The VFD came with a good manual regardless of chinese reputation, I probably failed to read that passage. Actually I just bought what I'm pretty sure is a breaker. In Italian we call them "interruttori magnetotermici" which translated in English is "magnetothermal; I think is what you call "breaker".

Actually I have repeated this process of unplugging the VFD many times so if this is really a source of problem it may be the culprit for the fail.

Thanks for the hint.