Grounded AC-DC power supply, what connects to earth ground?
Not sure if this is what you were looking for, but here goes.

Earth ground is attached to the metal chassis, which should be common to all metal chassis parts. It is typically for safety and shielding. The AC ground (green) connection would be tied to earth ground, or chassis ground as its often called. The Ov or negative of the DC can be tied to chassis ground, but not always, depending on the system. 

I work with life safety equipment, and all of our power systems are electrically isolated from earth ground.