Investigation of Electrical and Mechanical Properties of Low Voltage Power Cables under Thermal Stress

In this research work, the behavior of low voltage unshielded power cables used in nuclear power plants is investigated under thermal stress. The cables were subjected to 120°C for eight accelerated aging cycles with jacket and insulation in contact. The electrical integrity of the cable was studied by measuring capacitance and tanδ for a frequency range of 10 mHz to 1 kHz. While the mechanical properties were studied using Shore D hardness test. A significant increase of tanδ above at 10 Hz was observed which is associated with interfacial polarization. While an increase in hardness of the cable was also noted. The characteristic response of the cable under thermal aging was associated with the degradation in the amorphous region of the polymers in comparison to the crystalline region. The experimental results show the potential of the adopted non-destructive techniques to be used as a good diagnostic method.