Thread: Doepfer A-100PMS12 case
The power coming out of your wall outlet is 15A @ 120V, this equates to 1800W, the (whole order of magnitude) voltage difference being the thing you are missing.
The power you are pulling from the wall at THE VERY max from that case is something like 300W, and that's at absolute max (and there is no way you can come close to pulling like a quarter of that 5V margin)
You would have a very, VERY hard time maxing out a breaker circuit with a Eurorack setup.