What is the fault of the inverter not responding after power on?

Generally speaking, if the inverter fails, the corresponding fault code will be displayed. So what is the reason for the inverter not responding after the failure? How to troubleshoot?

01 Troubleshooting method

1. Check the power switch: 

First confirm the power-on status of the power switch. If there is a problem with the power switch, the inverter will not start normally. We Just need to replace the switch。

2. Static test: 

Use a multimeter to detect the resistance value of the inverter. Adjust the multimeter to the resistance multiply by 10 levels. Connect the red pen to the P terminal of the inverter, and the black pen to R,S,T in turn. The measured result is about dozens of Ohms of resistance and is basically balanced. Next, exchange, connect the black pen to the P terminal, and the red pen to R, S, T in turn. The measured result will be a resistance value close to infinity. Then connect the red pen to the N terminal and repeat the above process. If the result is the same, the static test is normal.

3. Dynamic test: 

Start the inverter under no-load conditions and observe the three-phase output voltage of U, V, W. Check whether there are problems such as phase loss and three-phase imbalance. If there is an exception,it may be a fault of the module or driver board. If the output voltage is normal, further load testing is required.

02 Solution

1. Power failure: Check whether the power supply is normal and ensure that the power supply can be connected.

2. Parameter setting error: Check the parameter setting of the inverter to see if it matches the motor.

3. External control signal problem: Confirm whether the external control signal is normal, such as whether the PLC or other control equipment is normal.

4. Module or driver board failure: Phase loss and three-phase imbalance may occur during dynamic testing, which are all module or driver board failures.