The ABB F204AC-25/0.1 is a 4-pole residual current device (RCD) from the F200 Series, rated at 25 A with a 100 mA rated residual current, designed for 480Y/277V AC systems and listed under UL 1053. The 25 A rating means it carries the full load current of a 25 A circuit; the 100 mA residual sensitivity is higher than the typical 30 mA for personnel protection — this unit is sized for equipment or fire protection where nuisance tripping from normal leakage on longer runs would be a problem.
Panel integration
Mounts on standard DIN rail, which means it snaps into the same enclosure footprint as other modular DIN-rail devices — no extra drilling or sub-panel. The 4-pole width (roughly 4 modules) should be factored into the DIN-rail fill count during panel layout.