<![CDATA[Porcelain insulators are essential components in electric power transmission and distribution systems, functioning to electrically isolate conductors while preventing leakage current. The performance of porcelain insulators can deteriorate due to environmental contamination, particularly volcanic ash in areas affected by the eruption of Mount Marapi. This study aims to analyze the effect of natural volcanic ash contamination on the insulation resistance of a 20 kV porcelain insulator under different moisture conditions. An experimental method was employed by measuring insulation resistance using an insulation tester with a 5 kV DC test voltage. The tests were conducted under four conditions: clean insulator, dry volcanic ash contamination, moist volcanic ash contamination (16 gr of volcanic ash with 5 mL of water), and wet volcanic ash contamination (16 gr of volcanic ash with 10 mL of water). Each condition was tested ten times, and the measurement results were analyzed using descriptive statistics, including the mean, standard deviation, and percentage reduction in insulation resistance. The results showed that the average insulation resistance decreased from 1010.6 MΩ under clean conditions to 885.7 MΩ under dry volcanic ash contamination, 567.6 MΩ under moist volcanic ash contamination, and 219.8 MΩ under wet volcanic ash contamination. Compared with the clean condition, the insulation resistance decreased by 12.36%, 43.83%, and 78.25%, respectively. The findings indicate a decreasing trend in insulation resistance as the moisture content of the volcanic ash increased. These results provide useful information for the inspection and maintenance of porcelain insulators in substations located in volcanic ash-prone areas.]]>
