& nbsp; 1. Insulating materials in insulating structures
& nbsp; & nbsp; & nbsp; & nbsp; marking an electrical product as a heat-resistant grade does not mean that every insulation material in the insulation structure of the product has the same temperature limit. The temperature limit of insulating structure may not be directly related to the temperature limit of each insulating material. In the insulation structure, the temperature limit of the insulation material may be increased by the protection of other components, or the temperature limit of the insulation structure may be lower than the temperature limit of each component due to the incompatibility of materials.
& nbsp; & nbsp; & nbsp; & nbsp; 2. Temperature and temperature rise
& nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp In determining the measurement methods and allowable temperature rise in such standards, the following factors should be taken into account, such as structural characteristics, thermal conductivity and thickness of insulation, detectability of insulation parts, ventilation method, load characteristics, etc.
& nbsp; & nbsp; & nbsp; & nbsp; 3. Service life of insulating materials
& nbsp; & nbsp; & nbsp; & nbsp; the actual life of electrical products depends on the specific conditions in operation, these conditions can vary greatly with the environment, work cycle and product type. For some electrical products, because of their specific application purposes, the service life of insulation is required to be lower or higher than the normal value, or because of the special operation conditions, it is stipulated that the temperature of insulation is higher or lower than the normal value, so that the temperature of insulation is extremely higher or lower than the normal value.Insulating materialsIts service life depends largely on its isolation from oxygen, humidity, dust and chemicals. At a given temperature, the service life of properly protected insulators is longer than that of freely exposed insulators. Therefore, the use of chemical inert gases or liquids as cooling or protective valences can prolong the service life of insulators.
& nbsp; & nbsp; & nbsp; & nbsp; 4. Limitation of working temperature
& nbsp; & nbsp; & nbsp; & nbsp; in addition to aging, some insulating materials will soften or deteriorate when heated beyond a certain temperature, but their original properties will be restored after cooling. When using such materials, care must be taken to ensure that they work within the appropriate temperature range.