Field experience with non-ceramic hollow-core insulators

This paper reports on field experience with AC-energized hollow-core polymeric insulators. The paper presents the leakage current performance and the hydrophobicity status of the insulators. For the purpose of reference, a hollow-core insulator made of porcelain is also included in this paper. The insulators were mounted in both an upright as well as an inclined position. Also, the specific creepage paths of the insulators were relatively low, in the order of 12.4 to 14.7 mm/kV only. The presented results refer to a period of four years. The obtained results show that there is a clear difference in the performance between the upright and the inclined insulators. The inclined insulator has somewhat higher leakage currents, In addition, the hydrophobicity is lower on the underside of the inclined insulator