Tan Delta and partial discharge diagnostics are critical techniques for assessing the health of underground power cable networks. Tan Delta testing measures the dielectric dissipation factor of the cable insulation, which indicates the level of degradation and moisture content. This helps in identifying aging cables that may be at risk of failure. Partial discharge testing detects small electrical sparks occurring within the insulation of the cables, which are early signs of insulation breakdown. By performing these diagnostics, utilities can detect and address potential issues before they lead to catastrophic failures, thereby enhancing the reliability and longevity of the underground power network.