The purpose of this document is to establish principles for the development of test procedures to evaluate the thermal stability of insulating materials for electrical uses and of simple combinations of materials used in rotating electrical machines, transformers and other types of electrical equipment. The results of accelerated thermal stability tests, performed in accordance with these test procedures, can be used as a guide in assigning new insulating materials to the appropriate temperature classes. Test methods should be developed for each major class of insulating material, such as wire enamel, sheet insulators, etc. The results of tests on known and widely used materials should be compiled for reference purposes so that comparisons between old and new materials can be easily established. The important points to be taken into account in the development of test procedures are described in this document. The objective of the test procedures is to provide methods for determining the relative thermal stability of insulating materials. The data obtained should serve as a basis for establishing a thermal classification for materials and for selecting insulating materials for electrical equipment. Test procedures should also provide methods for determining the rate at which important properties of materials degrade in relation to thermal aging. To perform satisfactorily, insulating materials must simultaneously present the required combination of physical, chemical and dielectric properties. Such properties must be evaluated separately by test methods not included within the scope of thermal stability test procedures. Methods
COVENIN 861-1976 history
1976COVENIN 861-1976 Test method for thermal stability of electronic insulating materials