| 摘要 |
<p>In a main circuit, a power supply, a line breaker (5), a power converter (7) and motors (8 to 11) are connected in series. The line breaker is thrown in at the beginning of the operation and remains thrown in till the end of the operation unless it is accidentally opened by, for example, an overcurrent. A control apparatus includes a control signal generator (14) for applying a gate signal (13) to the power converter, and a diagnostic section (34). When the operator manipulates to issue a running start command (20), the control signal generator and diagnostic section receive this command separately. When receiving the command, the diagnostic section transmits a permission signal to the control signal generator. On condition that the control signal generator receives by itself the running start command and the permission signal, the control signal generator delivers the gate signal to the power converter.</p> |
