The Siemens 5SM3111-0KL is a 2-pole residual current circuit breaker (RCCB) from the SENTRON 5SM3 series, type AC, rated 16 A with a 10 mA trip threshold at 230 V AC. It snaps onto DIN rail (REG) and occupies 2 width units (about 36 mm), with N on the left side.
Ratings that matter for panel fit
Terminals accept 1 to 16 mm² solid or stranded copper, torqued to 2.5–3 N·m. The instantaneous design means no intentional delay — it trips within a cycle on a residual fault, which is what you want for shock protection but means nuisance tripping is possible on circuits with high inrush or capacitive leakage.
Wiring and mounting notes
Supply can enter from top or bottom — no orientation restriction. The IP20 rating applies only when the distribution board is installed with conductors connected, so the device itself is not touch-safe until enclosed. Silicon-free construction is confirmed, relevant for potting or conformal-coating environments where silicone outgassing can cause contact issues.