Common faults and maintenance of self-priming pumps

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Motor section: 1. No response after power is connected. Most are caused by short circuits in the power plug, power leads, and motor windings. 2. Difficult to start or fails to start, accompanied by a \"buzzing\" sound. During maintenance, a small bamboo piece can be used to quickly move the fan blades in the direction of rotation; if the motor starts spinning rapidly, it indicates that the starting capacitor or the starting winding is damaged, and it is necessary to replace it with a capacitor of the same capacity or repair the starting winding ； If the motor gets stuck, it is usually due to mechanical faults in the motor and pump head, such as damaged bearings or a stuck impeller. 3. The motor can operate, but its speed is low; moreover, the casing overheats and there is a burnt smell. In most cases, it is caused by a short circuit in the motor windings; the motor should be disassembled, and depending on the extent of the damage, repairs such as welding, using jumpers, isolation, or rewinding should be carried out. 4. High noise and vibration levels during operation. In most cases, it is due to damaged bearings or an improper fit between the bearings and the housing; the motor needs to be disassembled for inspection. If the bearings are damaged, they need to be replaced ； If the bearing runs on the outer circumference, the mating surface of the pump casing can be treated with embossing ； If the bearing is wearing on its inner surface, the worn area of the motor shaft can be treated with chiseling; in cases of severe wear, it can be repaired by first performing surfacing and then turning. Pump head section: 1. The motor is operating normally, but the water output is low or there is no water output at all. In such a situation, the seal of the water pump should be checked first. To do this, unplug the power cord first, cover the water inlet with your hand, fill the pump with water, then hold the outlet with your mouth and blow hard into it to see if there is any leakage from the pump head; the area where leakage occurs is where the seal is damaged. Common faulty parts include the water inlet gasket, the water outlet gasket, and the impeller cover gasket, which should be replaced during maintenance. If there is no water filling phenomenon, it is usually due to damaged impellers, erosion of the water separation partition between the suction chamber and the discharge chamber, wear down of the partition at the pump head, or an increased gap between the impeller and the pump casing; in such cases, the impeller and pump casing should be replaced. When replacing the foot wheel, care should be taken to thoroughly remove any remaining copper blades inside the pump, to prevent further damage to the new impeller. 2. The casing is charged. In most cases, it is caused by a damaged water seal, with water seeping into the motor through the motor shaft and thereby deteriorating the motor’s insulation properties. This can be repaired by replacing the water seal or drying the motor. It should be noted that since water pumps are in constant contact with water and operate outdoors, they are highly susceptible to moisture, which can lead to a deterioration of their insulation properties. To ensure personal safety, electric self-priming pumps must be properly grounded.