1. [the water pump does not run during startup]

Cause: the packing is too tight or the impeller and pump body are blocked by sundries; Pump shaft, bearing and leakage ring rusted; The pump shaft is severely bent.

Troubleshooting: loosen the packing and dredge the water diversion tank: disassemble the pump body to remove sundries or rust; Correct the bent shaft or replace the pump shaft with a new one.

2. [water pump does not discharge water after startup]

Cause: there is air in the pump or air accumulation in the water inlet pipe; The bottom valve is not closed tightly, the filling water is insufficient, and the packing of the vacuum pump leaks seriously; The gate valve or flap door is not tightly closed.

Troubleshooting: remove the sundries, replace the damaged rubber pad, and change the direction of the valve plate; Compress or replace with new packing, and close gate valve or flap valve; Increase the amount of water filling until there are no bubbles at the vent plug; Replace the cracked water pipe; Reduce the head and press the nozzle of the water pump into the water for 0.5m.

3. [insufficient flow]

Cause: the actual lift of the water pump exceeds the allowable lift; The rotating speed is not matched or the belt slips and the rotating speed is low; Axial flow pump blade installation angle is too small; The suction lift is too high; Local blockage or impeller defect of bottom valve, pipeline and impeller; The water outlet pipe leaks seriously.

Troubleshooting: reduce the lift, restore the rated speed, remove the belt dirt and adjust the belt tightness; Adjust the blade angle and lower the installation position of the water pump; Tighten the gland and seal the water leakage of the water pump, compress the packing or replace the packing; Remove the blockage and replace the impeller; Replace the leakage ring and plug the leakage.

4. 【 flow rate changes from large to small 】

Cause: the filter screen or bell mouth is gradually blocked by sundries; The dynamic water level decreases and the water inlet pipe is not submerged enough.

Troubleshooting: remove sundries and increase the water inlet depth of the bottom valve.

5. [water outlet interruption during operation]

No water or intermittent water, less water.

① If the motor is not started, eliminate the circuit fault;

② If the pipeline is blocked, remove the blockage;

③ Pipeline rupture, repair welding or replacement;

④ The water filter is blocked and the blockage is removed;

⑤ The suction port is above the water surface. If the discharge pump is still invalid, it is recommended to replace the pump;

⑥ Reverse the electric pump and change the phase sequence of the power line;

⑦ The pump casing sealing ring and impeller are damaged, replace them with new ones.

6. [the motor cannot be started, accompanied by buzzing]

① If one phase is open circuit, repair the line;

② Bearing holding shaft, repair or replace;

③ Foreign matters in the impeller are stuck with the pump body to remove foreign matters;

④ If the voltage is low, adjust the voltage.

7. [the current is too large, and the pointer of ammeter swings]

① Sweep the rotor cavity and replace the guide bearing;

② The relative rotation of shaft and bearing is not flexible, replace or repair the bearing;

③ Replace the thrust bearing or thrust disc because the thrust bearing is seriously worn and the blade rotates against the sealing ring;

④ The shaft is bent and the bearing is not concentric. Send it to the cramp factory for repair.

8. [insulation resistance of motor winding to ground is low]

If the motor winding and cable joint or cable are damaged, replace the winding and repair the joint or cable.

9. [severe vibration during unit operation]

① The motor rotor is unbalanced. Except that the bolts are loose and can be fastened, other faults shall be sent to the manufacturer for treatment;

② The impeller of water pump is unbalanced;

③ The motor or pump shaft is bent.

10. [loose connecting bolts]

Cause: the pipeline or water inlet is blocked by sundries; The packing is worn, loose and the water seal pipe is blocked; The impeller is damaged or loose; The dynamic water level drops sharply.

Troubleshooting: remove the blockage, replace the filler, dredge the water diversion pipe groove, and install the water seal correctly; Fasten or replace the impeller; Lower the installation position of the water pump, or start it after the water level rises.

11. [too much power consumption]

Cause: the rotating speed is too high; Bending of pump shaft; There are sundries around the blade; The lift is too high.

Troubleshooting: adjust the appropriate speed; Correct the pump shaft.

(source: mechanical expert network)