1：Never be grounded
Protective grounding of submersible pumps is a requirement of national mandatory standards.
Only by taking protective grounding, can we ensure personal safety during use.
If there is no protective grounding, once the casing leaks, it will cause the water at the outlet of the submersible pump and the pumped water to be electrified, endangering the safety of people and animals, and wasting a lot of electrical energy.
If the metal casing of the submersible pump is connected to the grounding body (grounding resistance is not greater than 4Ω) that meets national standards
When the submersible pump casing leaks, the current forms a closed loop through the submersible pump metal casing, protective ground wire, ground body, earth, transformer working ground wire and power supply
When the leakage current is too large, especially when the live wire hits the shell, the protective device of the submersible pump can be activated (the fuse is blown or the air switch is tripped), and the power supply of the submersible pump is cut off.
2: No leakage protector is not installed
Submersible pumps work in water, which is easy to cause electricity loss and even cause electric shock.
If a leakage protector is installed, as long as the leakage current 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 of the submersible pump.
3: Start the pump when the power supply voltage is abnormal
Too high and too low voltage will make the submersible pump temperature rise too high, shorten the service life or even burn the submersible pump.
Therefore, in the process of using the submersible pump, the operator must observe the voltage value of the power supply at any time. Stop and avoid starting when the power supply voltage is abnormal.
4: The motor rotates in the opposite direction
At present, there are many types of submersible pumps that can produce water in both forward and reverse directions. However, when the water is reversed, the water output is small and the current is large. If the reverse time is long, the motor winding will be damaged.
Therefore, before entering the water, the submersible electric pump should be connected to the power supply to check whether the rotation direction is correct. If the impeller of the three-phase submersible pump is reversed, it should be stopped immediately, and the wiring of any two phases of the three-phase core wire in the cable can be replaced.
5: Long-term overload work of submersible pump
To avoid long-term overloading of submersible pumps, do not use low-lift pumps for high-lift work.
Do not pump water with high sand content (heavy mud).
And observe whether the current value is within the specified range at any time.
If you find that the current is too large, you should stop and check.
In addition, submersible pumps use water as a cooling source, so the dehydration operation time of submersible pumps should not be too long.
6: No frequent switching
The submersible pump should not be started too frequently, this is because the submersible pump will produce backflow when stopped
If it is turned on immediately, it will start the motor load and cause excessive starting current.
Therefore, after the shutdown, it is necessary to wait for the backflow of the stored water in the pipe to start again, generally it takes about 5 minutes.
7: Do not use it in a silt environment
If the submersible pump sinks into the mud during use, it will cause poor heat dissipation and burn out the motor winding
Therefore, the submersible pump must not be used in a sludge environment.
In order to prevent the submersible pump from sinking into the sludge, the sludge in the working environment should be removed before the submersible pump is launched. If necessary, the submersible pump should be covered with a fence shield to avoid blocking the waste into the water fence and causing the motor to heat up 3. Poor water flow.
8: When the submersible pump is not working, the submersible pump is not removed from the water in time
If the submersible pump is not used continuously after launching, it will corrode after a long time, resulting in failure to start.
Therefore, the deactivated submersible pumps should never be left in the water regardless of whether they are turned on or off. They should be turned on once a week and run for 5 to 10 minutes.
When not in use for a long time, it is best not to be immersed in water for a long time. It should be put in clean water and run for a few minutes to clean the mud inside and outside the pump. Descaling, replace the wearing parts, and then reassemble it, put it in a dry, non-corrosive gas warehouse after painting and anti-rust.
