First, an explosion will occur if the input power supply and the output motor are connected in reverse.
Second, there are two possible reasons for the inverter explosion:
1. Capacitor explosion;
2. An explosion occurred inside the frequency converter due to a short circuit. The first reason is usually that the internal temperature of the frequency converter is too high, causing the capacitor to explode. The second reason depends on the operating environment (if the environment is too harsh, an explosion-proof frequency converter should be considered), or there may be foreign objects left inside the frequency converter.
3. Causes of capacitor explosion;
1. Power supply voltage is too high
2. Capacitor failure or leakage. This is likely due to excessive room humidity or the presence of water droplets inside the inverter, causing a short circuit in a component and leading to an explosion. For older machines, another possible cause is the lack of insulation on the inverter's circuit board. Older Omron inverters often lack this insulation and corrosion protection on their circuit boards, which can also lead to explosions.
3. If the IGBT module explodes immediately after the inverter is powered on, and the inverter is not in operation, ruling out power wiring errors, it's almost certain that the IGBT mis-conduction caused a P/N short circuit. There are many possible causes, including issues with the switching power supply, drive circuitry, etc. There could be a short circuit, a problem with the drive circuit board, or the trigger signal not being connected to the module. It could also be a case of a low-voltage wire carrying a high-voltage current. Another possibility is a foreign object conducting electricity, causing a short circuit. Additionally, there could be excessive voltage or aging components.
