Ratings that matter for the panel
The 5SU9304-1KK45: The 45 A rating at 30 °C is the headline number, but out here in a real panel — especially one stacked tight in a warm cabinet — you need the derated figures. At 40 °C it's 42.3 A; at 45 °C (the upper end of its -25 to +45 °C ambient range) it's 40.95 A; at 50 °C it drops to 39.15 A; at 55 °C it's 36.45 A. If your load pulls 40 A continuous and the panel ambient hits 45 °C, this breaker holds. But push the ambient to 55 °C and you're down to 36.45 A — that's a real constraint for a motor circuit that's already borderline. The 10 kA breaking capacity per both EN 60898 and IEC 60947-2 means it can safely interrupt a fault current up to 10 kA at the rated voltage. That's the standard for most commercial and light industrial distribution boards. The energy limiting class is 3, which keeps the let-through energy low enough to protect downstream wiring and devices in a coordinated panel.
Wiring and mounting
This RCBO accepts solid or stranded conductors from 0.75 mm² up to 35 mm² — that covers everything from a 1.5 mm² lighting circuit to a 10 mm² feeder. The supply can come from either top or bottom, which saves headaches when you're landing a busbar or looping through a panel. Installation depth is 70 mm, overall depth 77 mm, and it snaps onto standard DIN rail. Mounting position is any, so horizontal or vertical panels are fine. Touch protection is built in, and the IP20 rating holds once the distribution board is closed with conductors connected.