Test of Surface Electrical Failure of Organic Insulators by Means of Intermittent Discharges from a Capacitor

The recent introduction of numerous organc and semi semi-organic electrical insulating materials emphasizes the need to n investigate tracking resistance. Many test methods for the purpose of testing the surface failure of insulating materials have been e devised; each one has some advantage and fault due to the required test conditions. Consequently it seems difficult to choose the standard rd method for the evaluation of tracking resistance. The IEC recommended test method [1] for the property has been thought to be a reliable method until now, however even the IEC method has some faults. It is not suitable for testing materials having high tracking resistance, and the electrolytic solution dropped on the surface of insulator specimen may influence test results differently depending on the sorts of materials tested. The authors carried out a study on the dry test method of surface electrical failure of organic insulators with a view to eliminating the faults described above, and compared it with other test methods.