What this RCBO is and where it fits
The Siemens 5SU1354-6KK13 is a SENTRON RCBO — residual current circuit breaker with overcurrent protection — in a 1P+N, 2-pole package. It protects a single-phase final subcircuit against earth leakage and overload/short-circuit in one DIN-rail module. The B curve (3–5× In magnetic trip) makes it the standard choice for resistive and general-purpose loads in domestic and light commercial distribution boards: lighting, socket circuits, small appliances. Rated 13 A at 30 °C ambient, it carries a 10 kA breaking capacity per EN 60898 and 20 kA per IEC 60947-2, so it can clear faults up to those levels without upstream coordination failure.
Temperature derating — the real continuous current
The 13 A rating is at 30 °C. Inside a warm enclosure the available current drops: 12.48 A at 40 °C, 11.96 A at 50 °C, 11.31 A at 60 °C, and 10.01 A at 70 °C. If your panel runs at 50 °C ambient, size the downstream load for 11.96 A continuous, not the label 13 A. The part is halogen-free and silicon-free, which matters for clean-room or corrosive-environment installations where outgassing contaminates contacts or optics.
Panel integration — DIN-rail fit and wiring
Occupies 2 modular width units (36 mm wide) on a standard DIN rail. Depth is 77 mm; installation depth behind the panel face is 70 mm. Mounting position is unrestricted — any orientation works. Supply can enter from top or bottom, which simplifies busbar routing in crowded enclosures. The IP20 rating applies once the distribution board is installed with conductors connected; it is not a standalone outdoor rating. Overvoltage category III and pollution degree 2 suit fixed-installation mains distribution.
Breaking capacity and selectivity
Two breaking-capacity ratings: 10 kA per EN 60898 (the standard for MCBs in household installations) and 20 kA per IEC 60947-2 (the industrial standard for circuit breakers). The higher 20 kA figure means this RCBO can be applied in industrial sub-distribution where fault currents reach 20 kA, provided the upstream device coordinates. The 4 kV rated surge voltage resistance (impulse withstand) covers typical mains transients in TN and TT systems. Energy limitation class 3 means it limits let-through energy effectively, reducing stress on downstream wiring.