The Siemens SENTRON 5SL6140-7MB is a 1-pole miniature circuit breaker with a C tripping characteristic, rated 40 A at 30 °C and breaking 6 kA per EN 60898. That 6 kA rating is the standard fault-interruption capacity for residential and light commercial distribution boards — it safely clears a short-circuit up to that level without welding contacts or cascading damage upstream. The C-curve means the magnetic trip activates at 5 to 10 times rated current, so it tolerates the inrush of motor starters, small transformers, and fluorescent lighting banks without nuisance tripping on startup.
Rated for single-phase operation at 250 V AC and multi-phase at 440 V AC, with a maximum operating voltage of 440 V AC. The 40 A rating is continuous at 30 °C ambient; the thermal-magnetic element derates naturally in a warmer panel — no external adjustment needed. IP20 with connected conductors means it is touch-safe when installed in a live distribution board but not rated for washdown or outdoor exposure. Mounting position is unrestricted, and the 18 mm width (1 modular unit) snaps onto standard DIN rail, occupying a single slot in a consumer unit or sub-distribution board.
Panel Fit and Compliance
Depth of 76 mm, width 18 mm, height 90 mm — installs in any standard DIN-rail enclosure with 70 mm installation depth clearance. The housing is halogen-free and silicon-free, so it does not outgas corrosive compounds in sealed panels or near sensitive contacts. Sealable with a lockable cover to prevent unauthorized switching. Rated for overvoltage category III and pollution degree 2, covering fixed installations downstream of the main distribution board. Mechanical service life is 10 000 switching cycles typical.