Overcurrent during the startup of the shielded pump
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Hammettik’s pumps. The material is cyclohexane; half an hour after the pump was stopped and restarted, the pump current remained overloaded (exceeding 400A, while the normal value is around 200A), and there was almost no pressure at the outlet. The same problem persists even after importing and restarting. What is the reason?
Well, I can now reply. There are two reasons for the high starting current: 1. The density or viscosity of the medium changes significantly with temperature; when the pump stops operating, the temperature drops and the density or viscosity increases, making it difficult to start the pump. It doesn’t seem to be the case based on your description. 2. If the flow rate is too high, the pump’s motor will not have its start-up power taken into account for opening the valve, unless otherwise specified; therefore, please check whether the outlet valve is closed when starting the pump. It should be fully closed or slightly open at the time of startup, and then gradually opened after that. Additionally, a minimum return line is typically designed in the outlet pipeline of shielded pumps; if this line is too large, it can also cause overload. Therefore, it should be closed or kept slightly open during startup, then gradually opened fully after startup, after which the return valve is closed and the outlet valve is opened, until operation stabilizes and reaches normal conditions.
Almost no pressure on exports? If the current is high, there should be pressure, right? Isn’t the outlet closed?
The rotor or impeller is stuck – disassemble the machine to check the wear-prone components; there must be some mechanical damage to the rotating parts. As for the causes: 1) a problem with the pump itself; 2) a problem with the system. Your description isn’t sufficient, so it’s still unclear at this point