It is extremely important to stress that the temperature limit of an insulation system may not be directly related to the thermal capacity of the elements used in the system individually. Therefore, the insulation system of electrical components are based on the composition of different insulation materials used in electrical devices. https://www.mrosupply.com/motors/ac-motors/single-phase-motors/2526153_12006700_leeson/ This composition in an electric motor takes place through wire insulation enamel, groove bottom, groove closure insulation, insulation between phases, varnish and impregnation resin, insulation of the connecting cable and solder insulation.
Thus, the characteristics of any elements found in a given thermal class does not make each insulating element used in its composition, obtain the same thermal capacity. The maximum temperature limit for an insulation system can not be directly related to the thermal capacity of the elements used. Regardless of the system, the thermal performance of a component can be improved through the protective specifications of some materials used with this material. The characteristic of a given product of any thermal class may not mean and that each insulating material used in its construction has the same thermal capacity or class.