New class H insulation for rotating equipment

A physically tough hybrid inorganic/organic paper is being used as high-temperature electrical insulation in class 180(H) transformers. As a laminate with polyester film, this same hybrid paper material can also be used as slot and wedge insulation for rotating equipment. Background on the high-temperature paper, a hybrid composed or inorganic materials reinforced by a combination of organic materials, is presented, including data on the thermal aging characteristics of the paper. Electrical, mechanical, and thermal properties of the composite lamination are compared to those of other flexible electrical insulation materials. Practical application information pertaining to the laminate is also presented