What this RCBO is and what it does
The Siemens 5SU1353-1WM10 is a SENTRON RCBO — a combined residual-current device and miniature circuit breaker in one 2-module-wide unit. It protects a single-phase final subcircuit against both overload/short-circuit (10 A, C-curve) and earth leakage (30 mA, type AC). The C-curve trips between 5 and 10 times rated current, so it handles moderate inrush from small motors or capacitive loads without nuisance trips. The 30 mA residual-current element catches line-to-ground faults that could cause electric shock or fire. Rated 4.5 kA breaking capacity per EN 60898, with a higher 15 kA rating per IEC 60947-2 for industrial coordination. The 1P+N configuration switches the phase and disconnects the neutral, so the neutral is opened when the device trips — important for isolating the circuit completely. It accepts supply from either top or bottom, which simplifies panel wiring. Touch protection is built in, and the housing is halogen-free and silicon-free, meeting clean-environment requirements for semiconductor or medical-adjacent installations.
Mounting and panel fit
Snaps onto standard 35 mm DIN rail. Installation depth is 70 mm, and it occupies 2 width units (36 mm). Mounting position is any — horizontal, vertical, or flat — so it fits tight enclosures. The IP20 rating applies only when the distribution board is installed and conductors are connected; it's not a standalone outdoor device. Overvoltage category III and pollution degree 2 suit it for fixed installations in building or industrial distribution boards. Mechanical service life is 10 000 switching cycles typical. The device withstands surge currents up to 1 kA (8/20 μs waveform), which covers most indirect lightning or switching transients in a building installation. Ambient temperature range is -40 °C to 75 °C, with max 95% humidity — wide enough for unheated plant rooms or outdoor enclosures in temperate climates.