Factors which may affect the inclined plane classification of materials

On the basis of the inclined-plane test (IEC 587), the authors examine the factors which may affect the inclined-plane classification of insulating material. The ways in which series resistance and contaminant flow rate affect the classification of material in a test circuit are enumerated, and the relationships between test voltage, series resistance, and contaminant flow rate are examined. Factors that should be considered when choosing the flow rate and series resistance are identified