Development of the assessment procedure to evaluate the performance of High Voltage Insulator Coating (HVIC)

Distribution Division of Tenaga Nasional Berhad operates and maintains all the distribution networks in Peninsular Malaysia. The overhead distribution lines pass through the major air pollution sources such as: marine, industrial, and agricultural. Due to this, the overhead networks are exposed to different environmental exposure leading to different types and degree of damage. There are 2 modes of insulator failures; flash over phenomenon and corrosion. A coating material was identified based on its usage and performance in other utilities. In this project, a procedure was developed to evaluate the performance of the coating material. The suspension type insulators were selected and coated, and tested for hydrophobicity, surface gloss and thickness. In addition, the Estimated Salt Deposition Density (ESDD) measurement was done at the site upon installation. The tests were repeated prior to installation at sites and after 3-4 months of installation. Three and two samples were sent to material lab to perform salt spray test and UV lab for aging process respectively. Based on the implementation of the proposed assessment procedure, it has been found that the performance of the HVIC applied on the insulators of overhead lines for 33kV distribution system for an exposure period of 3-4 months at sites was found to be not satisfactory.