The Siemens 5SU1324-7FN15 is a SENTRON RCBO — a combined residual-current and miniature circuit breaker in a 2-pole, 2-module-width (36 mm) package. Rated 15 A at 30 °C with a C-curve tripping characteristic, it handles the inrush of motor starters, contactor coils, and small transformers without nuisance trips. Breaking capacity sits at 10 kA per EN 60898 and 15 kA per IEC 60947-2, giving it headroom for most commercial and light-industrial distribution boards where the prospective fault current stays under those limits.
Ratings and what they mean for fit
The C-curve (tripping between 5× and 10× In) is the standard choice for circuits feeding inductive loads — think contactors, small motors, or banks of LED drivers with capacitive input filters. At 15 A nominal, this RCBO protects a final subcircuit up to roughly 3.5 kW on a 230/240 V single-phase supply. The 10 kA breaking capacity under EN 60898 covers the majority of domestic and commercial panel applications; the 15 kA rating under IEC 60947-2 adds margin for industrial sub-distribution boards with higher fault levels. Overvoltage category III and pollution degree 3 mean it's rated for fixed-installation use inside a distribution board, not for outdoor or wet locations. Temperature derating is published: 14.25 A at 40 °C, 13.88 A at 45 °C, 13.41 A at 50 °C, 13.03 A at 55 °C, and 12.56 A at 60 °C. If the panel ambient runs hot — say next to a transformer or in a non-ventilated enclosure — size the upstream protective device for the derated figure, not the 30 °C nameplate.
Panel integration notes
Width of 36 mm (2 modular units) fits standard DIN-rail enclosures. Depth of 72 mm and installation depth of 70 mm leave clearance for a 70 mm deep distribution board. Supply can enter from either top or bottom — no fixed orientation, which simplifies wiring in tight panels. The IP20 rating applies only when the distribution board is installed with connected conductors; the device itself is not sealed against dust ingress before panel mounting. Ambient operating range spans -40 °C to 70 °C, so it can sit in unconditioned electrical rooms or outdoor-rated cabinets.