Seeking advice on centrifugal pump overload issues, thank you
Thread Content
The centrifugal pump model is ISG50-250B, with a flow rate of 14 m3/h and a head of 58 meters. The motor connected to it has a power rating of 7.5 kW. The pipeline layout is as shown in the diagram; the pressure at the inlet is 0.18 Mpa. This pressure then goes to the seal systems of the three units, where the pressure must be no less than 0.6 Mpa. Currently, only one of the three units is in operation, so the DN16 pipeline remains open throughout. The motor tends to overheat frequently these days. Could anyone please explain the reasons for this? Thank you!
The DN16 diameter of the outlet is too small; the flow rate is too low. It’s likely a load issue caused by a fault in the pump itself
Reasons for motor overload: 1. Excessive flow rate, heavy load； 2. The motor voltage is too high or too low ； 3. Prolonged exposure of the motor to moisture or corrosive gases can lead to a decrease in insulation resistance ； 4. Lack of oil in the motor bearings, dry friction, or misalignment of the rotor machinery cause the motor current to exceed the rated value ； 5. Malfunctions in the mechanical transmission part, etc. Based on flow rate and head, your effective power is around 2.2 KW; using a 7.5 KW motor is excessive, and overcurrent will not occur due to the flow rate (unless the flow rate is inaccurate). You guys should check the other aspects by yourselves.
Having variable frequency is more practical than anything else
Thank you all for your suggestions; the pressure gauge at the outlet shows five kilograms
Similar to 2l, it’s probably not motor overload; with such a large margin, it might be that the flow rate is below the pump’s minimum flow rate.
What are the characteristics of overload in your motors? What is the current?
The motor overheats severely, causing the thermal relay to trip; the current measured is around 17A
Is the motor’s rated current around 13.5?