I was checking a faulty Schneider VFD (ATV312H037N4) which is rated for a nominal output current of 1.5 A. Turns out the rectifier bridge of the inverter module (FP10R12YT3) blew up and after reading the datasheet I was surprised to find out that the IGBTs are rated for a nominal current of 10 A and the rectifier diodes are rated for 1600 V and 25 A. After checking some other drives from different brands I noticed the same thing.
I get that oversizing of components is normal for this kind of application but this seems a little extreme. Why would they do this? What's keeping this VFD from running a much larger motor that's closer to the ratings of the inverter module?
All the heavy lifting is done by the module so I don't see the reason to why the VFD is rated so low.