How to connect cables of a deep well submersible pump?

1. Strip off the outer jacket and primary insulating layer of the deep well pump cables, baring 35~40mm copper wire. Make the rubber close to the cable core into the shape of cone. Polish and clear away the oxide layer of the cable core. Use alcohol (hydrochloric acid is better) to clean the cable core, insulating layer to be wrapped and the layer of sheath, wait until they dry naturally in the air.

2. Connecting the ends

1) Power cable 2) polyvinyl chloride adhesive tape 3) self-adhesive butyl rubber tape 4) φ1mm copper wire 5) soldering tin 6) Outgoing cable

3. Prepare a 500W electric soldering iron, rosin, soldering tin, 1 mm bare copper wire and insulating tape.

4. Fasten the cable core evenly with bare cooper wire. Use the electric soldering iron to heat the tin and let the melted tin penetrate thoroughly and evenly into the fastened cable core.  Use a rasper to amend the welding part to make it flat, with no burrs or sharp edges. Wipe it clean with alcohol again, and let it dry naturally in the air.

5. First, use self-adhesive butyl rubber tape to wrap it in three half-lapped layers gradually reaching toward the outside of the cable core. When wrapping, you must pull the adhesive tape to make it stretch to 200% larger. Use polyvinyl chloride adhesive tape to wrap again in three half-lapped layers, gradually reaching toward the outside of the cable core as before. Make sure the wrapped part is not shorter than 200mm.

6. When connecting the three-core cable, you should keep the three connections separated from each other by some distance to prevent short circuit.

7. The way of connecting double outgoing cables

1) After connecting the cables, you should measure the insulation resistance between cable and the motor (not filled with water) remotely. The measured value is normally not lower than 150MΩ.

2) When the motor has been filled with water, you should measure again the insulation resistance of motor windings remotely. The measured value should not be lower than 40MΩ.

3) Power on the motor for less than 2 seconds to test its rotation direction. Mark the position and order of the phases.

4) Now we begin to put the pump down into the well. During this process, you should keep measuring its insulation resistance remotely and observe the changing for fear that the insulation layer of the cable is scraped by the wall of the well. If you find the insulation resistance drops sharply below 0.5MΩ, you should pull the pumping unit up and identify and causes.  If no accidents happen, after putting the pump down into the well, you can start it up for a test run according to the steps we talked about previously.