1. Check for the vulnerable parts: impeller, buckle, axle sleeve and bearing seat of the submersible pump are vulnerable parts. First of all, the water pump should be removed to check for the integrity of the vulnerable parts. The use of damaged and unqualified parts is strictly prohibited.

2. Replace the lubricant: open the sealing chamber and the oil hole screw inside the motor, and release all the lubricating oil of the sealed chamber and motor. Replace the new oil to ensure the lubrication system works properly.

3. Remove pump shell to prevent rust: before use in spring, the top pump shell should be disassembled, and then the impeller will be turned on to start, so as to prevent the rust of the parts from starting and burning the motor. This maintenance is particularly important for water - filled motor.

4. Ensure that the seal: the agricultural submersible pumps are very strict in sealing. When replacing the sealing oil, if the oil is cloudy and the water content is high, then the sealing box or sealing ring must be replaced to ensure its sealing performance.

5. The drying machine: the insulation resistance of the winding and casing of the submersible pump is measured with a 500 megohm meter. If the resistance value is lower than 0.5 megohm, the motor water should be expelled. The drying methods include: external drying method, current drying method and combined drying method. The external drying method is to use external heat source to process, the commonly measure: 1) Blowing hot wind: the blower of electric heater (a small submersible pump can be used to blow the air) to blow hot air to achieve the purpose of drying; 2) Light bulb bake: in a closed box, bake with several 200 watt light bulbs. Pay attention to the baking temperature not too high, it should be controlled under 125 ℃. 3) Current drying: based on the impedance of the submersible pump and the size of the power supply, the three-phase winding of the motor will be connected in series or parallel, and then connected to a variable resistor. Adjust the electric flow rate of the rated value of 60% or so, the electric drying.

6. Bearing lubrication. The skeleton oil seal and lithium base grease of the upper and lower end bearing chamber should be checked and replaced by water filling submersible pump. To ensure that the bearings are permanently lubricated in good condition.

7. Check the bearing. Check the upper and lower bearings of motor parts. New bearings should be replaced in case of excessive abrasion or excessive gap. The check method is as follows: if the motor is running, with "Ka thump" sound, and the cycle is proportional to the speed, and the rotation of the rotor with the hand feeling is laborious, this is the phenomenon of avulsion on the raceway of the bearing; If there is a continuous "stick" sound in the bearing, there is an uncertain dead point when turning the rotor with the hand. Generally, the ball frame is damaged, the inner ring is broken or the ball is broken. In case of the above situation, the bearings must be replaced so as not to cause greater damage.