The 5SU1656-1KK25: Rated breaking capacity is 6 kA per EN 60898 and 15 kA per IEC 60947-2. The higher IEC figure matters when the RCBO sits in an industrial panel with upstream fault current potential above 6 kA — the 15 kA rating gives headroom for selective coordination without cascading upstream.
Temperature derating — what the 25 A rating actually delivers
At 40 °C it derates to 23.5 A, at 50 °C to 21.75 A, and at 70 °C to 18.25 A. For a panel running warm — say 45 °C internal — the usable continuous current is 22.75 A, not the nameplate 25 A. Factor this into the load calculation.
Mounting and installation notes
IP20 applies once the distribution board is installed with conductors connected. Touch protection is built in.