First, static test

 

Set the multimeter to the resistance X10 level, connect the multimeter's red meter stick to the P terminal of the DC power supply inside the inverter, and then connect the black meter stick to R, S, T respectively. The resistance value should be about tens of ohms. When the black watch rod is connected to the end and the red watch rod is connected to R, S, T in order, there will be a resistance value close to infinity. Connect the multimeter's red meter stick to the N terminal of the DC power supply inside the inverter and repeat the above steps. If the result is the same as above, it means that the static test is normal. If the three-phase resistance is unbalanced, it can indicate that the rectifier bridge is faulty. When the red watch rod is connected to the P terminal, the resistance is infinite, and it can be concluded that the rectifier bridge is faulty or the starting resistance is faulty.

 

 

Two, dynamic test

 

动态 The dynamic test can be performed after the static test. Before power-on, you must confirm whether the input voltage is correct. If you connect the 380V power supply to the 220V-class inverter, there will be explosives (explosive capacitors, varistor, modules, etc.). It is necessary to check whether the broadcasting ports of the inverter are correctly connected, whether the connection is loose, and the abnormal connection may sometimes cause the inverter to malfunction, and in severe cases, an explosion will occur. Detect the fault display content after power-on, and preliminarily determine the fault and its cause. If the fault is not displayed, first check whether the parameters are abnormal, and reset the parameters, then start the inverter with no load (without motor), and test the three-phase output voltage values ​​of U, V, and W. If there is a lack of phase or three-phase imbalance, the module or driver board is faulty. When the output voltage is normal (no lack of phase, three-phase balance), load test is performed. When testing, it is best to test at full load.