Possible problems encountered when using water pumps

Unable to start

Firstly, the power supply situation should be checked: whether the connector connection is secure; Check if the switch contacts are tight; Whether the fuse is blown; Is the three-phase power supply lacking equality. If there is an open circuit, poor contact, blown fuse, or missing phase, the cause should be identified and promptly repaired. Secondly, check if it is a mechanical fault of the water pump itself. Common reasons include: too tight packing or blockage between the impeller and the pump body caused by debris; Rust on the pump shaft, bearings, and leakage reducing ring; Severe bending of the pump shaft, etc. Elimination method: Loosen the filling material and dredge the drainage channel; Disassemble the pump body to remove debris and rust; Remove the pump shaft for calibration or replace it with a new one.

Water pump heating

Reason: Bearing damage; The clearance between rolling bearings or bracket covers is too small; The pump shaft is bent or the two shafts are not concentric; The tape is too tight; Lack of oil or poor oil quality; The balance hole on the impeller is blocked, causing the impeller to lose balance and increasing the thrust to one side. Troubleshooting: Replace the bearing; Remove the rear cover and install a gasket between the bracket and the bearing seat; Investigate the pump shaft or adjust the concentricity of the two shafts; Adjust the tightness of the tape appropriately; Add clean butter, which accounts for about 60% of the clearance in the bearing; Remove any blockages from the balance hole.

Unable to absorb water

The reason is that there is air in the pump body or air accumulation in the inlet pipe, or the bottom valve is not tightly closed, the water supply is insufficient, the vacuum pump packing is severely leaking, and the gate valve or flap valve is not tightly closed. Solution: First increase the water pressure, 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 any air leakage in the pipeline and joints. If any 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. Pipeline leaks water or air. The nut may not be tightened tightly during installation. If the leakage is not severe, cement can be applied to the leaking area or cement slurry mixed with asphalt oil. Temporary repairs can be done with damp mud or soft soap. If there is water leakage at the joint, a wrench can be used to tighten the nut. If the leakage is severe, it must be reassembled and replaced with a cracked pipe; Reduce the head and press the nozzle of the water pump 0.5m underwater.

convulsion

There are several main reasons: the electric rotor is unbalanced; Poor coupling connection; Bearing wear and bending; Loose or cracked rotating parts; Reasons such as loose pipeline supports. Measures such as adjustment, repair, reinforcement, straightening, and replacement can be taken separately.

Motor overheating

There are four reasons. One reason is due to power supply: the voltage is too high or too low. Under specific loads, if the voltage variation range should be outside of+10% to -5% of the rated value, it will cause the motor to overheat; Asymmetric three-phase voltage of the power supply, with an imbalance of more than 5% between phases, can cause overheating of the winding; Experience has shown that over 85% of the burning of agricultural motors is caused by phase loss operation. Therefore, phase loss protection devices should be installed on the motors. Secondly, there are reasons for the water pump: the selection of power is not matched, the small horse pulls the big car, and the electric motor is overloaded for a long time, causing the temperature of the electric motor to be too high; Motors that start too frequently and are rated for short-term or intermittent duty operate continuously. The number of starts should be limited, thermal protection should be selected correctly, and used according to the rated values specified on the motor. The third reason is the motor body: incorrect connection, mistakenly connecting the △ shape to the Y shape, causing the temperature of the motor to rapidly increase; The stator winding has phase to phase short circuit, turn to turn short circuit, or local grounding. In mild cases, the motor may overheat locally, and in severe cases, the insulation may be burnt out; The squirrel cage rotor has broken bars or defects, and the motor runs for 1 to 2 hours, resulting in a rapid increase in iron core temperature; If there is a malfunction in the ventilation system, it is necessary to check whether the fan is damaged, whether the rotation direction is correct, and whether the ventilation duct is blocked; The wear of bearings and the eccentric cleaning of the rotor cause a metal impact sound when the stator and rotor iron cores collide, causing the temperature of the iron core to rapidly rise. In severe cases, the motor may smoke and even the coil may be burned. The fourth reason is due to the working environment: the motor winding is affected by moisture, dust, oil stains, etc., which adhere to the winding, resulting in a decrease in 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 ℃, the high inlet air temperature can cause the temperature of the motor to be too high. Efforts should be made to improve its working environment. For example, setting up a shed to shade the sun. Attention: If a malfunction occurs due to electrical reasons, it should be repaired by an electrician who has obtained a professional qualification certificate. People with limited knowledge should not blindly repair to prevent personal injury accidents from occurring

Source of the article: excerpts from Baidu Baike