The Siemens SENTRON 5SU1654-1KK06 is a 2-pole RCBO combining overcurrent protection (C-curve, 6 A rated) with a 300 mA residual-current device in a single 36 mm-wide module. It's a current-production part — no lifecycle concerns for a new BOM line.
What the ratings mean for fit
The C-curve trips between 5× and 10× In (30–60 A magnetic), which handles motor inrush and lighting loads without nuisance trips. The 300 mA residual sensitivity is for equipment protection or circuits where 30 mA would cause false trips from leakage — think water heaters, pumps, or distribution subfeeds. The 10 kA breaking capacity per EN 60898 means it can safely interrupt a fault up to that level on a 50 Hz supply. Thermal derating is published: at 40 °C ambient the continuous rating drops to 5.7 A, at 50 °C to 5.4 A, and at 70 °C to 4.62 A. If the panel runs hot, size the breaker for the actual ambient, not the 30 °C nameplate.
Panel integration and mounting
Two modular-width units (36 mm) snap onto standard DIN rail. Depth is 77 mm (70 mm installation depth), so it fits flush in most distribution boards without a deep enclosure. Supply can enter from top or bottom. Touch protection is built in — no exposed live parts when wired correctly. Rated IP20 with the distribution board installed and conductors connected — that's normal for a panel-mount device; it's not a standalone outdoor unit.
Compliance and documentation
Halogen-free and silicon-free construction, pollution degree 2, overvoltage category III. The design is instantaneous (no intentional time delay on the RCD element). Energy limitation class 3 means it limits let-through energy well in a fault — good for downstream component protection.