GB/T 11026.7-2014

This part of GB/T 11026 proposes testing and calculation procedures for obtaining the relative heat resistance index of materials, with the test data used in this process obtained in accordance with GB/T 11026.1 and IEC 60216-2. These calculation procedures are a supplement to the calculation procedures in IEC 60216-3. This part also provides an evaluation of thermal aging at a single fixed time and temperature without inference. In principle, test data can be obtained from destructive, non-destructive, and verification tests. However, destructive tests are more widely used. Data obtained from non-destructive or verification tests may be incomplete, as the measurement of the time to reach the end point may have stopped at a certain point after the median time, before all samples have reached the end point. Based on the thermal aging performance, this part provides a preliminary allocation of thermal classification for insulating materials. When thermal stress is the main factor of aging, the calculation procedures in this part are also applicable to determining the thermal classification of electrical insulation systems.