Introduction: UK Power Networks experiences faults on Low Voltage (LV) and High Voltage (HV; Note 6.6 or 11kV) underground cables each year, with over 80% of these faults attributed to “age and wear” or “unknown” causes. A previous study on an NIA project, “Prediction of weather-related faults”, showed that there was a measurable relationship between the amount of rainfall and the number of LV and HV faults. However, the previous study also showed that further work was required to develop an operational faults forecast model for LV and HV underground cables. A review of soil characteristics in combination with rainfall is likely to provide additional detail to be able to develop an operational faults forecast model. The data on soil characteristics can also be used to develop a soil resistivity assessment tool, for secondary substation earthing studies.

Objectives: The objectives of this project include:

1.     To determine the relationship between soil type, rainfall and underground cable faults
2.     To build a faults forecast model for underground cables (if a meaningful relationship exists between soil type, rainfall and underground cable faults)
3.     To build a soil resistivity assessment tool for desktop earthing assessments at substations