Insulation classes and limit temperatures
The classes of insulating materials divide these materials into temperature ranges for which they are suitable. The insulating materials lose their efficiency due to the constant heat loss of the transformer. This chemical aging process is exponentially accelerated with increasing temperature. Therefore, one must use insulating materials and impregnating agents of the appropriate class of insulating material to achieve a sufficient life of the insulation. Further information on the classes of insulating materials can be found in the EN60085.