| 摘要 |
PURPOSE:To detect the thermal deterioration degree of the insulated electric wire of actually operated machinery, by calculating the thermal deterioration degree as the functions of temp. and a time from the change in the hardness ratio of an insulating coating comprising the same material as an insulating apparatus to be measured and comparing said hardness ratio with that of the insulating coating of the insulated electric wire used in the actually operated machinery. CONSTITUTION:When a specimen is deteriorated at 120 deg.C, 130 deg.C and 150 deg.C to calculate a hardness ratios before and after deterioration, the hardness ratios increase with the advance of deterioration. A conversion time theta and hardness h being measures of deterioration take unique relation represented by theta=f{M<1>-(h)} and the time theta becomes large as deterioration advances. Now, when an electric wire is bent at the same bending diameter as the diameter of said wire and a heating time required for confirming the crack of a rubber coating layer is set as life, it is judged that a hardness ratio was ha and 1.0 is graduated on the deterioration degree axis being the axis of abscissas of the conversion time thetae corresponding to said hardness ratio to be set as a life point while the same material as the specimen is used as the lead wire of a rotary machine and hardness ratio after operation for a required time is calculated. When this hardness ratio was hb, the conversion time thetab, the conversion time thetab is obtained from the intersecting point on a curve and the degree of the thermal deterioration of the lead out wire of the rotary machine can be detected from the graduations of the deterioration degree corresponding to said conversion time thetab. |
