1. How to use the submersible pump
(1) Environmental requirements for use
1. Have a safe and reliable power supply .
2. The drop between the outlet pipe and the water surface of the pool should be less than the head.
3. Choose a relatively clean water source.
(2) Startup
1. Submersible pumps below 11 kW are allowed to start directly, and submersible pumps above 13 kW should be equipped with a depressurization starting cabinet. To protect the safe operation of submersible pumps.
2. In order to prevent the rotor of the submersible pump from jumping up instantly and reduce the starting load, when the submersible pump is started, the stroke of the outlet valve should be closed to 3/4 (leave a 1/4 air gap for deflation). ), slowly open after starting the water outlet, until the pump operating point is controlled in an appropriate position.
3. After the start-up and start of operation, the monitoring and observation of the water level changes should be strengthened to ensure that the submersible pump operates within the working conditions.
4. After the submersible pump is put into operation for the first time for 5 hours, the thermal insulation resistance should be measured quickly after shutdown, and the value should not be lower than 0.5MΩ before continuing to use.
(3) Operation
1. The submersible pump should work at the design operating point, where the axial force is moderate, the pump efficiency is the highest, and the most economical and reliable .
2. The submersible pump should be fully checked every 8 hours to check whether there is any change in each instrument, whether the circuit node is hot, whether the sound is normal, and whether the normal operating current is greater than the rated value of the motor nameplate.
Note that the pump should be stopped immediately in one of the following situations:
1) The working current of the pump is suddenly higher than the rated current of the motor.
2) The water output is abnormal, intermittent water is produced, and the sand content increases.
3) The insulation resistance of the motor is lower than 0.5 megohm.
4) The unit has obvious noise and vibration aggravated.
5) The grid voltage is insufficient, 5% lower than the rated voltage.
6) The fuse burns out one phase.
7) The water pipeline is damaged.
(4) Stop the pump
Before the submersible pump stops, in order to prevent the backflow of water, the valve should be closed when the power is cut off, and the interval between restarts should be more than 20 minutes.
2. Precautions for the use of submersible pumps
1. Install leakage protectors
Leakage The protector is also called a life saver, and its function can be understood from the three words “life saver”. Because the submersible pump works underwater, it is easy to leak electricity, resulting in power loss and even electric shock accidents. If a leakage protector is installed, as long as the leakage value of the submersible pump exceeds the operating current value of the leakage protector (generally no more than 30 mA), the leakage protector will cut off the power supply of the submersible pump to avoid leakage and waste of electric energy and ensure safety.
2. Do not start the machine when the power supply voltage is abnormal
In rural areas, due to the relatively long low-voltage power supply lines, it is common for the voltage at the end of the line to be too low. When the phase voltage is lower than 198 volts and the line voltage is lower than 342 volts, the motor speed of the submersible pump will drop. When it does not reach 70% of the rated speed, the start centrifugal switch will be closed, causing the start winding to be energized for a long time and heat up or even burn out. windings and capacitors. On the contrary, the high voltage causes the motor to overheat and burn out the windings. Therefore, during the operation of the submersible pump, the operator must observe the power supply voltage value at any time. If it is less than 10% of the rated voltage and more than 10% of the rated voltage, the motor should be stopped to find out the cause and eliminate the fault.
3. Avoid frequent switching
Do not switch the submersible pump frequently, this is because backflow will occur when the electric pump stops, if it is turned on immediately, it will Start the motor load, resulting in excessive starting current and burn out the windings. Due to the large current at startup, frequent startup will also burn out the submersible pump motor windings.
4. Do not allow the submersible pump to overload for a long time
In order to avoid the long-term overload of the submersible pump, do not pump water with high sand content And observe whether the current value is in the value specified on the nameplate at any time. If the current is found to be too large, it should be stopped for inspection. In addition, the dehydration time of the electric pump should not be too long, so as not to overheat the motor and burn it.
5. The rotation direction of the motor should be correct
The rotation direction of the motor should be understood. Water can be discharged, but the water output is small and the current is large during reversal, and the motor winding will be damaged if the reversal time is long.
6. Cable installation and insulation resistance requirements of the submersible pump
When installing the submersible pump, the cable should be overhead, and the power cable should not be too long. Do not apply force to the cable when the submersible pump is launched or lifted, so as not to cause the power cord to break. Do not sink into the mud when the submersible pump is working, otherwise it will cause poor heat dissipation of the motor and burn the motor windings. During installation, the insulation resistance of the motor should not be lower than 0.5 megohms.
7. Check frequently and find problems and repair them in time
Always check the motor frequently, such as cracks in the lower cover, damage or failure of the rubber sealing ring etc., should be replaced or repaired in time to avoid water infiltration into the submersible pump.
