Siemens SENTRON 5SQ2170-0KA08 — 1-pole C-curve MCB at 8 A
The Siemens SENTRON 5SQ2170-0KA08 is a 1-pole miniature circuit breaker with a C tripping characteristic, rated 8 A at 240 V AC, 50 Hz. Its 3 kA breaking capacity is certified per both EN 60898 and IEC 60947-2 — that means it's tested to safely interrupt fault currents up to 3 kA under the respective standard's conditions. The C-curve (5–10× In) is the standard choice for general-purpose branch circuits feeding inductive loads like contactor coils, small motors, or lighting ballasts where the inrush isn't extreme but exceeds a B-curve's threshold.
Panel fit and integration
Occupying a single modular width unit with an installation depth of 55 mm, this breaker snaps onto standard DIN rail.
What the ratings mean for your panel
The 3 kA breaking capacity is the key coordination number. In a panel where the prospective short-circuit current is under 3 kA, this MCB clears a fault without upstream devices needing to trip.