| 摘要 |
PURPOSE:To separate and remove a fibriform filth by electrically detecting increase in load applied to a motor when said fibriform filth has windingly deposited, and reversing said motor for a certain period of time by means of a control unit. CONSTITUTION:A control unit 7 detects an ordinary current value in the normal rotation of a motor 2 by means of an ammeter 6. When increase (the limit of increase is previously set) in the value is detected, this increase is regarded as increase in load due to a windingly deposited fibriform filth around the rotary part of a pump 1. Therefore, when increase in current is detected, the control unit 7 switches a polarity changeover switch for a certain period of time to reverse the motor 2, which then, is returned again to the normal rotation. The fibriform filth which is windingly deposited around the pump 1 is usually separated by this reverse rotation but, when the filth is not sufficiently separated, the measured value of the ammeter 6 is not lowered and the reverse rotation is repeated. When the reverse rotation is repeated for a certain number of times and, yet, if the current value is not restored to the normal value at the time of normal rotation, the motor 2 is stopped and an alarm is driven to issue an alarm.
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