3LSS/4LSS Screw-Type Solar Home Submersible Pump

This is a type of DC water pump, characterized by its screw (positive displacement) working principle, specifically designed for pumping water from deep wells using solar power.

Model Interpretation:
3LSS / 4LSS: Typically represents the pump body diameter specifications (3 inches ≈ 76mm, 4 inches ≈ 100mm), and the code for a "screw-type submersible pump".
LSS: Often represents "vertical, screw, deep well," etc.
Core Components: It consists of a brushless DC motor, a screw pump head (rotor + stator), and a built-in controller.
Core Working Principle: Photovoltaic conversion + helical propulsion
This system's workflow is very green and environmentally friendly, mainly divided into two steps:
Photovoltaic Conversion: Solar panels convert sunlight into DC electricity.
Positive Displacement Water Pumping: The current drives the brushless DC motor to rotate, driving the screw (rotor) inside the rubber stator. Through the sealed chambers formed by the engagement of the screw and stator, the well water is smoothly "pushed" up along the helical direction.
Why do solar pumps prefer the "screw" structure?
Because solar power generation is affected by weather, resulting in unstable voltage and power. Screw pumps have the characteristics of low speed and high torque, and can maintain operation even at lower voltages (insufficient sunlight) (although the flow rate decreases), while ordinary centrifugal pumps may not start at all with insufficient voltage.
Key Features: Dry-running protection, sand resistance, wide voltage range

Feature Detailed Description
Wide Voltage Operation  Can adapt to fluctuations in solar power. For example, a pump rated at 24V can often operate normally between 20V and 36V.
Dry-Running Protection  With a solar controller, even if the well water runs dry, the pump will automatically stop or run at a low speed, preventing it from burning out instantly like ordinary pumps.
Dirt and Wear Resistant  The screw structure is not sensitive to water quality and is very suitable for rural well water and water sources with slightly higher sand content, which is why it is more durable than ordinary solar centrifugal pumps.
Maintenance-Free Brushless Motor  Uses a brushless design, has a long lifespan, and does not require regular brush replacement, making it ideal for installation in deep wells where maintenance is difficult.

Typical Application Scenarios
This series of pumps is an excellent solution for off-grid water extraction, mainly used in:
Drinking water projects in areas without electricity:
In mountainous and pastoral areas without grid coverage, solar energy is used to directly draw water from deep wells for human and animal consumption.
Precision agricultural irrigation:
Used in greenhouse drip irrigation or micro-sprinkler systems. Because screw pumps provide stable water pressure, they are very suitable for irrigation scenarios requiring constant pressure water supply.
Household wells:
Families use rooftop solar panels to power the pump for daily water use such as washing vegetables and watering flowers, saving energy and electricity costs.
Livestock farming:
Automatic water replenishment for cattle and sheep drinking troughs in pastures.

Selection and Usage Suggestions
Matching Solar Panel Power:
These pumps usually have specific voltage levels (such as 24V, 48V, 72V, etc.). You need to configure solar panels with corresponding open-circuit voltage and peak power according to the pump's rated power.
Regarding Head and Flow Rate:
3LSS series (3-inch): Usually used for low flow rate and high head scenarios (such as heads of tens or even hundreds of meters, and flow rates of several hundred liters to about 1 ton per hour).
4LSS series (4-inch): Larger well diameter, usually used for scenarios requiring larger flow rates (such as about 2 tons per hour), but the head may be relatively lower.
Anti-freezing and Storage:
Although made of stainless steel (usually 304/316), if not used for a long time during the winter in northern regions, it is recommended to remove the pump from the water to prevent freezing and cracking of the pump body or freezing of the cable.

The 3LSS/4LSS series screw-type solar pumps are the "green heart" for deep well water extraction. If your area has difficulty with grid power supply, or you want long-term operation with zero electricity costs, and the well water contains a small amount of sediment, then choosing this series of screw pumps is a highly cost-effective solution.