A Comparison of Diagnostic and Condition Assessment Techniques to Detect Aging in Low Voltage Extruded Insulations

Condition Assessment Techniques for low voltage extruded cables


  • Lindsay Vasilak Student


This article compares current non-destructive, non-intrusive diagnostic and condition assessment techniques employed on electric power and control cables in nuclear power plants. The theory of diagnostic methods time domain reflectometry (TDR), frequency domain reflectometry (FDR), polarization depolarization current (PDC) and low frequency dielectric spectroscopy (LFDS) are discussed. By obtaining measurements on cables in existing nuclear power plant circuits, the results are compared for each diagnostic method. PDC and LFDS are shown to be capable of providing globally sensitive dielectric characterization results which primarily aid in the detection and discrimination of bulk thermal aging effects, radiation effects or moisture ingress in LV (low voltage) or MV (medium voltage) cable systems. LFDS and PDC results may also be utilized for baseline and trending diagnostic purposes within a cable aging management program. The combination of FDR and TDR allow a local and global assessment of the dielectric properties of the insulation material, respectively.