2, listen to the sound of the transformer operation, in addition to the normal and uniform sound of the Weng, there is no abnormal sound such as burst. 3. Check whether the high and low voltage insulation bushings of the transformer are clean, with or without cracks and discharge marks. If there is dirt, wipe off with gasoline or alcohol after power failure. 4. Check whether there is leakage at each seal, and whether the oil level is normal or not. 5. Monitor the operating temperature of the transformer. The oil surface temperature rise during operation (temperature rise = upper oil temperature - ambient temperature) generally cannot exceed 45 °C. 6. Check whether the oil color in the oil level gauge of the oil conservator is transparent and take samples for inspection according to the specified inspection period. 7. Check if the fuel tank is well grounded, and whether the grounding wire is rusted or not. 8. Insist whether the glass container of the moisture absorber is damaged, observe the change of the color of the desiccant such as silica gel, and determine whether it has been damaged by moisture. (2) Maintenance period and content of the transformer 1, the transformer does not disintegrate minor repair Minor repair period: The capacity is below 1800KVA, and the voltage is less than 10KV and the following is minor repair every 1-2 years. Minor repair content: (1) Clean and inspect the transformer casing, outlet bushing and lead wire connector. 2 Release the dirt and water in the oil conservator, refuel if necessary, and check the oil gauge. 3 Check the drain valve and gasket. 4 Measure the insulation resistance of the coil. 5 Measure the grounding resistance. 2, the disassembly of the transformer overhaul l Overhaul period: Overhaul every 5-10 years. (3) Main items and contents of inspection of low-voltage power distribution equipment 1. Check the appearance of the busbars and connectors, and judge whether the temperature exceeds the allowable value by changing the color of the color change paint. 2. Whether the insulated porcelain bottle is clean, with or without cracks and discharge marks. 3. Whether there are other abnormalities in the cable terminal joints. 4. Whether the work of the instrument, comprehensive protection device and signal indicator of the secondary system is normal. 5. Whether the connection between the grounding of the equipment casing and the zeroing device is loose or broken. (4) Maintenance and repair cycle and content of low-voltage power distribution equipment 1. Maintenance period: at least once every six months. 2, maintenance content 1 Clean and remove dust, check the outer casing of low-voltage electrical equipment such as knife switch , circuit breaker , air switch, fuse, contactor, relay, main electric appliance (button, transfer switch , travel switch, etc.) for damage and insulation aging. 2 Check the above-mentioned low-voltage electrical equipment dynamic and static contact wear, test contact pressure and over-stroke, clean the particles generated after the metal surface of the contact is melted to ensure a good contact area. Replace the contacts when the contacts wear until their actual overtravel is only half of the original. 1 Check the dust and metal particles on the arc-extinguishing chamber wall and grid of the low-voltage electrical equipment (circuit breaker, air switch, contactor, etc.) with arc extinguishing device. 2 The operating mechanism is filled with lubricating oil at a certain time (2000-20000 times). Second, the motor inspection and maintenance 1. Inspection before starting the motor In order to ensure the safety of equipment and personal safety, the motor can be started normally. The following checks should be made before starting the motor for new installation or overhaul and long-term use: (1) Check if the voltage and frequency indicated on the motor nameplate are consistent with the power supply used, whether the connection is correct, and whether the capacity of the power supply matches the capacity of the motor and the starting method. (2) Is the wire size used appropriate, the wiring is correct, and the connection is firm. (3) Whether the capacity of the switch and contactor is appropriate, whether the contact is in good contact, and whether the protection current value of the fuse and the thermal relay matches the rated current of the motor. (4) The hand-cranked car should be uniform, stable and flexible, and the swaying should not exceed the specified value. Check if the bearing is short of oil, whether the oil quality meets the standard, and the required oil level should be reached when refueling. (5) Check the transmission device, the transmission belt should not be too tight or too loose, the connection should be reliable, no cracking; the screws and pins connected to the coupling should be complete and fastened. (6) Check the motor casing for cracks, whether the grounding is reliable, and the anchor screws and end cap bolts must not be loose; the safety measures such as the protective cover are intact. (7) Check the insulation resistance between the winding phase and the winding to ground. The motor with rated voltage below 500V is required to shake the insulation resistance value to not less than 0.5 megohm. If it is not, it should be dried. (8) For an irreversible motor, check that it is rotating in the correct direction. 