What this RCBO is and what it does
The Siemens 5SU1654-1KK10 is a SENTRON-series residual-current circuit breaker with overcurrent protection (RCBO) — one device that combines an MCB and an RCCD in a single 2-module-wide package. It's rated 10 A at 30 °C with a C-curve tripping characteristic, so it handles moderate inrush from small motors or lighting banks without nuisance trips, and clears faults at up to 10 kA per EN 60898. The residual-current element is type AC, tripping at 300 mA — sized for general socket-outlet or sub-distribution protection where a lower 30 mA threshold isn't required.
Fit and panel integration
This RCBO snaps onto standard 35 mm DIN rail, occupying 2 modular width units (36 mm). Depth is 77 mm, installation depth 70 mm — it fits flush in most residential or light-commercial distribution boards without protruding past the gland plate. The supply can enter from top or bottom, and the device can be mounted in any position. Rated IP20 with the distribution board installed and conductors connected, so it's strictly indoor panel use — no washdown or outdoor exposure.
Temperature derating — what the numbers mean
The 10 A rating holds at 30 °C ambient. Above that, the continuous current must be reduced: 9.5 A at 40 °C, down to 8 A at 70 °C. If the panel runs hot — say, a crowded enclosure near a boiler or in a rooftop cabinet — size the upstream protection accordingly. The device itself is rated for ambient from -40 °C to 75 °C, so storage and occasional high-temp operation are fine as long as the load is derated.