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The following is an example of how to deal with common faults of submersible electric pumps.
1. The electric pump cannot be started or is difficult to start
(1) Fault phenomenon, the electric pump cannot be started after the power switch is turned on: or after the motor is started, the speed cannot go up, the water pump does not produce water or the water output is small.
(2) Inspection and analysis When this happens, inspection and analysis can be carried out from both electrical and mechanical aspects.
1) The current is very large and the motor will overheat, which can be solved by checking and adjusting the voltage of the transformer.
① If the capacity of the transformer is too small, it will be difficult to start the motor. It can be replaced with a transformer of suitable capacity.
②The cross-section of the power supply line is too small and the line is too long, resulting in too much voltage drop of the line, which makes it difficult for the motor to start. The line with a larger cross-section should be used, or the line should be close to the transformer.
③The motor is powered by two phases, and there is no current in one phase, and the motor cannot be started. Clamp-on ammeter can be used to check the three-phase current, or observe the ammeter on the control cabinet. The input is two-phase power supply. Because the power is cut off immediately, check whether the power switch is in good contact and whether the main circuit wiring is broken
Or loose, whether the fuse is blown out.
④If there is no problem with the above, then check whether the power cable has a phase break, whether the cable joint is good, and whether the motor winding is burned out. Find out the cause and remove the fault.
2) Mechanical aspects. The three-phase current of the motor is uniform, the current is large and balanced, and the motor cannot start, the reason should be found from the mechanical aspect. The bearings of the motor and the water pump cover the shaft, the impeller is stuck, and the water pump or the motor enters the foreign matter, etc., all of which will make the motor unable to start. dismantle
Start the pump to check, troubleshoot or repair it.
2. The electric pump does not output water or the water output is small
① Trouble phenomenon After the electric pump is started, the three-phase current of the motor is normal, the power supply voltage is no problem, the water pump does not produce water or the water output is small. 2. Check and analyze
1) When the newly installed electric pump is commissioned, the water pump does not output or the water output is small. It may be that the rotation direction of the water pump is reversed. Change the phase sequence of any two-phase cable to solve the problem: or Yang Cheng exceeds it, and replace it with a larger electric pump: In addition, the connection flange of the lift pipe leaks, and the rupture of the lift pipe will affect the water.
Pump water volume.
2) When the electric pump is used normally, the water output is gradually decreasing. It may be that the sealing ring of the electric pump is severely worn after long-term use. It should be replaced: the suction port of the water pump is blocked, which affects the suction of water. Clean the grid or filter of the water pump.
3) Broken bars of the cast aluminum rotor of the motor, and open welding of the end ring of the copper bar rotor, resulting in insufficient output power of the motor, lower speed, and insufficient water output of the water pump. The rotor should be replaced or welded.
4) The motor runs normally, but the three-phase current is small, and the water pump does not deliver water. It may be that the shaft of the water pump is broken, the coupling of the pump is loose, etc., should be overhauled, the shaft should be replaced or the electric pump should be reassembled.