| 摘要 |
PURPOSE: To provide a load circuit protective device which can automatically judge abnormality of a protective characteristic when a load circuit is stopped. CONSTITUTION: A load circuit protective device is provided with a load to which electric power is supplied through a power line connected to a bus bar, a contactor 3 inserted into the power line, electric current detecting means 5 and 6 to detect electric current informations Va and Vb from the power line and a load circuit protective means 11 to trip the contactor when abnormality of the electric current informations is detected. The load circuit protective means is provided with an input means 11i using an opening-closing condition of the contactor as input information, a voltage generating means 11e to generate a voltage signal Vc corresponding to an abnormal value of the electric current informations, an output means 11h to control so as to open and close the contactor and an operation storage means 11m to control the voltage generating means and the output means on the basis of the electric current informations and the input information. The operation storage means takes in the voltage signal when the contactor is opened, and diagnoses a protective function on the basis of time until the contactor is tripped. |
