Off-line maintenance means that after loosening the main power supply circuit of soft starter, Mitsubishi Inverter Fault Learning Training in Taiyuan, Shanxi Province, maintains the switching power supply/driver board independently. After maintenance, it is determined that all the common faults of the driver board are cleared and then operated on the computer to ensure the safety of IGBT. First, look at a data test table. Today, Shandong Inverter Maintenance Company and everyone work together. Look at some fault phenomena and treatment methods of frequency converter switching power supply.
1. By using digital multimeter, the statistical data in Table 4-3 can be calculated. The AC current gear of the pointer multimeter can also display a slightly larger AC voltage value of the information. Therefore, when the power is off, the information must still display the working voltage value. But in the start-up situation, the pen immediately indicates the opposite direction - indicating that the AC current gear of the pointer multimeter can measure the peak value of the signal voltage, but it can still indicate the polarity of the voltage.
2. When the driving power supply voltage is 15V and -7V, the voltage value of the output side detected also decreases accordingly.
3. Because of the discreteness of power circuit and electronic devices, the difference of maintenance and training of Inviden Inverter in driving power supply voltage from all walks of life, and the difference of single pulse waveform of PWM (SPWM) soft starter of different types and specifications, the dynamic working voltage value calculated by accurate measurement will also vary greatly. If the AC current value is measured from the open terminal, its peak value is usually close to the supply voltage value. Generally, as long as the IGBT is above 13V, it can work reliably, and the amplitude of the six-way pulse voltage is different. Therefore, even if the same type of converter uses the same driver IC of different models, it is impossible to measure the same results. We need not pay too much attention to the accuracy of the numerical value. We can judge the working state of the driving circuit from the obvious changes of the passive, static voltage and voltage polarity.
In each path, the optocoupler circuit can immediately check the input data signal from the two input pins of the driver IC and the output data signal from the output terminal of the driver data signal (the control module opens the terminal).
If the input signal voltage is zero, the signal transmission circuit from CPU to driving IC is detected forward. For the detection content, see Chapter 7 of Huichuan Inverter Maintenance Training Chapter. If there are input signals, the output signal terminals of CN1 and CN22 may be as follows:
1)用50V沟通交流档测PC923的6脚工作电压，若过低(如仅为10V)，三菱变频器故障全集比照精确测量一下下PC929 的键入2、 3脚工作电压，若稍低，则往前检测从至驱动忆的信号传输电路。
1) Measure the 6-foot working voltage of PC92 3 with 50V communication AC file. If it is too low (for example, only 10V), Mitsubishi Inverter Fault Complete Measure the input 2 and 3-foot working voltage of PC929 accurately. If it is slightly low, the signal transmission circuit from PC 929 to driving memory will be detected forward.