What this RCBO is and where it lands
The Siemens 5SU9353-1KK06 is a 2-pole RCD-operated circuit breaker (RCBO) from the SENTRON family, combining overcurrent protection (C-curve, 6 A) with 30 mA residual-current protection in a single 36 mm-wide (2 MW) module. It is rated for 4.5 kA breaking capacity per EN 60898, overvoltage category III, and mounts in any position on the DIN rail. The 30 mA AC-type trip covers the standard shock-protection threshold for socket-outlet circuits in residential and light commercial panels.
Key ratings and what they mean for fit
The 6 A C-curve overcurrent element trips between 5× and 10× rated current — typical for motor-starter or lighting circuits with moderate inrush. The 30 mA residual-current element is AC-type, meaning it detects sinusoidal AC fault currents only; it does not cover pulsating DC or smooth DC faults (for those, specify type A or F). The 4.5 kA breaking capacity at 230/400 V AC meets the standard domestic and light commercial fault level; if the prospective short-circuit current at the installation point exceeds 4.5 kA, a higher-rated upstream MCB or fuse is needed. The 77 mm depth (70 mm installation depth) fits standard 80 mm-deep distribution boards. The IP20 rating applies only when the distribution board is installed and conductors are connected — the device itself is not sealed for wet environments. Operating temperature range is -40 °C to 75 °C, with 95% humidity tolerance, so it is suitable for unheated enclosures in temperate climates.
Panel integration notes
The device occupies 2 modular width units (36 mm) on a DIN rail. Supply can enter from either the top or bottom. The neutral conductor is switched internally (2-pole switching). Touch protection is built in. Halogen-free and silicon-free construction meets low-smoke, low-toxicity requirements for public-access buildings.