Inverter is now widely used in the industrial control system, and then in the process of use, there will be some fault problems, then what are the common fault problems?
1 、 test rectifier circuit
Find the results, judging circuit has been abnormal, A. internal to the inverter DC power supply P and N terminal, the multimeter resistance to X10 files, the red bar is connected to the P, the black bar according to the R, S, T, normal when dozens of European resistance, and basic balance. Instead, the black bar is attached to the P end, and the red bar is successively connected to R, S, and T, with a resistance value approaching infinity. The red bar is attached to the N end, and the same result should be obtained after repeating the above procedure. If there is a three-phase imbalance in the resistance value, indicating that the rectifier bridge is defective and the.B. red rod is connected to the P terminal, the resistance is infinite, and the fault of the rectifier bridge or the starting resistance can be judged to be out of order.
2 、 test the inverter circuit
The red watch rod is connected to the P end, and the black watch bar is connected with U, V and W respectively. There should be dozens of Ohm's resistance values, and each phase resistance is basically the same, and the reverse phase should be infinite. The black table bar N end, repeat the above steps should be the same result, otherwise it can be confirmed that the inverter module is faulty.
After the position test results are normal, dynamic test can be carried out, that is, the electric test machine. You must pay attention to the following points before and after power up:
1, before power up, must confirm the input voltage is wrong, the 380V power supply into the 220V inverter, will appear in the deep fried machine (fried capacitor, varistors, modules, etc.);
2, check the frequency converter each socket is properly connected, whether the connection is loose, abnormal connection, and sometimes may cause frequency converter failure, serious when the machine and so on;
3, after power up, detect the fault display content, and preliminary determine the cause of the fault;
4, if the failure does not show, first check whether the parameters are abnormal, and after the parameter reset, in the no-load (not connected to the motor) start-up frequency converter, and test the U, V, W three-phase output voltage value. In case of lack of phase and imbalance of three-phase, the module or drive plate is out of order;
5, in the normal output voltage (no phase, three phase balance), the load test, as far as possible full load test.