| 摘要 |
A pump apparatus comprising a mechanically switched pump, such as a direct online/star delta pump, capable of being operated in a forward and a reverse direction and a control comprising a monitoring mechanism to monitor the torque of the pump and a control mechanism which makes the pump stop and/or operate in a reverse direction when the monitoring mechanism detects the pump operating at a pre-determined value of torque. The control system is used to provide anti-ragging functionality to remove blockages. Preferably the control mechanism performs a series of reverse and forward cycles when the predetermined value of torque is detected, the time of each stage of the cycle may be 1-20 seconds or be preset by the user. The monitoring mechanism may calculate the torque by measuring the current draw, alternatively a torque instrument could be attached to the motor shaft. |
