RCBO for final-circuit protection
The Siemens 5SU1354-0KK16 is a 1P+N RCBO (residual-current circuit breaker with overcurrent protection) from the SENTRON series, combining a Type B miniature circuit breaker and a residual-current device in a single 2-module-wide (36 mm) housing. Rated 16 A at 30 °C with a 10 kA breaking capacity per EN 60898, it protects against overload, short-circuit, and earth leakage in a single DIN-rail footprint — saving a module over separate MCB+RCCD stacks.
What the ratings mean for fit
Type B tripping characteristic (3–5× In magnetic release) suits residential and light commercial final circuits where inrush from lighting or small electronics is moderate — not motor or transformer loads that need Type C or D. The 10 kA rated short-circuit capacity per EN 60898 covers most domestic and commercial service-entrance fault levels; the 20 kA rating per IEC 60947-2 gives headroom for industrial panel coordination studies. Current rating is temperature-dependent: 16 A at 30 °C, derated to 15.2 A at 40 °C, 14.4 A at 50 °C, and 12.32 A at 70 °C. In a warm enclosure (40–50 °C typical for a loaded panel), expect to apply the 40 °C or 50 °C column for continuous load sizing — not the 30 °C headline figure. The 1P+N design switches the line conductor only; the neutral is switched internally for isolation but not protected against overcurrent. That matches single-phase final circuits where the neutral is not overloaded. Rated insulation voltage 264 V, overvoltage category III, pollution degree 2 — standard for fixed-installation distribution boards. Mounting position any, supply feed from top or bottom — flexible for panel layout. Depth 77 mm (installation depth 70 mm) fits standard distribution boards; the 36 mm width (2 modular units) occupies one slot on a DIN rail alongside other SENTRON devices.