Application of RTV Silicone Rubber coating for improving performances of ceramic outdoor insulator under polluted dondition

Ceramic insulators may severe a certain degree of pollution which may reduce their surface resistance. This paper reports the investigation results on application of Room Temperature Vulcanize (RTV) Silicone Rubber for improving the performance of ceramic outdoor insulator 20 kV to overcome the effect of environmental pollution, especially in tropical climate. The RTV Silicon Rubber coated insulator tested under various environmental conditions. The samples were put in a test chamber with controlled humidity and pollution condition. The characteristics of RTV Silicon Rubber coated insulator were analyzed, such as its leakage current (LC), hydrophobicity (indicated by measuring contact angle) and Surface Smoothness (indicated by Scanned Electron Microscopy (SEM)) of the RTV Silicon Rubber insulator surface. The LC's waveform parameters such as magnitude and harmonic content (as indicated by the total harmonics distortion (THD)) were analyzed. This paper also reports the influence of RTV application RTV Silicon Rubber on hydrophobicity and surface smoothness of the insulator surface as well the influence of those parameter on LC waveforms under polluted conditions. The experimental results showed that 3rd, 5th, and 7th harmonics were observed for symmetrical-distorted LC waveforms. RTV silicone rubber coating suppressed the magnitude of leakage current, the harmonic content of leakage current and increased the flashover voltage under various artificially - simulated pollution. These indicated that RTV silicone rubber coated insulator can maintain its hydrophobicity under various polluted condition. These experimental results will be the basis of application of RTV Silicon Rubber coated insulator under polluted conditions, especially in Indonesia.