Environment: It addresses unique industrial characteristics, such as:

  • Restricted access to industrial areas
  • Limited use of mobile transmitters
  • Use of dedicated and separated cables for power, control, and communication
  • Metal construction of facilities
  • Implementation of overvoltage and lightning protection
  • Regular maintenance and competent personnel

• Technical Revisions:

  • Extended test frequencies up to 6 GHz (radio-frequency immunity per IEC 61000-4-3)
  • Introduction of performance criterion DS, superseding FS, aligned with IEC 61000-6-7
  • Immunity testing for equipment with current consumption above 16 A (per IEC 61000-4-34)
  • Use of IEC 61000-4-16 tests in the 10 kHz to 150 kHz range
  • Enhanced guidelines and test configurations for clearer, more robust verification

• Performance Criteria: Specified test plans and performance criteria ensure equipment reliability and predictable behavior in the presence of electromagnetic interference, essential for equipment impacting safety functions.

Applications

IEC 61326-3-2:2017 is practically valuable in several domains, including:

• Industrial Process and Manufacturing: Ensuring uninterrupted function of measurement, control, and automation equipment critical for plant safety in sectors like chemical, petrochemical, and pharmaceutical industries.
• Functional Safety Systems: Supporting risk assessment and mitigation efforts for systems with stringent SIL requirements, as specified in IEC 61508.
• Factory and Laboratory Environments: Assuring that laboratory instruments and industrial control equipment maintain operational safety during EMC disruptions.
• System Integration and Compliance Testing: Providing clear test methodologies and performance criteria for manufacturers and system integrators working on safety-related automation and control applications.

By complying with IEC 61326-3-2:2017, stakeholders ensure that safety-related equipment will perform as intended, helping meet regulatory requirements and protecting personnel and assets.

Related Standards

For comprehensive EMC and functional safety compliance in industrial environments, the following international standards are closely related:

• IEC 61326-1: General EMC requirements for measurement, control, and laboratory equipment
• IEC 61000-4-3, -4-16, -4-34: EMC immunity test methods and requirements
• IEC 61508: Functional safety of electrical/electronic/programmable electronic safety-related systems (defining SILs and safety functions)
• IEC 61000-6-7: Generic functional safety EMC standard for industrial environments
• IEC 61326-3-1: Immunity requirements for safety-related systems-general industrial applications
• IEC 61511: Functional safety for process industry sector

Understanding and leveraging these standards alongside IEC 61326-3-2:2017 strengthens EMC and functional safety strategies, ensuring resilient operation of safety-critical electrical equipment in industrial settings.