Evaluation of the insulation of 15 kV-25 kV feeders and procedures for substitution of damaged units

The aim of this paper is to define some steps in the process of defining an efficient field procedure to determine the operational condition of porcelain pin insulators. This will assist the maintenance of the distribution networks and the substitution of failed insulators. Considering the technical and economic aspects, two technologies of relatively low cost and easy operation have been applied, detection of ultrasonic and radio interference noises. The results obtained in field inspections are compared with several tests carried out at the high-voltage laboratory of Federal University of Itajuba. From these comparisons an analysis, the effectiveness of each technology applied to the field research is obtained.