Hazards of Interpretation of Dissipation-Factor Tip-Up Deterninations

Several contributions to the study of empirical correlation between tip-up and insulation life are reviewed. In addition to the published literature some previously unpublished field measurements are cited. Some investigators report favorable correlation while others report the contrary. Our own experience on two different insulation systems indicates that the extent and the nature of correlation is dependent on the kind of insulation system which is being evaluated. It is concluded that tip-up determinations can have their uses in weeding out unusual and atypical insulation. The absolute level of tip-up will be a function of the kind of insulation system being tested, and variations among systems can be completely uncorrelated with performance.