In recent years, the number of submersible electric pumps used in rural areas has increased. In order to reduce the occurrence of accidents in use, it is necessary to strengthen the usual maintenance.
↑Click on the pic above to get 【submersible electric pump】 specs,price etc.↑
1. Always check the seals for various seals of the submersible electric pump, such as refueling screws, rubber sealing rings, the sealing box of the oil-immersed electric pump, etc. Tighten it in time. If the seal is not strong, replace it with a new one in time to ensure safe use.
2. Change the oil regularly After the oil-immersed electric pump works for 500 hours, the oil in the sealed chamber should be replaced once. The oil in the motor cavity should also be replaced once a year, and the replacement should be clean No. 5 or No. 10 oil. For wet electric pumps, the lithium-based grease needs to be replaced every 2000 hours of operation.
3. Prevent rust When the submersible pump is not in use, it should be wiped clean and placed in a ventilated and dry place. If the surface of the electric pump is damaged and peeled off, the rust should be removed in time, and anti-rust paint should be applied to protect it.
4. Do a good job of comprehensive maintenance. Generally, a comprehensive maintenance is required every two years for submersible electric pumps. For worn parts and parts with poor sealing performance, those that can be repaired and those that cannot be repaired must be replaced, and cannot be used reluctantly. to avoid serious consequences.
The maintenance is mainly to ensure the reliable operation of the submersible pump and prolong its service life. It is necessary to conduct comprehensive maintenance on the submersible pump and its control system on a regular basis. At least one comprehensive preventive maintenance is done every year. There is no abnormality, whether the starting device works normally, whether the over-temperature water leakage alarms, whether the multiple protections established by the meter control operate frequently, whether the main cable and control cable are aging and cracking, whether the main contactor is sticky, oxidized or burr, whether the thermal relay is set Correct, whether the winding insulation layer has signs of aging, whether the insulation resistance to ground is too low, whether the three-phase winding resistance is balanced, whether there are sweeps or scratches on the stator and rotor, whether the liquid level gauge of the control system is accurate, and whether the upper and lower limit outputs are normal. Reliability, whether the floating ball action is reliable, whether the temperature detection element is aging and malfunctioning, whether the oil is emulsified, whether the mechanical seal is in good condition, whether the bearing is worn, whether the impeller is worn or cavitated, whether the shaft is rusted, deformed or worn, whether the inside and outside of the motor Check whether the fastening screws are loose, whether there are sundries in the cooling jacket and circulating water pipe, whether there is sediment deposition or blockage in the pump Ll and its surroundings.
In the process of preventive maintenance and submersible pump operation, the over-temperature alarm should be correctly distinguished, whether the alarm is a real over-temperature or a malfunction due to the aging of the components. If the components are aging, you only need to connect their signals to the alarm signal, and do not let them directly participate in the control, so as to reduce the frequent starting of the submersible pump.
Common Problems in Maintenance Work The submersible electric pump is immersed in water for a long time, resulting in the aging and cracking of the outer skin of the main cable, and the water directly enters the submersible electric pump through the crack along the inside of the cable. Cracks, after cleaning and descaling the surface of the cable, you can use waterproof tape to wrap it for waterproof treatment, but pay attention to check the insulation with a shaker after soaking for a few hours, and it can be put into operation after meeting the requirements. Replace mains cables with substandard insulation or no repair value. Because the main cable is a special cable with watertight joints, the replacement price is more expensive, so the method of processing and bonding can be used to save costs. During maintenance, the oil emulsified due to water intake needs to be replaced, but in order to save costs, the emulsified oil can be regenerated with a special oil filter device and then recycled. In the maintenance, sometimes the pump shaft is rusted and the bearing cannot be taken out. At this time, the bearing can be submerged in the oil and heated to 70-80%, and then pulled out with a puller. Do not directly use the puller to hard pull or cut with gas to avoid Damage to the bearing, resulting in deformation of the main shaft. If the pump shaft is worn, bent and deformed, it can be repaired or corrected by spraying after rust removal.
After long-term use of the submersible electric pump, the impeller will have holes due to wear and cavitation, or the impeller will completely penetrate, which will seriously affect the efficiency of the pump and the balance of the impeller. If it runs for a long time, the mechanical seal and bearings will be further damaged. Replace or repair in time. In order to save cost, Belzona 1311 or other repairing materials and cast iron powder can be used for repairs that only have cavities or local wear but the impeller has not completely penetrated, but in practice, attention should be paid to the smooth surface of the repaired surface. and the overall curve of the impeller, and do a dynamic balance test on the impeller to ensure that the pump rotates smoothly during operation. Generally, the repaired impeller can continue to run for 1 to 2 years.
After replacing the bearing and mechanical seal of the submersible pump, attention should be paid to the lowering of the rotor and the pump shaft during the assembly process, so as not to damage the stator winding and cause insulation damage or copper wire breakage. If a few are damaged, cover them with insulating sleeves and use low melting point solder (a similar situation has occurred in our factory, the melting point of the solder used is l20°C. Before welding, pay attention to wrapping wet cloth strips at both ends of the copper wires to be welded. , so as not to damage the insulation of other parts due to the high temperature during welding) After welding, after the insulating paint is applied and dried, the insulating sleeve is moved back to the welding place and covered, and then the repaired windings are separated from each other with insulating paper or insulating cloth to strengthen Insulation, and then coated with insulating paint and dried, check the insulation with a shaker, and proceed to the next step of installation after meeting the requirements. In addition, pay attention to the tightening screws between the lower end of the rotor and the oil chamber to prevent the stator coil from being damaged after the screw is loosened with the rotation of the rotor. During installation after maintenance, sealant should be applied to each connection sealing surface of the submersible pump to strengthen the seal and prevent water from entering. After the submersible pump is repaired, it should be fully immersed in the pool or water tank, and the water seal test should be carried out with 0.2MPa compressed air for 20 minutes. After checking that there is no air leakage in all parts of the submersible pump, it can be transported to the site for safety.