Gaseous Insulation for High-Voltage Transformers [includes discussion]

It is well recognized that sulfur-hexafluoride (SF6) possesses, even at relatively low pressures, superior insulating properties for high-voltage apparatus. Under certain conditions the dielectric strength of this gas can be superior to either liquid or solid insulating materials. During the last few years much experimental work has been done on the electrical and chemical properties of this gas. These and other pertinent data are presented herewith. Of particular importance are the data obtained on the physiological effect of the decomposition products of SF6 gas when it is subjected to heavy short circuit arcs between bare electrodes and also in the presence of other insulating materials.