Abstract :
This paper constitutes a theoretical investigation of the effect of insulation variability in determining the breakdown voltage of systems containing large areas of insulation, or large numbers of units of insulation in parallel. It is based upon the idea that a failure in the insulation of a system, like that of a chain, depends upon the strength of the weakest part, or unit; and that the greater the number of units in a system and the greater the variability among the units the greater will be the likelihood of a failure. The analysis, therefore, makes use of the laws of probability which incidentally are more exact and of greater practical importance than is generally believed.
