Live-line maintenance of AC overhead lines equipped with non ceramic insulators (NCI)

The paper makes a qualitative/quantitative analysis of the defects which may affect the possibility of Live-Line Working (LLW) on overhead lines equipped with Non-Ceramic (NCI) or composite insulators. Diagnostic techniques available at present for the detection of such defects are evaluated. It is shown that the present level of accumulated knowledge and the available diagnostic tools make it possible to assess the conditions of NCIs and to assure safe LLW for the overhead lines equipped with NCIs.