2. Inspection after motor starting (1) Whether the starting current is normal. When the three-phase power is balanced, the deviation of any one of the three-phase currents from the average value of the three-phase should not exceed 10%. (2) Whether there is abnormal noise and vibration, and there is no smell or smoke. (3) Whether the running current is normal, whether there is overload condition, and whether the motor temperature rise is normal. Check parts Check item Check content Inspection Method Bearing sound Whether there is any abnormality Detect with ear or listening stick (iron rod) temperature Not higher than the ambient temperature of 55 ° C Hand mold or installation thermometer vibration Size change Hand touch or use vibrating meter Come on Oil quantity and leakage Visual inspection or oil level gauge stator temperature Core, coil temperature Hand touch or use a stick thermometer load Voltage and current Read the voltmeter, ammeter reading and record on time Connecting part Belt tension Hand touch feeling, visually observe vibration during operation Coupling concentric Visual inspection of vibration Check parts Check item Check content Inspection Method Bearing Come on Lubricating oil has no fouling Sampling, visual inspection for discoloration, impurities grease Raise as required Bearing frame With or without movement Visual inspection Shaft insulation Measuring insulation resistance Shaking table to measure insulation resistance to ground stator Air gap Stator and rotor clearance Dimensional air gap Insulation resistance Stator coil, rotor coil Shaking table to measure insulation resistance to ground external Bolts, terminal blocks Visual inspection, hand touch or not loose Connecting part Belt tension Hand touch feeling, visually observe vibration during operation With or without damage Belt surface wear Coupling concentric Measured with a dial gauge Bolts, pins With or without loose wear 5, the annual inspection content (1) Disassemble the motor windings, ventilation slots, and terminal block. (2) Measure the winding insulation resistance and dry if necessary. (3) Check the unevenness and yaw of the collector ring and commutator, and adjust the brush grip and the distance between them. (4) Clean the bearing and lubrication system, replace the rolling bearing that exceeds the specified wear, and re-hang the tin for the more serious sliding bearing. (5) Check the grounding device and measure the grounding resistance. (6) Adjust the transmission to replace the worn belt. Third, motor bearing maintenance and lubrication 1, the inspection method of the bearing (1) Listening: Use a screwdriver or iron rod, one end is inserted on the bearing with the bearing, and the other end is used to hear any special noise. If there is intermittent sound, there may be debris in the bearing; if whistle is generated The sound of the sound indicates that the bearing lacks lubricating oil or the bearing is rubbed. (2) Temperature measurement: measured by mercury thermometer or alcohol thermometer. The measured surface temperature plus 10 °C is about the internal temperature of the bearing; it can also be checked by hand touch. If the hand can be in close contact for a long time, the temperature should be Below 60 ° C. The normal operating temperature of the bearing is not higher than the ambient temperature by 55 ° C, and its temperature does not exceed 95 ° C. Working at too high a temperature will reduce its service life or even burn out. 2, bearing lubrication (1) Addition period of lubricating grease The lubricating grease of the bearing must be kept clean and sufficient. For the motor of the sliding bearing, the lubricating oil should be replaced after 1000 hours of operation; for the motor of the rolling bearing, the grease should be replaced after 2500-3000 hours of operation, and it should be added every 1000 hours or so. One grease. (2) Selection of rolling bearing grease In general, if the working temperature is lower than 120 °C, the ordinary lithium-based grease can be used. When the temperature is higher than 120 °C, the composite soap base or polyurea grease is used; in humid environment and water, the calcium-based grease is used. (3) Standard for adding rolling bearing grease The standard for adding the rolling bearing grease is determined by the rotation speed. When the rotation speed is below 1500 rpm, the amount is 2/3 of the bearing cavity, and the cylindrical bearing is added to the 2/3 of the lowermost roller; the rotation speed is 1500- At 3000 rpm, the amount added is 1/2 of the bearing cavity. Mini Car Vacuum Cleaner,Cordless Car Vacuum Cleaner,Car Cordless Vacuum Cleaner,Rechargeable Car Vacuum Cleaner Ningbo ATAP Electric Appliance Co.,Ltd , https://www.atap-airfryer.com
3. Daily inspection contents and methods
4, monthly inspection content and method
Electrical equipment maintenance
I. Transformer and power equipment inspection items and contents