Use and maintenance of deep well submersible pumps  

- 2021-09-26-

Use and maintenance of deep well submersible pumps

1. Start:
(1) Electric pumps below 11 kilowatts are allowed to start directly, and electric pumps above 13 kilowatts should be equipped with a step-down starting cabinet to protect the safe operation of the electric pumps.
(2) In order to prevent the rotor of the electric pump from moving up instantly and reduce the starting load, when the electric pump is started, the stroke of the outlet valve should be closed to 3/4 (leave 1/4 air gap for venting) until the water is started and the water is discharged slowly. Turn it on until the pump working condition point is controlled in an appropriate position.
(3) After the start-up is completed and the operation is started, monitoring and observation of water level changes should be strengthened to ensure that the electric pump operates within the working condition range, and the electric pump can be put into formal operation after it runs smoothly.
(4) After the deep well submersible pump is put into operation for the first time for 5 hours, the thermal insulation resistance is measured immediately after it is shut down, and the value is not less than 0.5MΩ before it can be used continuously.

2. Stop the pump:
Before shutting down the deep well submersible pump, in order to prevent the backflow of water, the valve must be closed while the power supply is cut off, and the interval between restarts is more than 20 minutes.

3. Deep well submersible pump operation and maintenance:
(1) Deep well submersible pumps should work at the design operating point, when the axial force is moderate, the pump efficiency is the highest, and the most economical and reliable.
(2) The deep-well submersible pump must be fully inspected every 8 hours of operation, whether each instrument has changed, whether the circuit node is hot, and whether the sound is normal.
Whether the normal working current of the deep well submersible pump is greater than the rated value of the motor nameplate.

4. In one of the following situations, the pump should be stopped immediately:
(1) The working current of the deep well submersible pump is suddenly higher than the rated current of the motor
(2) Abnormal water output, intermittent water output, increased sand content
(3) The insulation resistance of the motor is less than 0.5 megohm
(4) The unit has obvious noise and vibration aggravated
(5) The grid voltage is insufficient, less than 5% of the rated voltage
(6) One phase of the fuse is burned out

(7) Damaged water pipeline

5. Precautions for use and maintenance:
(1) Check the current, voltage and outlet pressure every day, check the dynamic water level every 2 weeks, and make a record.
(2) Check the insulation resistance of the motor every four weeks and make a record.
(3) Minimize the number of starts during use.
(4) If the deep well submersible pump is not used continuously after going down the well, it should be turned on once a week and run for 5-10 minutes to prevent the electric pump from being unable to start due to corrosion.

6. Storage and handling of deep well submersible pumps:
When storing deep well submersible pumps, drain the water in the motor cavity, wipe the surface dry, and apply anti-rust grease to the shaft head and coupling, and place it upright. (To prevent rotor deformation) Store in a dry, non-chemically corrosive material, at room temperature, and the temperature should not be lower than -3°C during winter storage.