| 摘要 |
PURPOSE:To eliminate the possibility of parallel operation under asynchronous condition of a plurality of AC power supplies by providing means for detecting terminal voltage of load, means for judging whether an inverter is normal or not, and a circuit tor closing a switch if the load has no voltage and the inverter is normal. CONSTITUTION:AC output from an inverter 3 is fed through an electromagnetic contactor 5 to a load 6 and a voltage detecting relay 12 is connected with the load 6. It a contact 4A closes when an inverter circuit 4 is normal, a contactor coil 13 is excited through a power supply 11 to close the electromagnetic contactor 5 so as to feed AC power from the inverter 3 to the load 6. When an abnormality occurs in the inverter circuit 4 and the contact 4A is closed, the electromagnetic contactor 5 is opened and power supply from the inverter 3 is stopped. By such arrangement, possibility of parallel operation of a plurality of AC power supplies under asynchronous state can be eliminated. |
