Three decades of progress in electrical insulation

THE LAST 30 YEARS was a period marked with outstanding advances in certain areas of the field of electrical insulation. This period began with what might be termed the “synthetic chemical age” and ended with the start of the “space age.” The progress made during the period may be divided into the following four categories: (1) advances in understanding and application of dielectric theories, (2) development of a host of new synthetic materials, (3) creation of a new system of classifying materials and the revision of the electrical insulation temperature standards, and (4) application of new insulating materials to electrical equipment.