Precautions For Safe Use Of Submersible Pumps

Feb 17, 2025

1. Install leakage protector
Leakage protector, also known as life protector, can be understood from the three words "life protector". Because submersible pumps work underwater, they are prone to electrical leakage, which can cause energy loss and even lead to 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 not exceeding 30mA), the leakage protector will cut off the power supply of the submersible pump to avoid energy waste caused by leakage and ensure safety.
2. Do not turn on the power supply if the voltage is abnormal
Due to the relatively long low-voltage power supply lines in rural areas, it is common for the terminal voltage of the lines to be too low. When the phase voltage is lower than 198 volts and the line voltage is lower than 342 volts, the speed of the submersible pump motor decreases. When it does not reach 70% of the rated speed, the centrifugal switch will close, causing the starting winding to be energized for a long time and generate heat or even burn out the winding and capacitor. On the contrary, excessive voltage can cause 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 all times. If it is below 10% of the rated voltage and above 10% of the rated voltage, the motor should be stopped to identify the cause and eliminate the fault.
3. Avoid frequent switching
Do not frequently turn on and off the submersible pump, as it will generate backflow when the electric pump stops. If it is turned on immediately, it will cause the motor load to start, resulting in excessive starting current and burning out the winding. Due to the high current during startup, frequent startups can also burn out the windings of the submersible pump motor.
4. Do not let the submersible electric pump work under overload for a long time
To avoid long-term overload operation of submersible electric pumps, do not pump water with high sediment content and observe whether the current value is within the specified value on the nameplate at any time. If excessive current is found, stop the machine for inspection. In addition, the dehydration operation time of the electric pump should not be too long to avoid overheating and burning out the motor.
5. The rotation direction of the motor should be correct
The rotation direction of the motor should be clarified. There are many types of submersible pumps that can produce water in both forward and reverse directions, but the water output is small and the current is high in reverse. If the reverse time is long, it will damage the motor winding.
6. Cable installation and insulation resistance requirements for submersible electric pumps
When installing a submersible pump, the cable should be overhead and the power line should not be too long. When diving or lifting the submersible pump, do not put force on the cable to avoid causing the power line to break. When the submersible pump is working, do not sink into the mud, otherwise it may cause poor heat dissipation of the motor and burn out the motor winding. During installation, the insulation resistance of the motor should not be less than 0.5 megohms.
7. Check and inspect frequently, discover problems and fix them in a timely manner
Regularly check the motor. If cracks are found on the lower cover, damaged or ineffective rubber sealing rings, etc., they should be replaced or repaired in a timely manner to avoid water infiltration into the submersible pump.
Submersible pumps are used for domestic water supply, mining emergency rescue, industrial cooling, farmland irrigation, seawater lifting, ship loading, and can also be used for fountain landscapes. Hot water submersible pumps are used for hot spring bathing, and can also be used for extracting groundwater from deep wells. They can also be used for water extraction projects such as rivers, reservoirs, and canals. Mainly used for farmland irrigation and water supply for people and livestock in high mountain areas, it can also be used for central air conditioning cooling, heat pump units, cold pump units, urban, factory, railway, mining, and construction site drainage. The general flow rate is (10m3~650m3) per hour, and the head can reach 1500 meters. Inclusion: Submersible pumps are compact and lightweight, playing an important role in rural production and life. The following points should be noted during use.
1, When choosing a submersible pump, attention should be paid to its model, flow rate, and head. If the selected specifications are inappropriate, sufficient water output will not be obtained and the efficiency of the unit will not be fully utilized. In addition, the direction of rotation of the motor should also be clarified. Some types of submersible pumps can produce water in both forward and reverse directions, but the water output is small and the current is high in reverse, which can damage the motor winding. To prevent electric shock accidents caused by leakage during underwater operation of submersible pumps, a leakage protection switch should be installed.
2, When installing a submersible pump, the cable should be overhead and the power line should not be too long. When the unit is launched, do not put any force on the cables to avoid causing the power lines to break. Do not sink the submersible pump into the mud, otherwise it may cause poor heat dissipation and burn out the motor winding.
3, Try to avoid starting up at low voltage. The power supply voltage should not differ from the rated voltage by more than 10%. If the voltage is too high, it can cause the motor to overheat and burn out the winding. If the voltage is too low, the motor speed will decrease. If it does not reach 70% of the rated speed, the centrifugal switch will close, causing the starting winding to be energized for a long time and generate heat or even burn out the winding and capacitor. Do not frequently turn on and off the motor, as it will generate backflow when the electric pump stops. If you start it immediately, it will cause the motor load to start, resulting in excessive starting current and burning out the winding.
4, Never let the submersible pump operate at overload for a long time. Do not pump water with high sediment content. The dehydration operation time of the submersible pump should not be too long to avoid overheating and burning out the motor. During the operation of the unit, the operator must observe at all times whether the working voltage and current are within the values specified on the nameplate. If they do not meet the requirements, the motor should be stopped to identify the cause and eliminate the fault.
5, Regularly check the motor. If cracks are found on the lower cover, damaged or ineffective rubber sealing rings, etc., they should be replaced or repaired in a timely manner to prevent water from seeping into the machine.