Development of a method to evaluate deterioration degree of low-voltage PVC sheathed cable

In this paper, in order to develop the diagnostic technique, we deteriorated the low-voltage cables acceleratively under some thermal conditions and investigated the correlations related to elongation which could be considered as a value of degradation degree. As the experimental results, we found that the diagnostic technique of the equotip hardness method has its merits of nondestruction, small error and simplicity. Moreover we investigated the correlation between the equotip hardness and the elongation at break of PVC sheaths of several low-voltage cables, and obtained the master curve between equotip hardness and elongation. And then we developed the diagnostic apparatus based on the equotip hardness method.