DETECTOR OF LOCAL ELECTRIC DISCHARGE ON ELECTRIC APPARATUS

PURPOSE:To surely detect a local discharge by simultaneously detecting signal components corresponding to interlinked magnetic field components arranged near the winding and a decomposed gas produced by the local discharge. CONSTITUTION:When an outcoming radio wave or noise are generated, they come to a local discharge sensor 5, which most possibly responds thereto. But, a signal is not outputted from a decomposed gas sensor 7 in this case by the reason that no decomposed gas is produced, therefore, the signal is not outputted to a display device 11 for abnormal signal through a signal processing device 10. On the other hand, the sensor 7 responds when the decomposed gas is produced in the sensor 7 by a primary factor other than the local discharge and is responded. In this case, however, an abnormality is not displayed the same as before, since the sensor 5 is not responded. Thus, the local discharge only can be surely detected by the combination of the sensor 5 and sensor 7.