Maintenance knowledge of submersible sewage pump

The submersible sewage pump has the advantages of small size, convenient installation and maintenance, no noise, stable operation, etc. Especially compared with the traditional dry pump station, it simplifies the underground structure, reduces the ground area, and even does not occupy the ground buildings, greatly reducing the project cost of the pump station. At present, the submersible sewage pump has gradually replaced the traditional dry pump.

Maintenance tips

① Regularly check the insulation resistance between motor phases and between motor phases and ground. The value shall not be less than 2 megohms, or the machine shall be disassembled for maintenance. At the same time, check whether the water pump is firmly grounded.

② Each time the water pump is installed, check whether the rotation direction of the motor is correct. The correct rotation direction is: when looking up from the suction port of the pump, the impeller rotates counterclockwise. If the direction of rotation is incorrect. The position of any two phase lines in the three-phase can be exchanged. If several pumps are connected to the same control cabinet, each pump must be checked.

③ Before the water pump runs, check the power supply voltage value. The voltage is not allowed to exceed ± 10% of the rated voltage.

④ Water pumps are filled with mechanical oil to lubricate seals before leaving the factory. The oil shall be checked regularly every year. If the oil is emulsified or water precipitates, the 10-30 mechanical oil and mechanical seal shall be replaced in time. The water pump used under severe conditions shall be overhauled frequently.

⑤ Under normal working conditions, after one year of operation, the water pump shall be overhauled to replace worn wearing parts and check the status of fasteners. For pumps equipped with wear rings, wear rings shall be replaced when the maximum wear clearance between impeller and wear rings in the diameter direction exceeds 2mm.

⑥ In order to prevent impurities from accumulating inside the water pump after many times of use, clean water can be used to clean the water pump, especially the lower seal to avoid caking and blocking.

⑦ When the water pump is not used for a long time, it should be taken out of the water to avoid long-term immersion in the water, so as to reduce the probability of the motor being affected with damp and increase the service life of the water pump. It is forbidden to pull the cable by hand to prevent the sealing failure of the cable incoming line. When the temperature drops below 0 ℃, the water pump must be taken out to prevent frost cracking. Note that the water pump shall be flushed with clean water every time it is lifted. If the motor is immersed in water for a long time, it is easy to get damp and the insulation is reduced. Especially for small submersible sewage pump, it is necessary to lift the pump out when it is not used for a long time, and clean the matching part between the impeller and the pump body with clean water to prevent the difficulty of starting the pump due to scaling, accumulation of impurities or corrosion.

⑧ Do not dismantle the pump parts at will, and do not knock and strike fiercely or operate savagely when disassembling to avoid damaging the seals. Do not disassemble the water pump without the guidance of professional technicians to avoid leakage of the water pump and damage to the motor.

⑨ During operation, check the safety, reliability and correctness of various instruments frequently, such as whether the ammeter indicates normally and exceeds the rated value specified on the nameplate.

⑩ The water pump shall be used within the specified range, and the flow shall not exceed the rated flow too much to avoid overload. For most pumps, the outlet gate valve can be closed for adjustment. When the gate is closed, the flow will be reduced, and the corresponding current and power will also be reduced.