IEC 60216-6:2022

Overview

IEC 60216-6:2022 - part of the IEC 60216 series - defines the fixed time frame method (FTFM) for deriving thermal endurance indices of electrical insulating materials. It specifies experimental procedures and calculation methods to obtain the Temperature Index (TI) and Relative Temperature Index (RTI) based on thermal ageing at a set of fixed times and multiple temperatures. This third edition (2022) clarifies index vs. endurance property definitions, restricts diagnostic tests to destructive tests, and includes a complete rework of Annex G (computer program guidance).

Keywords: IEC 60216-6:2022, thermal endurance, TI, RTI, fixed time frame method, electrical insulating materials, thermal ageing.

Key topics and requirements

• FTFM protocol: Age specimens for a prescribed set of fixed times across multiple ageing temperatures; measure properties at the end of each time interval.
• Diagnostic tests: Limited to destructive tests (proof and non-destructive procedures not covered by this edition).
• Property selection: Distinguishes index properties (used for TI/RTI calculation) from endurance properties (properties that degrade during ageing).
• Statistical and calculation procedures: Regression analyses, equivalence of property values to temperatures, variance and linearity tests, confidence limits and extrapolation methods are specified.
• Reporting: Mandatory content for result reporting, including statistical test summaries and thermal endurance graphs.
• Supplementary material: Annexes provide decision flow charts, suggested ageing times/temperatures (e.g., TI correlation time guidance such as 20 000 h), statistical tables and a reworked Annex G with computer program examples for IEC 60216-6 calculations.

Keywords: thermal endurance calculation, regression analysis, destructive diagnostics, ageing temperatures.

Applications and users

IEC 60216-6:2022 is used by:

• Material manufacturers and R&D labs for material qualification and comparative performance assessment.
• Test laboratories performing thermal ageing and lifetime prediction for insulation materials.
• OEMs and design engineers selecting insulation materials to meet service temperature and lifetime requirements.
• Certification bodies and standards committees creating product specifications and compliance demonstrations.

Practical uses include predicting service life, determining TI/RTI for material datasheets, comparative screening of formulations, and supporting end-of-life or warranty assessments.

Keywords: insulation materials testing, lifetime prediction, service temperature rating, TI determination.

Related standards

• IEC 60216-1 - the companion method where ageing is done at fixed temperatures and property measurement is time-dependent (contrast to FTFM).
• Other parts of the IEC 60216 series covering definitions, general principles and alternative procedures for thermal endurance testing.

Use IEC 60216-6:2022 when applying the fixed time frame method to derive TI and RTI and when destructive diagnostic tests are acceptable for assessing thermal endurance.