At 40 °C it derates to 29.1 A, at 45 °C to 27.8 A, at 50 °C to 26.6 A, and at 55 °C to 25 A — so if the panel runs hot, size up accordingly. If the downstream equipment includes VFDs, LED drivers, or rectifiers, a type A or B RCD would be needed instead.
The 5SU9326-1CN32 snaps onto a DIN rail, occupies 4 width units (72 mm), and has an installation depth of 70 mm plus the device depth of 77 mm. The supply can enter from the top or bottom, which helps when the busbar arrangement in the panel dictates the feed direction. Mounting position is any orientation.