What this MCB is and where it lands
The Siemens 5SL6140-7BB is a SENTRON miniature circuit breaker — a single-pole unit with a C tripping curve, rated 40 A, and a breaking capacity of 6 kA per both EN 60898 and IEC 60947-2. It's built for residential and infrastructure branch circuits: lighting, socket outlets, general-purpose loads where the inrush isn't extreme but you still want the C-curve's moderate magnetic trip threshold.
What the ratings mean for fit
The 6 kA breaking capacity is the same under both EN 60898 (household standard) and IEC 60947-2 (industrial standard) — so this breaker can interrupt a fault up to 6 kA without welding its contacts or cascading damage upstream. That's enough for most residential and light commercial panels where the prospective short-circuit current stays under that level. The C-curve trips magnetically between 5 and 10 times rated current (200–400 A for this 40 A unit), which suits motor-starting and fluorescent-lighting inrush better than a B-curve would.
Panel fit and integration
The 5SL6140-7BB snaps onto standard DIN rail, occupies one modular width unit (18 mm), and mounts in any position. Depth is 76 mm with 70 mm installation depth behind the panel. IP20 with conductors connected — suitable for enclosed distribution boards, not for wet or washdown locations. Sealable design allows locking the toggle to prevent unauthorized operation.