Abstract :
Many factors affect the flashover characteristics of porcelain insulators; these characteristics in turn have a direct bearing upon insulator design and upon the choice of proper insulation for any particular purpose. In the following group of three articles by representatives of three of the leading insulator manufacturers, results of investigations made in this field by these manufacturers are given. In the past, many of the data for comparable insulators from different sources seemed conflicting. In these articles, however, reasonably careful study will reveal many points of agreement, when the results are reduced to a comparable basis. The first two articles deal with the effect of various factors on insulator sparkover characteristics; the third article deals with the flashover characteristics of suspension insulators, and also contains data relating to the cost and selection of economical suspension insulator assemblies.