& nbsp; evaluation of heat resistance of insulating materials
& nbsp; many insulating materials of the same genus can vary in heat resistance. Therefore, it is inappropriate to judge the heat resistance of insulating materials according to their chemical names.
& nbsp; various insulating materials used in the insulation structure of electrical products, their respective heat resistance may be affected by other materials. In addition, the heat resistance of various materials depends to a large extent on their specific functions in the insulation structure.
& nbsp; in terms of the use of insulating materials in electrical products, material evaluation has two purposes: one is the evaluation of a material as an integral part of an electrical insulation structure, the other is the evaluation of a material used alone or as an integral part of a simple combination of insulating structures.
& nbsp; generally, the evaluation test and operation experience are recognized as the acceptable basis for the evaluation of heat resistance of insulating materials.
& nbsp; on the basis of operational experience, it should be noted that the experience must be guaranteed to be applicable. But in some cases, it may also be appropriate to apply one experience to another. Appropriate methods should be developed to determine the relationship between operational experience.
& nbsp; for a material, different properties (such as electrical, mechanical, etc.), methods and failure criteria are used to make heat resistance diagrams, and different temperature indices and half-deviations may be obtained. Different temperature indices and half-deviations indicate that the heat resistance is different, which determines the way the material is used and the functions it can undertake.
& nbsp; the results obtained by standard sample test may be different from those obtained by material test according to its actual use form. The insulation structure is closer to the actual situation. Therefore, the results of insulation structure test can prove the applicability of materials in related applications.