Can't the water pump start? Insufficient flow? Can't suck water? Vibration, noise, motor failure... What should I do?

The water pump cannot be started

Common causes: the packing is too tight or the impeller and pump body are blocked by sundries; The pump shaft, bearing and leakage reducing ring are rusted; Serious bending of pump shaft, etc.

Elimination method: loosen the filler and dredge the water diversion tank; Disassemble the pump body, remove sundries and rust; Remove the pump shaft and correct or replace it with a new one.

Insufficient flow

Causes: most of them are air leakage of suction pipe and bottom valve; The water inlet is blocked; Insufficient water inlet depth of bottom valve; The speed of water pump is too low; Excessive wear of sealing ring or impeller; The water absorption height exceeds the standard, etc.  

Troubleshooting: check the suction pipe and bottom valve to block the leaking air source; Clean the silt or blockage at the water inlet; The water inlet depth of the bottom valve must be greater than 1.5 times the diameter of the water inlet pipe, and the water inlet depth of the bottom valve shall be increased; Check the power supply voltage, increase the water pump speed, and replace the sealing ring or impeller; Lower the installation position of the water pump or replace the high lift water pump.  

Can't absorb water

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

Troubleshooting:

First raise the water pressure, then fill the pump body with water, and then start the machine. At the same time, check whether the check valve is tight and whether the pipeline and joint have air leakage. If air leakage is found, apply lubricating oil or blending paint on the joint after disassembly, and tighten the screws.

Check the oil seal ring of the water pump shaft. If it is seriously worn, replace it with a new one.

Water leakage or air leakage of pipeline. The nut may not be tightened during installation. If the leakage is not serious, cement can be applied at the place of air leakage or water leakage, or cement slurry mixed with asphalt oil. For temporary repairs, apply some wet mud or soft soap. If there is water leakage at the joint, the nut can be tightened with a wrench. If the water leakage is serious, it must be disassembled and reinstalled to replace the cracked pipe; Reduce the head and press the nozzle of the water pump into the water for 0.5m.

The water pump does not discharge water

Cause: the pump body and suction pipe are not filled with water; The dynamic water level is lower than the water pump filter pipe; Rupture of suction pipe, etc.  

Troubleshooting: eliminate the fault of bottom valve and fill the water diversion; Lower the installation position of the water pump so that the filter pipe is below the dynamic water level, or wait for the dynamic water level to rise, and then pump water from the filter pipe; Repair or replace the suction pipe.

The pump body vibrates violently or generates noise

Causes: the water pump is not installed firmly or the water pump is installed too high; The motor ball bearing is damaged; The main shaft of the water pump is bent or not concentric or parallel with the main shaft of the motor.  

Treatment method: install the water pump stably or reduce the installation height of the water pump; Replace the motor ball bearing; Correct the bent water pump spindle or adjust the relative position between the water pump and the motor.  

Excessive power consumption

Cause: the speed of water pump is too high; The water pump spindle is bent or the water pump spindle is not concentric or parallel with the motor spindle; Improper pump lift; The water pump sucks sediment or has blockage; Damage of motor ball bearing, etc.  

Treatment method: check the circuit voltage and reduce the water pump speed; Correct the main shaft of the water pump or adjust the relative position between the water pump and the motor; Select water pump with appropriate head; Clean up sediment or blockage; Replace the ball bearing of the motor.  

Drive shaft or motor bearing overheating

Causes: lack of lubricating oil or bearing rupture, etc.  

Treatment method: add lubricating oil or replace the bearing.   These are the common reasons for the "disease" of the water pump, not all of them. In practice, when dealing with the fault, according to the specific problems and actual analysis, we should follow the principle of "outside first and then inside", and do not operate blindly.

If there is something wrong with the motor of the water pump, what should I do?

Motor overload during water pump operation

General motors have a rated operating power, which is called rated power, and the unit is watt (W) or kilowatt (kw). If, under certain circumstances, the actual operating power of the motor exceeds the supporting rated power of the water pump, this situation is called motor overload. Motor overload has the following forms:

Excessive heat generation of motor;

The motor speed drops, or even drops to zero, which shows that the motor does not rotate;

The motor has a low buzzing sound accompanied by large vibration;

When the motor load changes dramatically, the motor speed will fluctuate from high to low.

Causes and Solutions

The three-phase motor is out of phase when the water pump is running

When the three-phase motor is running, the driving power supply must be provided by three cables to achieve three-phase balanced operation; If the power supply is provided by two power lines, it can also operate, but the prolonged operation time will cause the motor to burn out due to lack of phase. Method for judging motor phase loss:

Use a universal meter to measure the voltage of three power lines and check whether there is no voltage drop in one phase;

Check whether the copper wires in the three power lines are blackened, and whether the copper wires of one power line are not blackened and remain as they are;

Open the motor cavity. Generally, two phases of three-phase motor will be burned, and the other phase will remain as it is.

Causes and Solutions

Sudden power trip of water pump motor

If the matched power protector is consistent with the water pump motor, the protector will not trip under normal conditions. The main causes of protector tripping are:

Overload of water pump motor;

The temperature rise of water pump motor is too high;

The running current of water pump motor is too large;

The power supply voltage of the water pump is too high.

Causes and Solutions

The water pump motor is flooded

Under normal circumstances, water is not allowed to enter the pump motor (except for water immersion pump). There are several situations of water inflow into the motor:

1. Water ingress due to damage of waterproof cable;

2. The power line wiring of water pump motor is not sealed well, and water enters the water;

3. The sealing structure at the inlet of water pump motor is damaged and water enters;

4. The mechanical seal of the water pump is damaged and water enters;

5. The O-ring of the water pump is damaged and water enters;

6. The bolts at the seal are not tightened, resulting in water ingress into the motor;

7. Water pump parts are damaged and water seepage.

Causes and Solutions

Leakage of water pump motor

In general, the water pump motor will not leak electricity, but the motor will leak electricity under the following conditions:

1. Damage and leakage of waterproof cable;

2. The wiring of the power line of the water pump motor is not well sealed, and there is leakage;

3. Water inlet leakage of water pump motor;

4. Leakage of water pump motor after burning;

5. Low insulation resistance leads to leakage.

In order to ensure the personal and property safety of the water pump in the case of motor leakage, the grounding of the water pump must be installed correctly, and the leakage switch is best installed at the same time.

Causes and Solutions

The water pump motor cannot be started

The pump motor does not start (does not rotate or the speed is too low) generally due to the following reasons:

1. Leakage of water pump;

2. The supporting power supply voltage is too low;

3. The water pump impeller is stuck due to foreign matters;

4. The bearing is damaged and stuck;

5. Motor overload operation (overload);

6. Reverse connection of three-phase water pump and three-phase power supply;

7. Phase loss of three-phase motor;

8. The motor sweeps the chamber;

9. The capacitor is damaged, inversely connected and the capacity is too small.

Causes and Solutions