This paper presents the study on the effects of oil palm empty fruit bunch (OPEFB) micro-filler on electrical tree
propagation in silicone rubber composite material. In this study, the oil palm empty fruit bunch (OPEFB) filler with mean
size of 32 μm was employed as an electrical tree inhibitor. The sample for this electrical tree experiment was in the form
of leaf-like specimen which was characterized as filled sample and non-filled sample. The filled sample contained 1 wt%
of OPEFB filler while the non-filled specimen contained no fillers. Obtained results show that the lengths of electrical
trees in filled silicone rubber were shorter than tree length of non-filled silicone rubber for 60 minutes propagation time.
This tree length difference shows that the OPEFB micro-filler helped to retard the growth of electrical tree. Therefore, this
new organic filler is found to be useful for electrical tree inhibitor in high voltage insulation.