In the field of industrial automation, frequency converter as the core of the drive equipment, its normal operation for the stable operation of the production line is very important. However, as a kind of complex electronic equipment, frequency converter often encounter various faults. This paper will focus on the frequency converter power-on non-response and the frequency converter power-on non-display fault detection and maintenance.
First of all, when the inverter is powered up and does not respond, how should we carry out the overhaul?
The first step, check the power switch power situation. If there is a problem with the power switch, it may cause the inverter not to start properly. At this point, you can change the power switch to solve this problem.
The second step is static testing. Use a multimeter to check the resistance of the inverter to determine if there is an exception. If the test results are normal, proceed to the next dynamic test.
The third stepdo dynamic testing. Start the inverter under no-load condition, and check the output voltage of U, V, W three-phase. If there is a lack of phase, three-phase imbalance and other problems, it may be module or drive board parts such as failure. If the output voltage is normal, carry out a load test, preferably a full load test.
In addition to the problem of no response after electrification, no display on electrification is also a common fault. This usually occurs in the contactor, Inverter Control Panel and to the control panel power supply module three parts.
For the frequency converter on-line no-display fault detection and solutions are as follows:
First, check that the contactor is working properly. If the contactor is damaged, a new one is required.
Second, if there is no problem with the contactor, then further check the power module is working properly. If the inverter high-voltage power supply LED lights, high-voltage DC power supply is normal. If the LED is not lit, the step-down resistor between the high-voltage DC terminal and the primary terminal of the pulse transformer may be damaged and open, requiring replacement of the step-down resistor.
In addition, if the LED indicator on the Main Control Board of the inverter is also bright, indicating that the converter switching power supply is normal, the main board and the main control board DC voltage display is normal. At this point, you can use an oscilloscope to check whether there is a master panel output signal. If there is no output signal, it may be one of the chips HC245 damage, need to replace the HC245 chip.
In the process of repair may also encounter some special circumstances, such as power trip or inverter main power terminal spark. This may be due to damage to the rectifier or a short circuit in the intermediate circuit. At this time, we need to check the input terminals and intermediate circuit dc-side Terminals P, N voltage value, determine the fault causes and take appropriate measures to repair.
In addition, the frequency converter on-line operation without output is also a common problem. This may be due to the frequency converter startup parameters set wrong or the operation of the terminal wiring errors caused. At this point, the need to disconnect the output motor line to restart the inverter, and observe the panel display of the input frequency and measuring the AC output terminal. If the problem persists, it may be that the inverter part is damaged or the motor is not connected to the inverter correctly, requiring further inspection and repair.
To sum up, the fault detection and maintenance of the inverter requires a certain degree of professional knowledge and skills. In actual operation, it is recommended that the professional personnel carry out the overhaul work, so as to avoid unnecessary losses or safety accidents. At the same time, the frequency converter regular maintenance and maintenance is to ensure the normal operation of one of the important measures.
Source: internet (for study only, intrusion and deletion)
