The pump outlet valve opens only a little bit yet the pressure becomes very high~ What’s the reason for the trip if it is opened further?
Thread Content
Tripping occurs immediately upon starting the pump when the minimum flow valve is fully open～
We have a similar problem that hasn’t been resolved for many years as well – it’s an alkali pump. Several areas I had suspected: clogged pump inlet filter, sealing issues, motor being too small, and the medium being transported having too high a density. For over a decade now, whenever we start the pump, we ask an electrician to come and turn off the power in order to open the outlet valve; everything works fine when they do that.
Indeed, it’s today that we’ll call an electrician to turn off the pump by cutting off the power supply; the filter issue should be solvable first of all because the medium is very clean, and secondly, if the inlet filter is clogged, the output flow won’t increase. I suspect the motor isn’t compatible with the pump – the motor is too small. But the export volume is within the designed range~ It’s tricky
The required power can be calculated based on factors such as the medium density and rated flow rate. The motor was supplied by the pump manufacturer, so there should be no problems
This pump is being reused; the original medium was C7+, and now it’s C6 – it’s become lighter
The motor power selected by the pump manufacturer based on the flow curve. When starting the pump, it is sufficient to meet the flow rate requirement, so there is no need to open it fully. The motor tripped due to overload when running at full capacity.
The opening degree of the key outlet valve is too small; it trips due to excessive flow after just two or three turns. The quantity meets the requirements; could it be that the diameter of the outlet pipe is too large? It’s awkward to use. There’s another shielded pump with the same problem
Open with a gap? If it starts with a gap, it indicates that the current suddenly increases by ten times or even several times, resulting in severe overloading of the motor. This usually occurs when there are abnormalities such as the pump blades getting stuck, the bearings getting stuck, or short circuits in the motor coils
At a rated current of 55, the instantaneous value reaches 76 under the condition of full opening and minimum flow rate; it doesn’t exceed this level significantly
The fundamental reason is still the low pressure after the pump, which results in a high flow rate of the pump. You might try turning off the minimum flow line, closing all the outlet valves; one person should monitor the ammeter while another operates the valve behind the pump, until the flow rate meets the required level. Then, slowly open the minimum flow line until the current meets the required level. Finally, the valve opening of the minimum flow line should not be changed.
It’s probably because the impeller angle is too large. The outlet was cast by the pump factory, so there should be no problem.