What this RCBO is and what it protects
The Siemens SENTRON 5SU9304-0KK06 is a combined residual-current circuit breaker with overcurrent protection (RCBO) in a single 1 MW modular-width unit. It integrates a 6 A B-curve overcurrent trip with a 30 mA Type AC residual-current detection stage, all in a 1P+N (switched phase, solid neutral) package rated to break 10 kA per EN 60898 and IEC 60947-2. The B characteristic means the magnetic trip operates at 3 to 5 times In (18–30 A), making it the standard choice for resistive and general-purpose loads in domestic and light commercial final circuits — lighting, socket outlets, small appliances. The 30 mA residual-current element provides supplementary protection against direct contact and earth faults.
Breaking capacity and selectivity
Rated at 10 kA according to both EN 60898 and IEC 60947-2, this RCBO interrupts fault currents up to that level without external current-limiting fuses. The 10 kA rating covers most distribution-board applications where the prospective short-circuit current at the outgoing terminals is within that limit. Energy limitation class 3 means it lets through less let-through energy (I²t) than class 1 or 2 devices, improving downstream coordination and reducing arc-flash risk at the point of fault.
Integration into the panel
Occupies one 18 mm modular-width unit on the DIN rail. Depth is 77 mm (70 mm installation depth), height 125 mm. Mounting position is unrestricted — install in any orientation. The supply cable enters from below; a 600 mm pigtail on the neutral side simplifies wiring in pre-configured distribution boards. IP20 rating applies once the distribution board is installed and conductors are connected. Rated for ambient temperatures from -40 °C to +75 °C, with a maximum 95% humidity influence. Overvoltage category III and pollution degree 2 suit fixed-installation environments typical of DIN-rail distribution boards in industrial and commercial buildings.