What this RCBO is and what it does
The Siemens 5SU1354-6LB16 is a 2-pole (1P+N) RCBO from the SENTRON family — a combined residual current device and miniature circuit breaker in one 36 mm-wide module. It carries a 16 A rated current at AC with a B tripping curve, meaning it trips between 3 and 5 times rated current for fast disconnection on short circuits while tolerating modest inrush from resistive loads. The Type A residual current detection catches pulsating DC fault currents up to the rated sensitivity, which is what you get from single-phase rectifiers in switched-mode supplies or variable-speed drives. Breaking capacity is rated at 10 kA per EN 60898 and 20 kA per IEC 60947-2 — the higher figure applies when the device is used as a distribution board component, giving headroom in industrial panels with higher prospective fault current.
What the ratings mean for fit
The 16 A rating at 30 °C is the baseline; at 40 °C it derates to 15.2 A, and at 70 °C it drops to 12.32 A. If this RCBO sits in a crowded enclosure where ambient hits 50 °C, expect 14.4 A continuous — plan the load accordingly. The B curve means magnetic trip at 3–5× In (48–80 A), so it's a fit for lighting circuits, socket outlets, and general-purpose distribution rather than motor starts that draw 6–10× FLA. The design carries 'short-time delayed G, super resistant K' — the G characteristic introduces a deliberate delay to tolerate brief surge currents (like capacitor inrush or transformer magnetising), while the K variant is built for higher mechanical and thermal endurance in frequent-switching applications. This isn't a generic domestic RCBO; it's rated for industrial panel duty where nuisance tripping costs line time. Mounting position is unrestricted, and the supply cord can enter from top or bottom — useful when retrofitting into a panel where the busbar arrangement is already set. The 77 mm depth (70 mm installation depth) fits standard 18 mm-module distribution boards with room for wiring.
Panel integration notes
Width is 36 mm (2 modular width units), so it occupies two 18 mm slots on a standard DIN rail. The IP20 rating applies when installed in a distribution board with conductors connected — the enclosure provides the physical protection; the RCBO itself is finger-safe only when mounted. Halogen-free and silicon-free construction matters for environments where outgassing during a fault could contaminate sensitive contacts or optics — clean rooms, data centres, or food-processing panels where silicone-based lubricants are absent.