Multimeter to detect submersible pump line fault
The circuit fault of the submersible pump includes open circuit (that is, there is no connection between the lines), and there is leakage (the insulation layer of the enameled wire is damaged or the coil is grounded)
How to troubleshoot the line fault? For open circuit, we can use the multimeter to adjust to Fengming level, that is, the diode level to measure the resistance value of each group of coils. Generally, the resistance values of the three submersible pumps are close to each other. If there is no Resistance, that is, the coil is blocked, that is, the circuit is broken.
There is another kind of leakage. For this fault, we need to use a meter. The meter has two wires. We connect one to any set of coils and the other to the iron sheet, and then turn the handle of the meter to see The direction of the pointer on the screen swings, if the pointer swings to 500, it means that the coil is not leaking, which is normal. If it swings to 0, it means that the coil is leaking, and it needs repairing.
By using the method of shaking the meter to measure the resistance of each of the three sets of coils and the ground, it is possible to judge whether the line is good or bad.
In addition, when the submersible pump is lifted out of the water, it is necessary to check whether the pump body is bumped or damaged. Whether the gasket is damaged. If there is a problem, it should be replaced immediately to avoid secondary damage caused by water entering the pump body after launching.
If it is to check the circuit, then start from the main circuit, and then check the control circuit, it needs to be repaired according to the drawings.
If you want to check the fault of the water pump itself, it is not enough to rely on a multimeter alone. The multimeter can measure the resistance of the water pump motor winding, but because the voltage of the multimeter itself is very low, it cannot accurately measure whether the insulation of the water pump motor is qualified. For For submersible pumps, insulation damage should be a common failure.
To check the insulation of the motor, a low-voltage shaker meter with an insulation rating of 500 volts is required. Connect one end of the megger to the shell of the water pump, and the other end to the three windings of the motor (the three windings need to be short-circuited together in advance), and then shake the handle of the megger at a speed of 120 revolutions per minute. If the measurement If the value is less than the normal value, it means that the motor insulation of the pump has been damaged and can no longer be used.
