Inverter: After decades of development, the quality of the inverter is relatively stable and reliable. In the past, household inverters were more prone to problems, and now the possibility of failure is not high. However, after using any product for a period of time, it is easy to have problems. When a problem occurs, it is crucial to determine whether it is the inverter itself or the peripheral circuit.

Inverter fault code is important

If the inverter itself fails, a fault code will usually be displayed. Common ones are overcurrent, overload, overvoltage, undervoltage, ground fault, and output fault alarms. It is more purposeful to find the problem according to the content of these alarms. , The fault code display of each type of inverter will be different, but the content is roughly the same. It is usually necessary to query the fault table of the manual according to the code displayed on the panel and deal with the meaning of the fault code.

You can turn off the power first, wait until the power of the capacitor is almost exhausted (equivalent to the mainboard power off), and then turn on the power. At this time, check whether there is a fault code. If there is no fault code, it is usually caused by poor contact or excessive load. If any changes are caused by changes, it can usually be proved to be an internal problem of the inverter. Of course, this is only an approximation and cannot be said to be correct. The actual situation is more complicated and requires further diagnosis on the spot.

For example, if there is an overcurrent, you can cut off the power supply at this time and then turn it on again. If it is still overcurrent, you can disconnect the connection line between the inverter and the motor at this time, and then power it on again to see if there is an overcurrent code. Moreover, the general explanation is an internal problem. If the fault disappears, it is usually caused by an external problem, such as poor insulation of the cable or motor. At this time, you can find an insulation meter to measure the insulation resistance of the motor and cable respectively to see if it is less than 5 megohms. If so, you need to repair the motor separately or replace the cable.

If it is an internal problem of the inverter, such as alarms such as overcurrent and grounding, it is usually because the IGBT module is faulty. You only need to use a multimeter to measure the main circuit to determine whether there is a short circuit. Of course, it appears more on the driver board. The optical coupler and the resistance container are damaged. These repairs require a certain degree of electronic knowledge. You can ask some industrial control maintenance companies for help.

Output phase loss is usually three-phase unbalanced. In addition, disconnect the connection between the inverter and the motor and check them separately. The imbalance of the motor can be judged by simply measuring the resistance with a multimeter.

In many cases, undervoltage, etc. is caused by long-term use of the inverter and aging and insufficient capacity of the capacitor. You can find the same specifications to replace it.

Overvoltage is usually caused by problems such as high grid voltage, too short acceleration/deceleration time or heavy load.

If misalignment such as ERR occurs and cannot be reset after power off and power on, it is a mainboard type failure and the mainboard needs to be replaced.

If no information is displayed, it is usually caused by a burnt switching power supply or abnormal power supply.