(1) check wearing parts. First of all remove the pump part, check the impeller, buckle, sleeve and bearing consumables are intact. Good can continue to use the pump assembly, bad must be replaced. (2) for lubricating oil. Respectively, unscrew the seal chamber and the motor within the hole screw, the sealed chamber and the motor all the internal release of lubricating oil, replace the new oil. (3) to ensure that the seal. When changing the oil in the sealed chamber, if it is found that the oiliness is cloudy and the water content has exceeded 50mL, the moving, static sealing ring or sealing box must be replaced or replaced as a whole. (4) dry. On the insulation resistance of less than 0.5mΩ motor windings, must be dried, dry method with the general motor. If the whole or sealed box is not replaced, you can only remove the stator part of the pump. Under normal circumstances, the whole or sealed box should be as much as possible disassembly, if you really want to disassembly, O-ring rubber seals must be replaced. (5) Check the bearings. Check the motor part of the upper and lower bearings, found excessive wear or clearance is too large, the timely replacement of new bearings. (6) Confirm that the parts are not rusty. Before use should be disassembled pump casing, turn the impeller and then closed to prevent corrosion of parts can not start normally and burn motor windings. This maintenance is especially important for water-filled motors. (7) Make sure the bearings are well lubricated. Water-filled submersible pump should replace the upper and lower cover shaft seal oil seal and lithium-based grease to ensure that the bearing in the work can get good lubrication.