TM500 high-power compartments
The larger mainframes in the TM500 series usually have one compartment that can take high-power plugins.
A metal cover to the left of the backplane connector pushes a switch in the rear of a high-power plugin in that compartment. In the other, low-power compartments, a hole in the cover prevents this. Smaller mainframes like the TM503 may have no such covers at all.
