| 摘要 |
PURPOSE:To improve the reliability of a system by providing a plurality of controllers having self-diagnosing function in a controller of a frequency converter. CONSTITUTION:Nos. A and B controllers 43A, 43B having a self-diagnosing function controller 40 having a simulating current feedback forming circuit, a simulating synchronous motor speed feedback forming circuit are provided in a thyristor starter control board 45. When a starter controller check command is applied from a controller 44, it first checks the No.A self-diagnosing function controller, and if the No.A is normal, it finishes the check, and actually starts by the No.A controller. If the No.A is abnormal, the self-diagnosing function controller is automatically switched from the No.A to the No.B. If the No.B is normal, it finishes the check, and actually starts by the No.B controller. if the No.B is abnormal, the start is stopped, and the defective portion is observed. |
