Sewage pump is a kind of pump often encountered in daily maintenance work, often used for municipal sewage, rain water, drainage, the probability of problems is quite high, the reasons for these problems are diverse, can start from three aspects to analyze and solve the problem, respectively: electrical reasons, mechanical reasons, and control reasons.
Common submersible pump wet installation
1. After the motor is powered on, there is no water at the pump outlet. The common reasons are as follows:
1.1.1 If wiring is correct or wrong, the motor may be reversed, so it is necessary to replace the two main lines and change the pump steering.
1.1.2 Whether the motor is faulty: Use a multimeter to measure whether the three-phase resistance value of the motor is normal, whether the three-phase resistance is balanced, and whether the insulation value of the coil to the ground reaches the standard.
1.1.3 Also need to check whether the temperature resistance resistance value of the motor is normal, some brands of pump in the motor cavity is also equipped with a leakage sensor, need to check the resistance value to determine whether the machine seal is damaged, whether the transmission medium into the motor trigger alarm.
1.1.4 By measuring the voltage on the pump whether there is phase deficiency or low voltage.
1.2 Mechanical reasons:
1.2.1 It is necessary to check whether the outlet valve is open and whether the valve is faulty.
1.2.2 Whether the pump is correctly installed on the coupling, whether there is the possibility of virtual connection (it is better to install the pump under the condition of low water level, so that the actual cooperation between the pump and the coupling can be seen), and whether the underwater part of the pipeline is damaged.
1.2.3 Whether there is sludge accumulation at the pump entrance and the possibility of poor sewage entering the water.
1.2.4 Whether the impeller is worn, whether the wear ring of the pump shell is worn, and whether the pump shaft is broken.
1.2.5 Whether the motor bearing is damaged can be measured and judged by the motor current.
1.3 Control Unit Fault:
1.3.1 Control cabinet whether there are electrical components fault, false connection, aging
1.3.2 Whether the liquid level floating ball works normally
2. After the motor is energized, the pump outlet flow pressure fails to meet the requirements. The common reasons are as follows:
2.1 Mechanical reasons
2.1.1 Whether the flow parts are worn, whether the clearance of impeller and mouth ring exceeds the standard.
2.1.2 Whether there are sundries blocking the impeller runner. Whether there is sludge accumulation at inlet.
2.1.3 Whether the pipeline is damaged, especially the underwater part, with poor visibility.
2.2 Electrical reasons
2.2.1 Whether the voltage is normal or not, the star triangle connection method needs to be made clear.