IEC 60938-2:2021

Overview

IEC 60938-2:2021 is an international standard published by the International Electrotechnical Commission (IEC) that defines specifications for fixed inductors specifically designed for electromagnetic interference (EMI) suppression. This part 2 of the IEC 60938 series focuses on power line chokes intended for connection to AC mains or other supplies with voltages not exceeding 1,000 V AC RMS or 1,500 V DC and nominal frequencies up to 400 Hz. The standard outlines mandatory safety tests, preferred ratings, characteristics, and performance requirements to ensure the reliable and safe operation of power line chokes in various electrical and electronic applications.

Key Topics

• Scope and Application
  IEC 60938-2 applies exclusively to fixed inductors used for EMI suppression on power lines where safety testing is required. It covers devices connected directly to mains supplies or used in circuits mandating specific safety tests, with scope extended to AC chokes up to 1,000 V and DC chokes up to 1,500 V.

• Preferred Ratings and Characteristics
  The standard prescribes preferred climatic categories, nominal inductance values, voltage ratings, temperature ratings, and rated currents to facilitate consistent product specifications.

• Safety and Performance Testing
  Comprehensive safety tests listed include voltage tests, insulation resistance, temperature rise, vibration and shock resistance, robustness of terminations, endurance tests, and impulse voltage testing. Optional tests address solderability, climatic sequences, flammability, and chemical resistance.

• Material and Design Requirements
  Material specifications harmonize with IEC 60939-3 and UL 60939-3 to ensure durability and reliability. Instructions include clear marking requirements, mounting dimensions, and design declarations to support uniform manufacturing and quality control.

• Test Scheduling and Sampling Plans
  Annexes detail unified test plans combining mandatory safety tests with optional performance tests, guiding manufacturers on proper validation and certification procedures.

Applications

IEC 60938-2:2021 power line chokes are essential components in mitigating electromagnetic interference in electrical and electronic systems connected to the power mains. Common practical uses include:

• Power Supply Systems
  Suppression of electrical noise in power converters, adapters, and industrial power supplies enhancing the stability and EMI compliance of devices.

• Electrical Equipment and Appliances
  Integration in household and industrial equipment to reduce conducted interference and improve overall electromagnetic compatibility.

• Renewable Energy and Grid Infrastructure
  EMI suppression in solar inverters, wind turbines, and smart grid devices to maintain power quality and protect sensitive electronics.

• Telecommunications and Data Centers
  Ensuring interference-free operation of communication equipment and servers by limiting noise coupling through power lines.

Using power line chokes compliant with IEC 60938-2 ensures adherence to stringent international safety and performance standards, facilitating global market access and reducing electromagnetic disturbances.

Related Standards

To support full compliance and integration of EMI suppression devices, IEC 60938-2 should be considered alongside other relevant standards:

• IEC 60938-1 – General requirements for fixed inductors used in EMI suppression, providing overarching principles referenced within part 2.

• IEC 60939-3 / UL 60939-3 – Specifications on materials used for inductors, harmonizing design and safety aspects for components.

• IEC 61000 Series – Electromagnetic compatibility (EMC) standards addressing immunity and emission requirements in electrical and electronic equipment.

• IEC 61189 Series – Testing methods for electronic components mounted on Printed Circuit Boards (PCBs), useful in assessing termination robustness for surface-mounted power line chokes.

Implementing IEC 60938-2 within the framework of these associated standards ensures engineered EMI suppression solutions meet universal safety, performance, and reliability criteria.

Keywords: IEC 60938-2, power line chokes, fixed inductors, electromagnetic interference suppression, EMI chokes, IEC standards, safety tests, AC mains inductors, DC chokes, inductance specifications, electromagnetic compatibility, inductor ratings, performance testing