IEC 60310:2026

Overview

IEC 60310:2026 is the internationally recognized standard developed by the International Electrotechnical Commission (IEC) for railway applications, specifically governing the requirements for transformers and inductors onboard rolling stock. This standard outlines terminology, classification, service conditions, performance characteristics, and test methods for both traction and auxiliary transformers and inductors used within train vehicles. Both dry and liquid-immersed designs are covered, ensuring uniformity and safety across a diverse range of rolling stock electrical equipment.

The fifth edition introduces significant technical updates, including revised test methods and new guidance for both transformers and inductors. By adhering to IEC 60310:2026, railway manufacturers, integrators, and operators promote interoperability, reliability, and safety of electrical systems on board vehicles.

Key Topics

• Scope and Definitions: IEC 60310:2026 details vocabulary, classifications, and service conditions for power transformers and inductors installed in rolling stock. It addresses mainline, urban, and regional trains, as well as specialized vehicles with three-phase AC or multi-phase auxiliary circuits.

• Exclusions: The standard does not apply to instrument transformers, smaller transformers (below 1 kVA for single-phase or 5 kVA for poly-phase), and inductors below the same capacity. Accessories mounted on transformers/inductors such as tap changers and fans are covered by other standards.

• Technical Revisions in 2026 Edition:

  • Addition of typical circuit diagrams for transformers and inductors
  • Introduction of letter symbols for various cooling methods
  • Updated dielectric test tables
  • Restructuring of test methodology subclauses
  • Separation of temperature test requirements for dry-type transformers and inductors
  • Revised shock and vibration test criteria, harmonized with IEC 61373

• Service and Performance Requirements:

  • Guidelines for rated current, voltage, and load profile specification
  • Cooling method identification and associated symbol arrangement
  • Temperature limits for components, with separate attention to solid and liquid insulation
  • Requirements for mechanical design and fire protection measures
  • Rating plate data for clear identification

• Test Procedures:

  • Type tests, routine tests, and investigative testing procedures
  • Detailed tolerances, checklists, and measurement methods (resistance, inductance, loss, insulation, noise, etc.)
  • Temperature-rise, dielectric, partial discharge, and withstand tests for validating equipment durability and electrical safety

Applications

• Traction Transformers: Essential for supplying power to traction circuits in all types of rail vehicles, including mainline locomotives and EMUs.

• Auxiliary Transformers: Used for powering onboard electrical systems separate from traction, such as lighting, HVAC, and passenger amenities.

• Power Inductors: Installed in both traction and auxiliary circuits to manage load fluctuations, filter harmonics, and improve power quality.

• Three-Phase and Polyphase Systems: The standard is applicable to vehicles powered by three-phase AC as well as those with complex auxiliary circuits, following mutual agreement between supplier and customer.

• Safety and Reliability: Ensures that all transformers and inductors onboard comply with rigorous performance, safety, and durability benchmarks, supporting dependable train operation.

Related Standards

For comprehensive railway electrical system compliance, consult the following related IEC and ISO standards:

• IEC 60076 Series – Power Transformers (General, Temperature Rise, Insulation, Reactors)
• IEC 60850 – Railway Applications: Supply Voltages of Traction Systems
• IEC 61373 – Railway Applications: Rolling Stock Equipment - Shock and Vibration Tests
• IEC 62498-1 – Environmental Conditions for Equipment Onboard Rolling Stock
• ISO 3746, ISO 9614 – Acoustics: Sound Power Levels and Sound Intensity Measurements

Ensuring transformers and inductors meet the requirements of IEC 60310:2026 and related standards is key to safe, interoperable, and efficient railway systems in an increasingly interconnected transport sector.