Comparison of surface tracking in polymeric insulating materials

A study was undertaken to investigate the surface tracking phenomena in different polymeric insulating materials. The polymeric materials chosen were silicone rubber (SR), ethylene propylene diene monomer (EPDM), polypropylene and high density polyethylene (HDPE). The tracking test was conducted as per IEC (587) standard under AC and DC voltage with ammonium chloride as the main contaminant. The CCD camera was used to record the progress of tracking. Leakage current was measured by digital storage oscilloscope. Tracking time for each material was observed with different test conditions and comparison was made. Based on the comparison, it could be concluded that silicone rubber has got superior performance to tracking compared to other three materials.