| 摘要 |
PURPOSE:To strengthen the protecting function of a voltage type inverter by providing single-phase voltage detecting time limit relays in two phases except the phase in which a rapid disconnection fuse with a switch is provided, and providing a main contactor for connecting the fuse directly with a 3-phase power source at the relay operating time. CONSTITUTION:A rapid disconnection fuse 15S with a trigger switch which outputs a signal by detecting a fuse melting disconnection is provided in one phase, normal rapid disconnection fuses 15R, 15T are provided in the two phases except the one phase, and single-phase voltage detecting time limit relays 10 are connected in the other two phases. When the fuses 15S, 15T are melted and disconnected, the relays 10 are turned OFF to open a main contactor 2. When the fuse 15S is melted and disconnected, its normal close contact 16 is opened. Thus, a controller is disconnected from control power sources P, N and the coil 12 of an auxiliary contactor 8 and the coil 14 of the contactor 2 are forcibly deenergized to open the contactor 8 and the contactor 2. |
