Abstract :
Loss in strength is a function of conductor maximum temperature which, itself, is a function of I2t. Instead of producing currents and times as they may occur in the field, one can, in the laboratory, choose more convenient values giving the same I2t, the same maximum temperature and the same loss in strength. Using this approach, diagrams were developed showing, for electrically equivalent copper and aluminum conductors, the current-time relations producing specific degradations.