Insulation temperature standards for industrial-control coils

G. H. Garcelon (Westinghouse Electric and Manufacturing Company, East Pittsburgh, Pa.): Mr. Erikson´s paper brings out a condition that certainly requires some action. The performance record of industrial-control coils has been good in spite of the fact that the prescribed temperature limits are in excess of those recognized for rotating machinery. This record also includes many years when the insulating materials and processes were inferior to those in use today, and, with the advent of the new materials and techniques, it is definitely in order to develop standards permitting higher temperature rises.