In the process of using centrifugal pump, there are many problems and failures, one of the most common faults is high current.
Here are some possible reasons.
In the process medium, if its density and viscosity exceed the specified index, it will likely lead to excessive current of centrifugal pump. Therefore, the material components need to be inspected, adjust the viscosity and relative density and design value to the specified range to ensure the smooth operation of the pump.
When the pump starts up, if the outlet valve is fully open and the resistance in the outlet pipeline is too small, it can also cause the excessive phenomenon of centrifugal pump current. So close the exit valve and slowly open the outlet valve after the pump starts; In addition, the imbalance of the pipe can also cause the phenomenon.
The high current of centrifugal pump has a great relationship with pump assembly, what's more, there is friction in the moving part. If it is caused by a bad pump assembly, then the pump needs to be reassembled. If it is caused by friction, the first need to check and adjust is the coordination clearance, bearing clearance, mechanical seal positioning and so on. It is worth noting that adjustments should be made strictly according to design requirements.
The cause of high centrifugal pump current may be the electrical fault, at this point, the setting value and voltage of the breaker heater should be checked. The three-phase current error should be less than 3 % and in the equilibrium state.
There are other reasons, such as the improper assembly or excessive space in the motor after the repair. The winding number of the stator winding is not enough or the y-type connection is mistakenly connected with delta connection.