With two pumps running and one standby, if one is stopped, will it cause the current of the other one to be too high?
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This post was last edited by kaminocmyhc on 2010-9-17 08:54 For two pumps running at the same time, if the inlet filter of one pump is clogged and you need to stop and clean the filter, just follow the step of stopping the pump and close its outlet to stop it. Will it cause the current of the other pump to be too high? Why? Centrifugal pump, and the flow rate is relatively large, about 300 cubic meters per hour.
Personally, I feel that if two running pumps are stopped and one is stopped, if the pressure in the pipeline remains unchanged, the current flow should not change. On the contrary, if the pressure changes, the pump speed will also change, causing the current to also change.
This post was last edited by kaminocmyhc on 2010-9-17 08:54. It is a centrifugal pump, which will have an impact on another pump and increase its current.
Just in case, it is best to turn down the outlet valve of the pump that is running
This post was last edited by kaminocmyhc on 2010-9-17 08:57 7# Zhang Liming In this way, the current must be increased, because the flow rate of the two pumps must be doubled, so the flow rate of one pump is not enough, and the system pressure will decrease. If the outlet pressure of the centrifugal pump decreases, the flow rate will increase. When the flow rate increases, the current of the motor will naturally increase.
This post was last edited by kaminocmyhc on 2010-9-17 08:58. There are two methods: one. You can know it through theoretical calculation and just look at the flow rate. 2. You should communicate well with the process. If the current really increases, pay attention to the opening of the outlet valve of the operating pump.
Generally there will be an impact. Normally, operate as follows: 1. Two people go to the scene, one person slowly closes the outlet valve of the deactivated pump, the other person observes the current of the pump in use, and the internal operator pays attention to the changes in flow rate. 2. If you observe that the current in use is extremely high, you can appropriately close the outlet valve of the pump in use to control the flow. If the pump in use does not exceed the current, there is no need to close the outlet valve. 3. After confirming that the outlet valve of the deactivated pump is closed, the pump can be stopped. 4. Pay attention to adjusting the opening of the control valve and check whether the pump in use exceeds the current. A notification is issued to inform the team of the flow control range.
It is recommended that the motor be changed to a larger size because the existing motor is too sizing. It is recommended that the outlet valve be closed slowly during current operation. If the flow is controlled by the control valve, the valve opening changes. If the outlet valve closes too quickly, the flow rate will decrease and change greatly, the control valve opening will become larger, and the pump needs to supplement the flow during startup, and the current will increase.
For centrifugal pumps, it will definitely increase. If two people carry something, now one person can carry it, and the output will of course be greater. Whether it is too high depends on the situation. Supports the 14th floor operation method. Just one problem ； How can I get two pumps and one standby so that I can only operate one pump? . . . .
This post was last posted by kaminocmyhc on 2010-9-17 09:02 Editor, thank you for your attention to my problem. The two pumps continued to work last night. The inlet filter of one of them was blocked and the inlet pressure dropped (0.32 MPa during normal operation, dropped to below 0.2 MPa). The outlet valve of the other pump was not closed and was directly closed. Blocked the outlet valve of the filter pump, then stopped the pump, and then quickly asked the electrician about the current of the other pump. The electrician said that the current of that pump exceeded the rated current, reaching 300A (when the two pumps are running at the same time, the current is about 240A, and the rated current is 287.8A). The operation method provided on the 9th floor is very feasible. Worth recommending!
If there are two centrifugal pumps in the same system, if one is stopped to deal with the problem, the current of the other will definitely increase, because the system pressure will decrease after stopping one, but the relative flow rate relative to the other pump will increase.