DIAGNOSTIC METHOD FOR OIL-FILLED ELECTRIC EQUIPMENT, DIAGNOSTIC DEVICE FOR IMPLEMENTING DIAGNOSTIC METHOD, AND OIL-FILLED ELECTRIC EQUIPMENT WITH BUILT-IN DIAGNOSTIC DEVICE

摘要

An object of the invention is to provide a diagnostic method for an oil-filled electrical device that considers a temperature distribution in the oil-filled electrical device and enables accurate diagnosis to be conducted even when the method is applied to diagnosis of an actually operating device, and further provide a method with which such diagnosis of an oil-filled electrical device can be conducted from a component analysis value of an insulating oil (3) in the oil-filled electrical device. The invention is a diagnostic method for an oil-filled electrical device including in an insulating oil (3) a metal part wrapped with insulating paper (2), and determines that a time when a surface resistivity of a maximum precipitation site where metal sulfide is most precipitated on the insulating paper (2) reaches a preset surface resistivity management value is a time of occurrence of an abnormality.