I have a 24V Multiplus 5000VA connected to my battery system. I also have a 10KW Generator connected to AC Input.
If I'm using the generator to charge my system and afterwards turn it off, the Multiplus makes a very loud hum/vibration that slowly diffuses after 5 or so seconds. This happens almost every time I turn off the generator. I even programmed the multiplus to stop taking AC Input from the generator before powering it down.
Is this sound part of normal operation when switching off AC Input to the Multiplus?
Edit: Video of what I'm describing