1. Replace lubricating oil: Open the oil hole screws inside the sealing chamber and the motor respectively, drain all the lubricating oil inside the sealing chamber and the motor, replace with new oil, and ensure the normal operation of the lubrication system.

2. Inspect vulnerable parts: The impeller, retaining ring, shaft sleeve, bearing seat, etc. of the submersible pump are vulnerable parts. Firstly, the water pump part should be removed to check if the vulnerable parts are intact. It is strictly prohibited to use damaged and unqualified spare parts.

3. Disassemble the pump casing to prevent rusting: Before use in spring, the previous stage pump casing should be disassembled, the impeller should be rotated, and then the switch should be closed to start, in order to prevent rusting of components and failure to start normally, which may burn out the motor. This maintenance is particularly important for water filled electric motors.

4. Drying motor: Use a 500 megohmmeter to measure the insulation resistance between the winding and the casing of the submersible pump. If the resistance is less than 0.5 megohms, the motor should be drained of moisture. Drying methods include external drying, electric current drying, and combined drying of both. External drying method refers to the use of external heat sources for treatment, and commonly used measures include:
⑴ Blowing hot air: Use the blower of the electric heater (electric hair dryer can be used for agricultural small submersible pumps) to blow hot air to achieve the purpose of drying treatment;
⑵ Light bulb baking: Use several 200 watt light bulbs for baking in a sealed box. Pay attention to the baking temperature, which should not be too high and should be controlled below 125 ℃;
⑶ Current drying: The three-phase windings of the electric motor can be connected in series or parallel according to the impedance of the submersible pump and the size of the power supply, and then a variable resistor can be connected to adjust the current to about 60% of the rated current value, and then dried with electricity.

5. Ensure sealing: agricultural usesubmersible pumpThe requirements for sealing are very strict. When replacing the lubricating oil in the sealing chamber, if the oil quality is turbid and the water content is high, the entire sealing box or sealing ring must be replaced or replaced to ensure good sealing performance.