Condition assessment of service aged XLPE distribution cable

As a result of a voltage conversion from 12 kV to 25 kV at Manitoba Hydro, a significant amount of 15 kV XLPE cable, approximately 25 years of age was abandoned. The opportunity was taken to carry out diagnostic tests consisting of leakage current measurements, location and detection of deterioration in the concentric neutral, and location and quantification of partial discharge sites. Following this, 0.1 Hz breakdown tests were done. Similar amounts of the cable were tested with 0.1 Hz sine wave and 0.1 Hz cos-rectangular waveform. The paper reviews the findings of these tests and their applicability for maintenance purposes.