Effects of adding rate on dc tracking failure of epoxy/MgO nano-composites under contaminated conditions

Nano-MgO particles were added in epoxy with particle weight ratios of 1, 3, 5, 7 wt%. Tracking experiments were carried out by using dc voltage. The tracking process was recorded by a high speed camera. The relation of tracking failure with the adding rate and applied voltage was investigated. Obtained results indicated that with increasing adding rate from 0 to 5 wt%, number of drops needed in tracking failure increased, the weight loss of nanocomposites and area of tracking pattern decreased. The opposite varying tendency was obtained with increasing the adding rate from 5 to 7 wt%. Finally, experimental results suggested that tracking resistance of epoxy could be improved by adding nano-MgO particles and the best improvement was obtained at 5 wt% adding rate.