Diagnostics using dissipation factor measurement with a 0.1 Hz sinusoïdal voltage provides information on the ageing characteristic of PE/XLPE cables. Differentiation is made between new, lightly and heavily water-tree damaged cables. In this way a priority for cable replacement can be determined. The combination of the programmable test generator, PHG 70 or PHG 80, with the BAUR dissipation factor measurement system results in the cable test and diagnostic system PHG TD. The system is operated via the PC controller. In the Dissipation Factor Measurement menu, diagnostic sequences can be programmed. The dissipation factor values are measured at different voltage levels and are then evaluated for differential TD. Important cable data can be stored, so that step-by-step, a cable database is created which enables evaluation of the diagnostic results on the basis of the historical evolution of a cable system. In the TD main menu all essential data is summarised. In addition to the information on the prevailing voltage, the test phase, actual capacitive load, measured values of current and voltage, the prevailing dissipation factor value and the mean dissipation factor value are displayed. As supplementary information, measuring value fluctuations are obtained and displayed via the determination of the standard deviation of the values at the nominal voltage level. The leakage current display in μA serves as a check to any parasitic currents.

The PHG TD system is available in several variants. In addition to the cable test van version, the system is upgradeable to a partial discharge measuring system and also available as stand-alone unit mounted on a European standard pallet. BAUR can offer separate leads and adapters to meet the different connections that are found within the various substation configurations.