Siemens SENTRON 5SU1354-6LB20 RCBO — 20 A, Type B, 1P+N
The Siemens 5SU1354-6LB20 is a SENTRON-series residual current circuit breaker with overcurrent protection (RCBO) rated at 20 A with a Type B tripping characteristic. It occupies 2 modular width units (36 mm) on a DIN rail and protects a single pole (1P+N) circuit. The breaking capacity is 10 kA per EN 60898 and 20 kA per IEC 60947-2, giving you selectivity headroom for downstream faults in a final distribution board.
What the ratings mean for your panel
The 20 A rating is at 30 °C ambient; derate to 18.8 A at 40 °C, 17.4 A at 50 °C, and 14.6 A at 70 °C — important when packing multiple RCBOs into a warm enclosure. The Type B characteristic trips instantaneously at 3–5× rated current, suited for resistive and general-purpose loads where no high inrush is expected. The short-time delayed G design (super resistant K) means the residual-current element tolerates brief leakage pulses from equipment like VFDs or UPS filters, reducing nuisance trips on sensitive circuits. Rated insulation voltage (Ui) is 264 V, surge voltage resistance is 4 kV, and overvoltage category III applies — this RCBO is designed for fixed-installation distribution boards, not portable equipment. The IP20 rating applies only when installed in a distribution board with connected conductors; the device itself is not sealed against dust or moisture ingress.
Installation and integration
Mounts in any position on DIN rail; supply top or bottom. Installation depth 70 mm, overall depth 77 mm. Width 36 mm (2 MW). Halogen-free and silicon-free.