SYSTEM DISCRIMINATION DEVICE

PROBLEM TO BE SOLVED: To provide a discrimination device for an electric circuit system connected between one line of an electric circuit (voltage-side line or earth-side line) and the ground and capable of positively discriminating the system. SOLUTION: The system discrimination device includes: means 501, 502 for detecting a zero phase current of an optional system in the upstream and a means 503 for determination upon determination of the connection system in the upstream and the downstream of a plurality of distribution systems on a load-side of a transformer 1 having a secondary winding with one terminal connected to the ground; and a voltage detection discrimination means 603 connected between one terminal of a wiring of an optional system in the downstream and the ground, an impedance 604, a voltage generation means 605 and a connection switching means 606. Based on a predetermined condition, the impedance 604 or the voltage generation means 605 is selected to be connected. When the voltage detection discrimination means 603 determines that the detected zero phase current is obtained by connecting the impedance 604 or the voltage generation means 605, the system of the wiring or a device on which the discrimination device is disposed is determined to be the same. COPYRIGHT: (C)2010,JPO&INPIT