Problemen en oplossingen aangetroffen in werkelijk onderhoud van schakelen voeding voeding:
1. Delta frequentie omvormer (fout fenomeen: no display when powered on)
After testing, it was found that the main circuit of the power supply, charging resistor, and main circuit contactor were all normal, so it was determined that the switch power board was faulty. Follow the above maintenance steps to measure the switch power board. During the first step of measurement, it was found that the 330K Ω/2W voltage drop resistance between the DC bus 560V and the PWM modulation chip was damaged. The nominal resistance of 330K Ω/2W was measured to be above 2M Ω, so the PWM modulation chip could not receive the power to start, so it could not start and work. To be cautious, key components such as switch tubes, transformers, rectifier diodes, and filter capacitors were also tested. After confirming that there were no issues, the power on test was conducted, and it was OK! The switch power supply vibrates, and the output voltage of each group is normal. After installing the frequency converter, the startup test is normal. This frequency converter has been repaired (note: maintenance personnel must develop a habit during maintenance: do not rush to replace the faulty components for testing, be sure to test all high-power and easily damaged components, and try the machine again after confirming that there are no problems, which is both safe and safe).
2. Tai'an frequentie converter (fout fenomeen: no display when powered on)
Na testen, it was found that the main circuit of the power supply, charging resistor, and main circuit contactor were all normal, and the fault was determined to be on the power board. Follow the repair steps to measure the switch power board.
The first step of measurement passed, and during the second step of measurement, it was found that the c-e junction of the switch tube had broken down. It was removed, and then key components such as the transformer, rectificer diode, and filter capacitor were tested. After confirming that there were no problems, the power on test was conducted, and the output voltage of each group was normal. The installatie test was normal, en de fout was geëlimineerd.
3. Siemens frequentie converter (fout fenomeen: no display wanneer ingeschakeld aan)
Na testen, it was found that the main circuit of the power supply, charging resistor, and main circuit contactor were all normal, and the fault was determined to be on the power board. Follow the repair steps to measure the switch power board.
The first step passes the measurement, the second step passes the measurement, the third step passes the measurement, the fourth step passes the measurement, and then the power board is separately powered to measure that the power terminal of the PWM modulation chip has a voltage of about 12.5V to the ground, gising that the power supply is normal. Using an oscilloscope to observe the PWM output terminal of the chip, it was found that there is no PWM modulation waveform. After replaceing the PWM modulation chip, the power on test was normal and the fault was resolved.
4. Schneider frequentie omvormer (fout fenomeen: no display wanneer ingeschakeld aan)
Na herhaaldelijk branden de schakelaar buis % 2c het was gevonden door testen dat het hoofd circuit % 2c opladen weerstand % 2c en hoofd circuit contactor van de stroom voeding waren alle normaal % 2c en de fout was bepaald zijn aan zijn op het aan / aan de macht bord.
The first step passed the measurement, the second step found a breakdown of the switch tube, the third step passed the measurement, and the fourth step passed the measurement. Replace the switch tube with a new one, and separately power on the power board, but the tube burned again. After removing the switch tube, do not install the tube. Conduct a power on test and measure that the power terminal of the PWM modulation chip has a voltage of about 12V to ground, which is also normal. Using an oscilloscope to observe the PWM output terminal of the chip, it was found that the PWM wave was only about 5-6 KHZ. After power outage, the timing component was removed for measurement and it was found that the resistance value of the timing resistor increased. After replacing the timing resistor and switch tube, the power was turned on normally and the power tube was no longer burned. The fault was resolved.
