Operation, Maintenance, and Servicing of Deep-Well Pumps

1. During the operation of the electric pump, frequently monitor the current, voltage, and water flow rate, striving to maintain operation within the rated parameters.

 

2. Use valves to regulate flow and head; do not operate under overload conditions.
Stop operation immediately if any of the following occur:
1) Current exceeds the rated value at rated voltage;
2) Flow rate drops significantly below normal levels at the rated head;
3) Insulation resistance falls below 0.5 MΩ;
4) Dynamic water level drops to the level of the pump intake;
5) Electrical equipment or circuitry fails to meet standards;
6) The pump produces sudden, unusual noises or excessive vibration;
7) The protection switch trips frequently.

 

3. Continuously monitor the instruments and inspect the electrical equipment; measure the motor insulation resistance every two weeks-the value must not be lower than 0.5 MΩ.

 

4. Perform maintenance and servicing after every irrigation/drainage cycle (2,500 hours of operation) and replace any worn parts.

 

5. Lifting and handling the electric pump:
1) Disconnect the cable and the power supply.
2) Using installation tools, gradually disassemble the discharge pipe, gate valve, and elbow; secure the next section of the discharge pipe with a pipe clamp, and repeat this process section by section to lift the pump out of the well. (If the pump gets stuck during lifting, do not force it; maneuver it up, down, left, and right to clear the obstruction before proceeding safely.)
3) Remove the cable guard and intake screen, then cut the cable at the connection point between the lead wire and the three-core or flat cable.
4) Remove the locking ring from the coupling, unscrew the fixing screws, remove the connecting bolts, and separate the motor from the pump.
5) Drain the water from the motor.
6) Disassembling the pump: Use a disassembly wrench to unscrew the intake section (turn counter-clockwise); use a disassembly sleeve to strike the tapered sleeve at the bottom of the pump; once the impeller loosens, remove the impeller and tapered sleeve, then remove the diffuser casing; continue this sequence to remove the remaining impellers, diffusers, upper diffuser casing, check valve, etc. 7) Motor disassembly: Remove the base, thrust bearing, thrust disk, lower guide bearing housing/adapter, and water slinger in sequence; remove the rotor; then remove the upper guide bearing housing, stator, etc.

 

6. Assembly of the electric pump:
(1) Motor assembly sequence: Stator assembly → lower guide bearing assembly → rotor assembly → thrust disk → left-hand threaded nut → thrust bearing assembly → base assembly → upper guide bearing housing assembly → skeleton oil seal → adapter. Adjust the stud to ensure the motor shaft extension meets specifications. Then, install the pressure-regulating diaphragm, pressure-regulating spring, and cover.
(2) Water pump assembly: Secure the shaft and water inlet section to the mounting base; use the assembly sleeve to fix the impeller and tapered sleeve onto the shaft; then install the diffuser casing, impeller, etc., continuing the sequence to install the upper flow casing, check valve, etc.

When assembling the pump section (for units with 8 stages or fewer), first evenly tighten the tensioning nuts at the contact surface between the water inlet section and the upper guide bearing housing; install the coupling, pump shaft, fixing studs, and locking rings; use the assembly sleeve to fix the impeller and tapered sleeve onto the pump shaft; then install the diffuser casing, impeller, etc., continuing the sequence to install the upper diffuser casing. After the pump is assembled, loosen the tensioning nuts, remove the spacers, and then evenly retighten the tensioning nuts; finally, rotate the electric pump via the coupling to ensure smooth, uniform rotation.