AS/AV Cutting Submersible Sewage Pump

Operating Manual

Precautions

1. Never lift or suspend the pump by its power cable. For handling or lifting, attach a chain with hooks to the handle or lifting eye on the top cover.

2. For mobile use, connect a discharge hose of the specified standard bore (see table) to the discharge elbow using a suitable hose coupling. For fixed installations, design the discharge pipeline according to the flange standard of the auto-coupling device.

3. The pump must not be placed at the outlet of the sewage flow. When placed on soft mud or loose sand, vibration may cause the pump to sink. In this case, it is recommended to suspend the pump or place it on a larger base plate.

4. If the pump continues to operate at ambient temperatures below 0°C, it may remain in service; however, once it is stopped, it should be lifted out, cleaned, and stored properly to prevent freezing damage.

5. The inside diameter of the discharge pipe should comply with the specified requirement. For long-distance discharge, the diameter may be reduced slightly if necessary, but excessive reduction can cause clogging and reduced efficiency, which is not economical.

6. When the pump is used in sewage, sludge and other deposits may accumulate around the casing after long-term operation, reducing heat transfer and causing the internal temperature of the pump to rise, shortening motor life or causing nuisance tripping. Therefore, after each period of operation (for example, when the level drops to the low water level), flush the pump with clean water to keep it clean.

7. The mechanical seal is lubricated and cooled by No. 10–30 mechanical oil. Due to seal wear, lubricant can leak out and the pumped medium may enter the motor through the seal. In this case, send the pump to our factory service department or an authorized service center for seal replacement as soon as possible to avoid motor damage.

8. Do not move the pump or touch the surrounding water when the power supply has not been disconnected. If the pump leaks electricity and no earth leakage circuit breaker is installed, electric shock accidents may occur.

9. After installation, the submersible pump should not be left immersed in water for long periods without operation, as this increases the risk of motor moisture ingress. It is recommended to run the pump for at least 4 hours each week to check performance and suitability. Otherwise, lift the pump and store it in a dry place.

Electrical Protection

1. A qualified electrician must check the system before start-up to ensure that all required electrical protection measures are in place.

2. Before operation, measure the insulation resistance between motor phases and from phases to ground with a 0–500 V megohmmeter; the minimum value must be greater than 2 MΩ.

3. The power supply must be safe, reliable, and stable. Voltage and frequency must meet the specified requirements (voltage: 380 V ±5%, frequency: 50 Hz ±1%), and instantaneous voltage deviation must not exceed 10%. If the distance between the power supply and the pump is considerable, use a cable with a larger cross-sectional area and minimize joints to avoid excessive voltage drop. Seal all cable joints to prevent water ingress and leakage.

4. In the four-core cable, the conductor marked with the symbol “⊥” is the protective earth (typically green-yellow dual-color or black). For safe operation, the earth conductor must be firmly connected and made about 50 mm longer than the other conductors.

5. Where possible, electrical protection devices should include an earth leakage protection relay and a ground-fault circuit breaker. In all cases, fuses must be of the slow-blow type and matched to the rated current of the pump.

6. The electrical control cabinet should be protected from moisture and installed in a dry area. Route the power cable so that it cannot be sucked into the pump inlet or obstruct the suction.

Direction Check

1. After the first start-up or any reinstallation, verify the rotation direction. Incorrect rotation will reduce pump efficiency and may cause impeller loosening or other damage. To check the direction:
   a) Looking down from the top of the pump, the rotor should rotate clockwise.
   b) Looking up from the bottom (suction side), the impeller blades should appear to rotate counterclockwise.

2. If several pumps are connected to the same control unit, each pump must be checked individually. If the rotation direction is incorrect, swap any two phases in the controller to correct it.

Maintenance & Service

AS pumps are robust and reliable. Every unit is carefully tested before leaving the factory. Grease-lubricated ball bearings give the pump long service life. However, to ensure durability, regular inspection and maintenance are strongly recommended.

1. Adjustment of Bottom Cover Plate
   After prolonged operation in abrasive media, the gap between the impeller and the bottom cover plate may increase. Disconnect the power, loosen the fixing screws, and rotate the cover plate to readjust the clearance to its original value (0.3–0.5 mm).

2. Cleaning
   To prevent solids from remaining inside the pump when it is out of service, run the pump with clean water to flush the interior. For long shutdown periods, store the pump in a dry place and protect it from freezing.

3. Oil Filling and Replacement
   Before shipment, the oil chamber of the AS cutting submersible sewage pump is filled with an appropriate quantity of lubricant. This oil should be replaced annually as follows:

   • Place the pump so that the oil plug of the oil chamber (located on the inner side of the discharge outlet) faces downward. Loosen the plug and drain the oil.

   • Rinse the oil chamber with flushing oil, then refill with fresh lubricant (about 70–80% full).

   • Replace the O-ring with a new one and tighten the plug. If the oil appears milky (emulsified), flush the chamber and refill with fresh oil and a new O-ring. Recheck after about three weeks. If the oil becomes milky again, the mechanical seal must be inspected and, if necessary, replaced (contact our service department). If the seal is replaced by the user, a pressure tightness test must be performed (air pressure 0.5 kg/cm²).

   • Recommended lubricant: No. 10 mechanical oil.

4. Operating Faults
   If a fault occurs during operation and the cause cannot be identified, and the countermeasures described in the troubleshooting guide do not solve the problem, do not improvise or disassemble the pump at random. Instead, contact our service department. This is especially important for repeated tripping caused by overcurrent protection in the control circuit.

Installation Precautions

Correct installation and operation are the basic guarantee for long-term, trouble-free service. Users should pay particular attention to the following:

1. The pump power cable must be connected via the dedicated control panel or a properly matched thermal overload relay and must not be connected directly to the main power supply.

2. Whether in mobile or fixed automatic installation, neither the lifting chain nor the power cable may hang too loosely to avoid being sucked into the pump and cut by the impeller.

3. If the bottom of the sump contains thick sludge or large stones, place the pump at least 30 cm above the deposits or mount it on a large steel base plate.

4. The discharge pipeline must be selected and installed as specified in the instructions; do not modify the discharge line arbitrarily.

5. For a single pump installation where backflow cannot occur, it is preferable not to install a check valve.

6. For two pumps in parallel, do not install the gate valve and check valve only on the main header, otherwise, backflow of sediment into the standby pump may prevent the check valve from closing properly. Where possible, install a dry pit on the manifold and mount the check valves and gate valves there.

7. Only after confirming the correct direction of rotation may the pump be put into continuous operation.

8. During long-term service, whether in automatic or manual mode, the pump must not be started too frequently. As a guideline, the number of starts should not exceed six times per hour.

9. Always disconnect the power supply before carrying out any maintenance work on the pump.