Abstract :
An important theme underlying the paper is consideration of the degree to which it is practicable or desirable to render interchangeable the numerous outdoor bushing designs now available for any given service, and to effect any measure of standardization. In developing this theme, much of the paper is devoted to the subjects of construction and testing. The paper first analyses the existing variations in construction from all aspects and discusses the relative advantages of a large number of different features of the principal types of outdoor bushings. The variations of test and service conditions which control design are then studied. Ideal test conditions are enunciated and in the light of them the author considers the tests which modern bushings have to meet. The effect of these latter tests upon design and construction are examined. Hence recommendations are made regarding the lines upon which it would be advantageous to standardize test conditions. Finally, the mechanical interchangeability of bushings is discussed and a degree, of standardization proposed. Whilst the paper relates mainly to transformer and circuit-breaker terminal bushings, and gives prominence to bushings of the bakelized-paper condenser type, it by no means confines consideration to these, and most of the conclusions are of general application.
