Functional life tests of apparatus as compared with insulation material tests

Experimental work by users and manufacturers of electric equipment alike, has disclosed the need for an entirely new concept of insulation classification and evaluation. It is found that insulations should be classified as systems as well as materials. The manner in which the materials are applied and processed is of as equal an importance as the basic materials used. The electrical industry, working through the AIEE, developed the concept of functional evaluation of insulation systems. This concept appears in AIEE No. 1, published in June 1957.1