Variable Frequency Drive fault judgment

How to judge the fault of the Variable Frequency Drive?

1. The rectifier module is damaged
Usually caused by grid voltage or internal short circuit. Replace the rectifier bridge after eliminating the internal short circuit. When dealing with faults on site, focus on checking the user grid conditions, such as grid voltage, whether there are electric welding machines and other equipment that pollute the grid.

2. The Frequency Inverter module is damaged
Usually caused by damaged motor or cable and faulty drive circuit. After repairing the drive circuit, check that the drive waveform is in good condition and replace the module. After replacing the drive board in field service, the motor and connecting cables must be checked carefully. The inverter can only be run after it is determined that there is no fault.

3. No display when power on
It is usually caused by the damage of the switching power supply or the damage of the soft charging circuit, so that there is no direct current in the DC circuit, such as damage to the starting resistance and damage to the operation panel.

4. Display over-voltage or under-voltage
Usually due to input phase loss, circuit aging and circuit board moisture. The solution is to find out its voltage detection circuit and detection point, and replace the damaged device.

5. Display overcurrent or grounding short circuit
Usually due to damage to the current sense circuit. Such as Hall elements, op amp circuits, etc.

6. The power supply and driver board start to display overcurrent
Usually caused by damage to the drive circuit or inverter module.

7. The no-load output voltage is normal, and the overload or over-current is displayed after loading.
It is usually caused by improper parameter setting or the aging of the drive circuit and the damage of the module.

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