What it is and where it lands in the panel
The Siemens SENTRON 5SU9306-0KK06 is an RCBO — a combined residual-current device and miniature circuit breaker in one 18 mm wide unit, 1P+N, rated 6 A with a 30 mA residual trip and Type B tripping characteristic. It's built for DIN-rail mounting in distribution boards, and the 18 mm width (one modular unit) means it packs into tight rows without stealing space from adjacent breakers. The 70 mm installation depth and 77 mm overall depth keep it clear of the gland plate in a standard 125 mm tall enclosure.
What the ratings mean for the buyer
The 6 A rated current at 30 °C is the continuous load it can carry in a 30 °C ambient — at 40 °C that derates to 5.64 A, at 50 °C to 5.22 A, and at 55 °C to 4.86 A. So if the panel sits in a hot machine cabinet, size the load accordingly. The 30 mA residual trip covers personnel protection (earth-leakage) for AC circuits, and the Type B characteristic means it trips instantaneously on short-circuit above 3 to 5 times rated current — typical for resistive and small inductive loads like lighting or control transformers. The 6 kA breaking capacity per EN 60898 is the maximum fault current it can safely interrupt; that covers most residential and light commercial service entrances.
Deployment context
This RCBO mounts on DIN rail in any position, with the supply coming from below. The IP20 rating means it's protected against finger contact but not against moisture — it belongs inside a distribution board, not out in a washdown zone. Halogen-free and silicon-free construction matters for environments where outgassing from a fault could contaminate sensitive electronics or cause corrosion in sealed cabinets.