What are the common faults and solutions for diesel water pumps?
If the diesel water pump is not operated in the correct way during use, various faults may occur. At this time, you must conduct a comprehensive inspection on it first. Different problem handling methods are also different. Here are some solutions to common failures in water pump maintenance.
- Cannot start
First, check the power supply: whether the connector is firmly connected; whether the switch is in close contact; whether the fuse is blown; whether the three-phase power supply is equal. If there is open circuit, poor contact, blown fuse, or missing phase, the cause should be found out and repaired in time. Secondly, check whether it is a mechanical failure of the pump itself. Common reasons include: packing is too tight or the impeller and pump body are jammed and blocked by debris; the pump shaft, bearing, and leakage ring are rusted; the pump shaft is severely bent, etc. Elimination methods: loosen the packing, dredge the water diversion tank; disassemble the pump body to remove debris and rust; remove the pump shaft for correction or replace with a new pump shaft.
- The water pump heats up
Reason: bearing damage; rolling bearing or bracket cover clearance is too small; pump shaft is bent or two shafts are not concentric; tape is too tight; lack of oil or oil quality is not good; the balance hole on the impeller is blocked, the impeller loses balance, increasing the direction Thrust on one side. Remedy: replace the bearing; remove the back cover, install a gasket between the bracket and the bearing seat; investigate the pump shaft or adjust the concentricity of the two shafts; appropriately loosen the tape tightness; add clean butter, and the butter occupies the bearing About 60% of the inner gap; clear the blockage in the balance hole.
- Insufficient flow
This is because the power speed is not matched or the belt slips, which makes the speed low; the blade installation angle of the axial flow pump is too small; the lift is insufficient, the pipeline is too long or the pipeline has a right angle bend; the suction lift is too high; the bottom valve, pipeline and Partial blockage of the impeller or impeller defect; serious water leakage in the outlet pipe. Remedy: restore the rated speed, remove the belt grease, adjust the belt tightness; adjust the blade angle, reduce the installation position of the water pump, shorten the pipeline or change the curvature of the pipeline; seal the leak of the water pump, compact the packing; remove the blockage Replace the impeller; replace the leakage reduction ring to block the leakage.
- Can’t absorb water
The reason is that there is air in the pump body of the diesel water pump or gas accumulation in the water inlet pipe, or the bottom valve is not closed tightly. Remedy: First press the water up, then fill the pump body with water, and then turn it on. At the same time, check whether the check valve is tight and whether there is air leakage in the pipeline and joints. If air leakage is found, apply lubricating oil or mixed paint to the joint after disassembly, and tighten the screws. Check the oil seal ring of the water pump shaft and replace it with a new one if it is severely worn. Water or air leakage in the pipeline. The nut may not be tightened tightly during installation. If the leakage is not serious, apply cement or cement slurry mixed with asphalt oil on the leaking or leaking place. Temporary repairs can be coated with wet mud or soft soap. If there is water leakage at the joint, you can use a wrench to tighten the nut. If the water leakage is serious, you must re-disassemble and replace the cracked pipe; reduce the head and press the nozzle of the pump into the water 0.5m.
- Severe vibration
The main reasons are as follows: the electric rotor is unbalanced; the coupling is not well connected; the bearing is worn and bent; the parts of the rotating part are loose or broken; the pipeline support is not strong. Measures such as adjustment, repair, reinforcement, straightening, and replacement can be taken separately.
- The supporting power motor is overheated
The reasons are: one is the power supply: the voltage is too high or low. Under a certain load, if the voltage fluctuation range should be outside the rated value of +10% to -5%, the motor will overheat; the three-phase voltage of the power supply is not Symmetrical, the unbalance of the three-phase voltage of the power supply exceeds 5%, which will cause the winding to overheat; the lack of phase operation, experience shows that more than 85% of the agricultural motor is burned due to the lack of phase operation, and the motor should be equipped with a lack of phase protection device. The second is the reason for the water pump: the power is not matched, the small horse-drawn cart, the motor is overloaded for a long time, and the motor temperature is too high; the motor is started too frequently, and the rated short-time or intermittent working system continues to work. The number of starts should be limited, thermal protection should be selected correctly, and used according to the calibrated rating on the motor. The third is the reason of the motor itself: the wrong connection method, the wrong connection of the △ shape into the Y shape, makes the temperature of the motor rise rapidly; the stator winding has inter-phase short-circuit, inter-turn short-circuit or partial grounding, and the motor is locally overheated in mild cases, and insulated in severe cases. Burnout; broken or defective squirrel cage rotor, the motor runs for 1 to 2 hours, the iron core temperature rises rapidly; if the ventilation system fails, check whether the fan is damaged, the direction of rotation is correct, and whether the ventilation holes are blocked; the bearing is worn, the rotor Eccentric sweeping makes the stator and rotor iron cores rub against each other and make a metal impact sound. The temperature of the iron core rises rapidly. In severe cases, the motor emits smoke or even the coil burns. The fourth reason is the working environment: the motor windings are damp, dust, oil, etc. attached to the windings, resulting in reduced insulation. The insulation resistance of the motor should be measured and cleaned and dried; the ambient temperature is too high. When the ambient temperature exceeds 35°C, the intake air temperature will be high, which will cause the temperature of the motor to be too high, so try to improve its working environment. Such as scaffolding and shading.
Note: If a malfunction occurs due to electrical reasons, an electrician who has obtained a professional qualification certificate should be asked to repair it. People with a little knowledge should not repair it blindly to prevent personal injury accidents.
The above situations are the common causes of water pump failures, not all of them. In practice, to deal with failures, due to actual analysis, the principle of first outside and inside should be followed, and no blind operation should be avoided.