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 energy limiting class is 3, which keeps the let-through energy low enough to protect downstream wiring and devices in a coordinated panel.
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. Mounting position is any, so horizontal or vertical panels are fine.