Overview
IEC 60940:2026 is the authoritative international standard specifying general rules and safety requirements for the application of capacitors, resistors, inductors, and complete filter units designed for electromagnetic interference (EMI) suppression. Published by the International Electrotechnical Commission (IEC), this standard covers components connected to AC mains or other supply systems (AC or DC) with a nominal voltage not exceeding 1,000 V AC (up to 400 Hz) or 1,500 V DC.
IEC 60940 provides a comprehensive framework enabling product safety standard drafters, equipment designers, manufacturers, service providers, policy makers, and regulators to address both intended use and reasonably foreseeable misuse in products and systems. It promotes risk management strategies for achieving tolerable risk levels related to EMI suppression components.
This third edition introduces notable updates, including converting guidance into general rules and safety requirements, and adding extensive new content addressing safety aspects, component selection, distances for insulation, flammability, and best practices for using X and Y capacitors.
Key Topics
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Scope of Application
- EMI suppression using capacitors, resistors, inductors, and filter units for electrical and electronic systems
- Applicable to AC mains and DC supply systems up to defined voltage and frequency limits
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Component Classification
- Capacitors: Two-terminal/single, multi-section, lead-through, and combinations with resistors
- Resistors: Fixed and variable types for voltage reduction and current limitation
- Inductors: Various core types, including common-mode chokes and ferrite beads for filtering differential and common-mode interference
- Filters: Passive low-pass filter combinations, with or without protective housings
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EMI and Safety Requirements
- Strategies for suppressing conducted and radiated EMI/RFI
- Limitations on earth leakage current and electrical hazards stemming from component failures (e.g., shock, heat, fire)
- Rules for series components, clearance, and creepage distances for insulation safety
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Selection and Risk Assessment
- Procedures for selecting appropriate ratings for EMI suppression components based on environmental and operational conditions
- Consideration of steady-state and transient voltages, including temporary and recurring peak voltages
- Importance of information sharing by manufacturers regarding failure modes and probabilities for risk analysis
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Flammability and Use of X and Y Capacitors
- Guidance on passive and active flammability aspects
- Specific guidelines for X and Y capacitor applications in AC mains up to 400 Hz, including considerations for voltage derating
Applications
IEC 60940:2026 is integral to:
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Product Design and Certification
- Assisting manufacturers and designers in selecting and applying safe, compliant EMI suppression components in power supplies, consumer electronics, industrial equipment, and electrical appliances
- Supporting compliance with EMC and product safety standards (e.g., CISPR, IEC 60384-14) to ensure safe operation and market approval
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Development of Product Standards
- Guiding technical committees and policymakers in drafting or revising product and system-level safety standards for electrical and electronic products
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Regulatory and Policy Implementation
- Providing a foundation for regulatory requirements in the suppression of electromagnetic interference in equipment connected to public power supply networks
Related Standards
For effective application of IEC 60940:2026, the following related international standards should be considered:
- IEC 60384-14: Specifications for capacitors used in EMI suppression and AC mains applications
- IEC 60939-3: Safety tests for passive filter units for EMI suppression
- IEC 60664-1: Insulation coordination within low-voltage supply systems
- IEC 61140: Common requirements for protection against electric shock
- CISPR 17: Methods for measuring the suppression characteristics of passive EMC filtering devices
- IEC Guide 104 & Guide 116: Guidance for safety publications and risk assessment in low-voltage equipment
- ISO/IEC Guide 51: Guidelines for the inclusion of safety aspects in standards
By adhering to IEC 60940:2026, organizations can ensure robust electromagnetic compatibility and electrical safety, reducing risks in design, manufacturing, and application of EMI suppression components across diverse sectors.