IEC 61558-2-16:2021

Overview

IEC 61558-2-16:2021 is an international standard published by the International Electrotechnical Commission (IEC) that specifies the safety requirements and testing procedures for switch mode power supply units (SMPS) and their associated transformers used in general applications. This second edition updates and replaces the earlier 2009 edition along with its 2013 amendment, introducing significant technical revisions to better align with the latest safety and performance norms within the electrotechnical industry.

The standard is intended to be utilized together with IEC 61558-1:2017, which provides general safety requirements for transformers and power supply units. IEC 61558-2-16:2021 focuses specifically on particular aspects of switch mode power supply units, including construction, insulation, electrical clearances, and protective measures. Its adoption ensures enhanced safety, reliability, and compliance for manufacturers and users within the global marketplace.

Key Topics

• Scope and Application
  Covers safety requirements and testing for SMPS units and transformers for SMPS used in general applications, addressing electrical, mechanical, and environmental safety.

• Technical Revisions
  Updates include alignment with IEC 61558-1:2017 structure and references, definitions of different voltage characteristics, and new alternative methods for calculating clearances.

• Safety Tests and Requirements
  Encompasses tests for protection against electric shock, insulation resistance, dielectric strength, partial discharge, overload and short-circuit protection, mechanical integrity, and ingress protection from dust and moisture.

• Electrical Clearances and Creepage Distances
  Provides detailed specifications for minimum distances required for safe insulation performance under various pollution degrees and frequency ranges, supporting effective design to withstand transient overvoltages and prevent electrical breakdown.

• Marking and Identification
  Defines symbols and marking protocols for output voltage, rated impedance, input voltage settings, and safety features, ensuring clarity and traceability.

• Annexes and Normative Additions
  Includes normative annexes detailing partial discharge testing, particular requirements for associated transformers with high internal frequencies, and informative guidance for clearances and creepage distance determination.

Applications

IEC 61558-2-16:2021 applies to a wide range of switch mode power supply units and their transformers, critical components in many electrical and electronic systems. Typical applications include:

• Consumer Electronics
  Ensuring safety and reliability in power supply units for devices such as computers, televisions, and audio equipment.

• Industrial Controls
  Power supplies for control panels, automation systems, and industrial machinery, where compliance with stringent safety requirements is mandatory.

• Medical Equipment
  Safety provisions help mitigate electric shock risks in power supplies for medical devices.

• Telecommunications Equipment
  Reliable SMPS units used in networking hardware and communication systems.

• General Electrical Devices
  Any equipment utilizing switch mode power supplies for voltage conversion and power management.

By adhering to this standard, manufacturers can guarantee product safety and performance, aiding global market access and regulatory compliance.

Related Standards

• IEC 61558-1:2017 – General safety requirements for transformers, reactors, and power supply units; IEC 61558-2-16 is a part 2 supplement to this normative baseline.

• IEC Guide 104 – Guidance on group safety publications, under which IEC 61558-2-16 holds status.

• IEC 60065 – Safety requirements for audio, video, and similar electronic apparatus, often related to power supply unit safety.

• ISO/IEC Directives – Provide the framework for the development of IEC standards, ensuring consistency and international relevance.

• Electropedia and IEC Vocabulary (IEV) – For terminological clarity and standardization in electrotechnology.

Integrating IEC 61558-2-16:2021 with these complementary standards supports comprehensive safety strategies for electrical and electronic equipment designers, manufacturers, and end users.

Keywords: IEC 61558-2-16, switch mode power supply units, SMPS safety standards, electrical clearances, creepage distances, transformer safety, IEC standards, power supply testing, electrical insulation, short-circuit protection, international electrotechnical commission, electrical safety compliance.