Fault determination of danfoss frequency converter

Fault determination of danfoss frequency converter

1. Danfoss inverter maintenance static test

1. Test the rectifier circuit

Find the p-end and n-end of the dc power supply of danvers inverter, and adjust the multimeter to resistance X10. The red meter bar is connected to P, and the black meter bar is connected to R, S and T respectively. It should have resistance value of about dozens of ohms and be basically balanced. Instead, connect the black bar to the P end, and the red bar to R, S, T, in turn, with a resistance close to infinity. Connect the red bar to the N end and repeat the above steps. You should get the same result. If there are the following results, it can be judged that the circuit has been abnormal, A. Resistance value three-phase imbalance, it can be explained that the rectifier bridge fault. B. When the red meter bar is connected to the p-end, the resistance is infinite, and it can be concluded that the rectifier bridge or the starting resistance has a fault.

2. Test the inverter circuit

Connect the red meter bar to the P end and the black meter bar to U, V and W respectively. There should be resistance values of several tens of ohms, and the resistance values of each phase are basically the same. The inverse phase should be infinite. Connect the black table bar to the N end, repeat the above steps to get the same result, otherwise you can determine the failure of the inverter module.

Two, danfoss inverter maintenance dynamic test

After the static test results are normal, the dynamic test can be carried out, that is, the electrical trial. The following points should be noted before and after power on:

1. Before power on, please confirm whether the input voltage is wrong. If the 380V power supply is connected to the 220V class danfoss frequency converter, there will be a blasting machine (blasting capacitor, varistor, module, etc.).

2. Check whether the connection ports of danfoss frequency converter have been connected correctly, and whether the connection is loose. Abnormal connection may sometimes lead to the failure of danfoss frequency converter, and in serious cases, the machine will explode.

3. Detect the fault display content after power on, and preliminarily determine the fault and its cause.

4. If no fault is shown, first check whether the parameters are abnormal. After the parameters are restored, start the danfoss inverter under no load (without motor connection), and test the three-phase output voltage of U, V and W. If there is a phase loss or three-phase imbalance, the module or the drive plate will fail.

5, under the condition of normal output voltage (no phase, three-phase balance), test on load. When you're testing, you're testing at full load.