What the ratings mean for fit
The 5SL1140-6MB is a SENTRON 1-pole miniature circuit breaker rated 40 A at 230/400 V AC with a B tripping characteristic. The B curve means it trips at 3–5 times rated current — suited for resistive and lighting loads where inrush is low, not for motor starting circuits that need a C or D curve. The 3 kA breaking capacity per IEC 60947-2 is the maximum fault current it can safely interrupt; install downstream of a higher-rated upstream device if the prospective short-circuit current exceeds 3 kA. The 1 MW width (18 mm) lets it snap onto a standard DIN rail, occupying one position in a residential or light-commercial distribution board.
Where it fits in the panel
Mounts in any orientation on a DIN rail, with 70 mm installation depth behind the panel surface. Rated IP20 with connected conductors — suitable for enclosed distribution boards, not for wet or dusty environments. The sealable feature allows the installer to lock the toggle position after commissioning, preventing unauthorized reset or isolation. Halogen-free and silicon-free construction matters in public-building or clean-room installations where off-gassing must be controlled.