Part identity and key ratings
The Siemens 5SL6140-6RC is a SENTRON miniature circuit breaker rated 40 A, 1-pole, with a B tripping characteristic and a breaking capacity of 7.5 kA per EN 60898. The 7.5 kA rating at 415 V AC tells you this breaker can safely interrupt fault currents up to that level without welding contacts or cascading upstream, which is the figure that governs coordination with the upstream protective device. The single-pole design occupies one modular width unit (18 mm) on a DIN rail, with a depth of 76 mm and an installation depth of 70 mm. It accepts supply voltage up to 250 V AC single-phase or 440 V AC multi-phase, and is rated for 50/60 Hz networks.
The 18 mm width (1 MWU) fits standard panel layouts. Sealable design allows tamper-proofing after commissioning. Terminal design accepts copper conductors typical for 40 A branch circuits; strip length and torque values follow the manufacturer's installation instructions.