Noisy (Buzzing) Main Service Panel

I just inspected a home this morning with a fairly noisy main service panel. You can hear the buzzing with the door closed. I’ve spoken with an electrician before who told me that “buzzing” shouldn’t be an issue, but does anyone know how much “buzzing” is acceptable, if any at all? Thanks for your input. The panel was only 3 years old, professionally installed, and otherwise neat and clean. Thanks!

I have found that a couple of times around in my neck of the woods. At that point, I pull out the laser thermometer and try to determine if there is abnormal heating in the panel at the breakers. Some AFCI breakers have been faulty at times and have been over heating. I have had electricians tell me the same thing about not being a problem, others have said different. I will wait and see what anyone else says. In my other line of work, I am a licensed aviation electrician/avionics tech and am still learning about house wiring systems.