Although deep-well pumps are vertical long-shaft multi-stage centrifugal pumps (or mixed flow pumps), the reasons for their failures are quite different from those of ordinary horizontal pumps. Troubleshooting should be based on the principle of “easy first, then difficult, first uphole and then downhole” to find out the main cause of the failure and eliminate the symptoms.
In this case, the water level of the well should be measured first. If the water level of the well drops too much, it means that the water inflow of the well is less than the designed water output of the pump. As a temporary measure, the outlet of the small pump can be shut down, and for long-term measures, a pump with a smaller flow rate should be replaced.
If the well water level does not drop significantly, it may be that the overflow part is blocked by sand, debris, etc., or the impeller and the deflector shell have been worn out in direct contact. At this time, the pump should be lifted to clean up the dirt, or the impeller should be replaced .
This kind of failure often occurs when a new pump is commissioned or is disabled for a long time for the first time. If the switch is turned on, the fuse is blown immediately, or the motor does not rotate but only buzzes, or the number of rotations is not enough, it is a starting fault. At this time, you should first check whether the motor wiring is proper, and measure the voltage to see whether it is too low. If the wiring is wrong, you should correct the wiring error; if the voltage is low, you must further check whether the power supply voltage is low, or the wire number is small, the transformer capacity is not enough, the transformer is too far away from the unit, etc., check one by one, and take corresponding measures. Measures to be resolved.
If the well pump is started up to the normal number of revolutions, but there is no water output for 1 or 2 minutes, or the water output is suddenly interrupted during normal operation, stop immediately and check again to avoid dry friction and burn out the rubber bearings and impellers, causing vibration or even shaft broken accidents.
4 The power unit of the deep well pump is overloaded during the working process: the main reasons are:
① There is friction between the impeller and the deflector shell, so stop the machine and adjust the gap.
②The ball bearing of the motor is damaged. Stop the machine and replace the bearing.
③Due to incomplete well washing, the water pump is blocked by sediment or stuck by debris. At this time, the water pump should be lifted to clean up the sand or debris, and re-wash the well if necessary.