IEC 60455-2:2015

Overview

IEC 60455-2:2015 - "Resin based reactive compounds used for electrical insulation – Part 2: Methods of test" - specifies standardized test methods for both uncured (reactive) resin compounds and their cured counterparts used in electrical insulation applications. This third edition (2015) updates the 1998 edition, introduces test methods related to IEC 60455-3-8, and adds/updates test procedures for resins. The standard is essential for objective evaluation of material properties, quality control, and product development for insulation resins, potting compounds, cast insulating parts and cable accessory materials.

Key topics and technical requirements

The standard defines practical laboratory procedures and reporting conventions for a wide range of material properties, including:

• General test preparation and conditioning: specimen preparation, sequence of tests and test reporting.
• Tests for reactive compounds and components:
  • Flash point, density, viscosity (including viscosity after elevated storage), volatile organic content (VOC)
  • Isothermal viscosity increase (processing time), pot life and gel time
  • Shelf life, softening point, filler/ash content, chlorine content, water content (Karl Fischer)
  • Chemical metrics: epoxide equivalent, hydroxyl/acid/amine values, double-bond content, isocyanate content
  • Special procedures: curing behavior (including curing in presence of water), exothermic temperature rise, total volume shrinkage, degree of curing
• Tests for cured compounds:
  • Mechanical: tensile, compressive, flexural, impact, hardness
  • Thermal: glass transition (Tg), thermal conductivity, linear thermal expansion, thermal shock, flammability, temperature index, dry/wet heat resistance
  • Chemical: water absorption, resistance to liquids and mould growth, water vapour permeability
  • Electrical: volume resistivity, dielectric dissipation factor (tan δ) and permittivity, breakdown voltage/electric strength, proof tracking index (PTI), electrolytic corrosion
• Health and safety considerations (informative annex)

Practical applications and users

IEC 60455-2 is used by:

• Manufacturers of resin-based insulations, potting and casting compounds for product specification and quality control
• Test laboratories and certification bodies performing type tests and compliance verification
• R&D teams developing new resin formulations or optimizing processing (pot life, gel time, curing)
• Specifiers and purchasers in power, cable accessories, switchgear, transformers and electronics to ensure material performance and comparability
• Regulatory and safety engineers assessing thermal, electrical and chemical resilience of insulating materials

Related standards

• IEC 60455 series (other parts defining product specifications and applications)
• Specifically referenced: IEC 60455-3-8 (test methods introduced in this edition)
• Users should review normative references cited within IEC 60455-2 for complete test applicability.

Keywords: resin based reactive compounds used for electrical insulation, IEC 60455-2:2015, methods of test, pot life, gel time, dielectric strength, thermal properties, quality control.