Comment by blablabla123

I'm no expert but to my knowledge metal cases always need to be grounded. Which is what I did with my 10" rack. I just bought a socket with a ground connector from an online store, although I'd be curious which exact cable is best practice. I don't have many things connected there anyway and the power supplies are outside of the rack.

FWIW the topic is quite a rabbit hole and for non-mobile metal cases (e.g. screwed on the wall) technically even an electrician seems to be needed.