Basic impulse insulation levels

ONE of the early steps taken by the electrical industry, in an attempt to help solve the insulation-co-ordination problem was the formation of the National Electric Light Association (now Edison Electric Institute)-National Electrical Manufacturers Association Joint Committee on System Insulation Co-ordination in 1931. Before relating the work done by this committee, to acquaint the industry with what has been done to date and the present status of the work, it may be well to comment briefly, on what is meant by “insulation co-ordination.”