Dirty Water Submersible Pump: Everything You Need to Know 

Dirty water submersible pumps operate long-term in impurity-laden, corrosive sewage environments, making them prone to various issues due to complex working conditions. Below are their common problems and corresponding solutions to reduce failures and extend equipment lifespan:

Impeller/Pump Body Clogging

Common Symptoms: Sudden drop in flow rate, motor overload tripping, abnormal noise from the pump body. Causes: Debris such as fibers, plastic bags, and stones in sewage wraps around the impeller, or sludge accumulates and blocks the flow passage. Solutions:

• Shut down the pump, disassemble the pump body, clean debris from the impeller and flow passage, and check if the impeller is wrapped (e.g., by hair or fibers).

• Install pre-installed grilles or filters to pre-filter large particles.

• Choose submersible dirty water pumps with a "cutting function" (equipped with cutting blades at the impeller or inlet) to chop fibrous debris.

Motor Overload (Tripping or Burning)

Common Symptoms: Tripping immediately after startup, sudden shutdown during operation, or overheating of the motor housing. Causes:

• Excessive load due to impeller clogging;

• Worn motor bearings, insufficient lubrication, leading to increased frictional resistance;

• Low power supply voltage or unbalanced three-phase voltage;

• Damp or short-circuited motor windings.

Solutions:

• First, check if the impeller is clogged, clean it, and retry.

• Inspect motor bearings; replace severely worn ones and regularly add lubricating grease (use special grease matching the model).

• Use a multimeter to test the power supply voltage, ensuring it remains stable within the rated range.

• If the motor is damp, dry the windings and test the insulation resistance (should be ≥0.5MΩ); if short-circuited, rewind the windings or replace the motor.

Water Leakage (Motor Water Ingress)

Common Symptoms: Tripping after water enters the motor, activation of leakage protection devices during operation, or severe motor burnout. Causes: Deterioration, wear, or improper installation of the mechanical seal (a core component preventing sewage from entering the motor); poor sealing of cable joints. Solutions:

• Replace the mechanical seal (ensure the correct model is selected; clean the sealing surface during installation to avoid impurities affecting the seal).

• Check for damaged cables; treat joints with special sealant or waterproof connectors to ensure no water seepage.

• Regularly (e.g., every 3 months) inspect the condition of seals and replace aging parts in advance.

Insufficient Head or Reduced Flow Rate

Common Symptoms: Inadequate drainage height or a significant decrease in water discharge per unit time. Causes:

• Impeller wear (long-term conveyance of sand-containing sewage thins the impeller edges);

• Pipe clogging (sludge or debris accumulates in the outlet pipe);

• Insufficient motor speed (unstable power frequency or motor failure).

Solutions:

• Check for impeller wear; replace severely worn impellers (prioritize wear-resistant materials such as cast iron or high-chromium alloy).

• Unclog the outlet pipe and remove sludge accumulated on the inner wall.

• Use a tachometer to measure the actual motor speed; if it is lower than the rated value (e.g., 2900r/min), inspect the power frequency or motor windings.

Abnormal Noise or Severe Vibration

Common Symptoms: Sharp noise during operation, obvious vibration of the pump body, or even shaking of connected pipes. Causes:

• Impeller imbalance (debris stuck in the impeller or uneven wear causing center-of-gravity shift);

• Damaged bearings (worn balls or loose bearing housing);

• Unstable pump installation (loose base fixing bolts or eccentric connection with pipes).

Solutions:

• Disassemble the impeller, clean debris, and replace unevenly worn impellers to ensure balance.

• Replace damaged bearings and re-secure the bearing housing.

• Check base bolts and tighten loose parts; adjust pipe connections to avoid axial/radial force on the pump (use flexible joints to reduce stress).

Insufficient Battery Life

Common Symptoms: Power failure within 1-2 hours after startup, or sudden shutdown during operation, failing to complete long-duration operations. Causes:

• Mismatch between backup power capacity (Wh) and pump power consumption (W). Roughly, battery life = power capacity divided by pump power. For example, a 1000Wh power source powering a 500W pump has a theoretical life of only 2 hours (actual life is shorter due to losses).

• Lithium battery capacity degradation in low-temperature environments (e.g., capacity may drop to below 70% of the rated value when used outdoors in winter).

Solutions:

• Calculate required capacity based on operation duration: For example, a 500W pump needing 4 hours of continuous drainage requires at least 2000Wh capacity (500W×4h=2000Wh; choose 2400Wh or more with 20% redundancy).

• Select backup power sources supporting solar charging (e.g., models with MPPT controllers) for outdoor use, enabling simultaneous charging and operation to extend life (use compatible solar panels).

• In low temperatures, place the backup power source in an insulated bag to reduce capacity degradation.

• Devices like the EcoFlow DELTA 2 Max Portable Power Station offer an excellent solution for addressing the runtime issues of dirty water submersible pumps. Boasting an expandable capacity of 2-6kWh, it meets the needs of long-duration operations, ensuring your sewage pump keeps running even during grid outages. Thanks to its proprietary X-Boost technology, it can power devices with an output power of up to 3100W. When paired with solar panels, it achieves 99% MPPT efficiency, maximizing solar power generation during daylight hours. It is also highly convenient for rural homes and construction sites with limited access to mains electricity, eliminating the need for long-distance cable routing.