Starting current issues of variable-frequency motors in double-suction pumps
Thread Content
Double-suction pump parameters: head of 20 meters, flow rate of 1950 cubic meters. Variable-frequency motor: 160KW, speed of 990 revolutions per minute. Axial deviation of the drive wheel: 13 threads. It was the first time the pump was started today; the starting frequency was 5HZ. At that time, the current displayed on the inverter ranged from 75 to 105A, with significant fluctuations, and the pump did not rotate at a steady speed. After the frequency is increased to 10 Hz, the current remains essentially stable at 45 A; even as it continues to rise, the current stays fairly stable. Is the aforementioned phenomenon caused by poor low-frequency performance of the motor, or by insufficient alignment accuracy of the pump’s coupling gears?
With no load, the water pumps operate with their outlet valves closed.
Incorrect alignment of the pump’s coupling gears, as well as issues with foreign objects affecting the pressure sensor’s signal feedback, can all have an impact.