IEC 61558-2-1:2007

Overview

IEC 61558-2-1:2007 is an international standard published by the International Electrotechnical Commission (IEC) that focuses on the safety of separating transformers and power supplies incorporating such transformers for general applications. This part of the IEC 61558 series specifically addresses the particular requirements and testing procedures essential to ensuring the electrical, thermal, and mechanical safety of these devices.

This second edition replaces the first edition from 1997 and reflects important technical revisions, including alignment with Part 1 Edition 2 of IEC 61558 and the expanded inclusion of power supplies within its scope. As a group safety publication under IEC Guide 104, it provides foundational and structured safety requirements applicable worldwide, facilitating safer design, manufacturing, and use of separating transformers in various electrical products.

Keywords: IEC 61558-2-1, power transformer safety, separating transformers, power supply safety, electrical safety standards, IEC standards, transformer testing

Key Topics

• Scope and Application

  • Safety requirements for general-purpose separating transformers with separate windings
  • Inclusion of power supplies incorporating separating transformers
  • Covers electrical, thermal, and mechanical safety aspects

• Testing Requirements

  • Procedures ensuring compliance with insulation resistance, dielectric strength, and leakage current limits
  • Protection against electric shock
  • Verification of heat resistance and temperature rise limits
  • Mechanical strength and durability assessments
  • Testing for short-circuit and overload protection
  • Verification of marking, labeling, and safety instructions

• Design and Construction Factors

  • Standards for components, internal wiring, and terminals
  • Requirements for protective earthing and clearances
  • Resistance to ingress of dust, moisture, and corrosion
  • Mechanical stability and robust construction criteria

• Classification and Ratings

  • Definitions of transformer classes and rated values
  • Guidelines on voltage, current, and power ratings for separating transformers

Applications

IEC 61558-2-1:2007 is essential for manufacturers, testing laboratories, and regulatory bodies involved with:

• General-purpose separating transformers, widely used in industrial, commercial, and residential electrical systems.
• Power supplies incorporating separating transformers, ensuring safety in devices like medical equipment, industrial controls, and consumer electronics.
• Compliance with international safety standards for transformers used in power distribution, signal isolation, and noise reduction.
• Designing products for markets requiring IEC conformity to meet electrical safety regulations.

This standard supports safer electrical infrastructure by minimizing hazards such as electric shock, overheating, and mechanical failure, essential for protecting users, equipment, and property.

Related Standards

• IEC 61558-1: General safety requirements and tests for power transformers and power supplies
• IEC Guide 104: Development of safety publications and group safety publications
• IEC 60034 series: Rotating electrical machines (for related electrical safety requirements)
• IEC 60601 series: Medical electrical equipment safety, often requiring compliance with IEC 61558 series for transformers in medical applications
• IEC 60335 series: Safety of electrical appliances involving transformers

These related IEC standards complement IEC 61558-2-1 to provide comprehensive safety frameworks for electrical transformers and associated power products across multiple industries.

By adhering to IEC 61558-2-1:2007, manufacturers and users can ensure reliable, safe operation of separating transformers and power supplies, supporting international trade and regulatory compliance while protecting end-users from electrical hazards.