The Siemens 5SU1354-6KK16 is a SENTRON RCBO — a combined residual-current and miniature circuit breaker — in a 1P+N configuration, meaning it protects one live conductor and switches the neutral. Rated 16 A at 30 °C with a B-curve tripping characteristic, it opens instantaneously on short-circuit between 3 and 5 times rated current, which suits resistive and general-purpose loads where nuisance tripping from inrush is not a concern. Breaking capacity is 10 kA per EN 60898 and 20 kA per IEC 60947-2, so it safely interrupts faults up to those levels without upstream damage. The higher IEC figure gives headroom for industrial panels where the prospective short-circuit current may exceed the domestic standard. Operating frequency is 50 Hz only — not 50/60 Hz — so verify the supply matches before specifying. Mounting position is any, and the supply can feed from either top or bottom, which simplifies panel wiring.
Temperature derating matters for panel fit
The 16 A rating holds only at 30 °C ambient. At 40 °C it derates to 15.2 A, at 50 °C to 14.4 A, and at 60 °C to 13.6 A. At 70 °C it drops to 12.32 A. If the panel runs warm — common in a crowded DIN-rail enclosure — size the RCBO for the actual ambient, not the 30 °C headline number. The device occupies 2 modular width units (36 mm total) on the DIN rail, with an installation depth of 70 mm plus clearance for connected conductors. IP20 protection applies only when mounted in a distribution board with conductors connected — the front face is touch-safe, but the terminals are not sealed against dust ingress.