Common faults and solutions of sewage pump
There are many common faults in the installation and use of sewage pump. The following is a simple summary and solutions are attached for reference.
Fault 1. The blowdown 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.
Fault 2. The 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.
Fault 3. The flow 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.
Fault 4. 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.
Fault 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.
Fault 6. The motor cannot be started with buzzing sound
① If one phase is open circuit, repair the line;