The Siemens SENTRON 5SU9304-6KK06 is a combined residual-current circuit breaker with overcurrent protection — an RCBO — in a single 1-module-width (18 mm) package. It integrates a 6 A overcurrent trip with B characteristic and a 30 mA Type A residual-current device, so one unit handles both short-circuit and earth-fault protection on a final subcircuit. The 10 kA breaking capacity, rated per both EN 60898 and IEC 60947-2, tells you it can safely interrupt fault currents up to that level without welding contacts or cascading damage upstream — a solid fit for domestic and light commercial distribution boards where the prospective short-circuit current stays under that threshold. Rated insulation voltage is 264 V, with a 4 kV surge-voltage withstand (overvoltage category III). Mechanical service life is 10,000 switching cycles typical. This is an active-production part. Sourced and quoted to order against an RFQ through independent distribution.
Fit and mounting
At 18 mm wide (1 modular unit), it snaps onto standard DIN rail and occupies one slot in a consumer unit or distribution board. Depth is 77 mm, installation depth 70 mm — that's the dimension to check against enclosure clearance, especially if gland plates or wiring ducts sit close to the rail. Height is 125 mm. The supply can enter from either top or bottom, which simplifies panel wiring when busbar orientation forces a reverse feed. Mounting position is unrestricted — any orientation works. Ingress protection is IP20, but only when the distribution board is installed with conductors connected — meaning the RCBO itself isn't sealed; the enclosure provides the environmental barrier. This is standard for DIN-rail protective devices; keep it inside a cabinet, not exposed to washdown or outdoor weather.
Trip characteristics and selectivity
The B tripping characteristic (per EN 60898) means the magnetic trip operates at 3 to 5 times rated current — so 18 to 30 A for this 6 A unit. That's the standard curve for resistive and general-purpose loads where inrush is low; it's the most common choice for lighting and socket-outlet circuits in residential and commercial panels. The 30 mA residual-current sensitivity (Type A) detects sinusoidal AC fault currents plus pulsating DC fault currents — the type produced by rectifier circuits in electronics, LED drivers, and single-phase VFDs. Type A is broader than Type AC and is now the minimum required by many national wiring regulations for circuits with electronic loads. Energy limitation class 3 means it limits let-through energy to the lowest category per EN 60898 — good downstream protection for wiring and connected equipment during a short-circuit event.
Environmental and compliance
Ambient temperature range is -40 °C to +75 °C, so it handles installation in unheated enclosures or hot machine cabinets. Humidity tolerance up to 95% is stated. Degree of pollution 2 (normally only non-conductive pollution occurs) is typical for protected indoor environments. Designated as an instantaneous RCD-operated circuit breaker — no intentional time delay on the residual-current function, so it trips quickly on earth faults. The test circuit requires a minimum of 115 V AC to operate the test button, which is standard for 230 V systems.