Siemens SENTRON 5SP9340-7KC47 is a 3-pole miniature circuit breaker rated 40A with C-curve tripping characteristic, designed for 400V AC at 50 Hz. Terminals accept solid and stranded conductors from 0.75 to 50 mm² (AWG 14 to 2), with tunnel terminals at both top and bottom. That cross-section range covers everything from control wiring to main feeder taps — no need for reducers or pigtails on a 40A circuit. Mounts on standard DIN rail (35mm) or screw fixing, any orientation, with a 92 mm installation depth. The 4.5 width units (about 81 mm) mean it occupies a bit more rail than a typical 3-pole MCB — check your enclosure's gutter space before committing the panel layout.
Approvals include IEC 60947-2 certification for the 50 kA rating. The part is halogen-free and silicon-free, which simplifies compliance documentation for RoHS and REACH declarations.
Integration Notes
Tightening torque for screw terminals: 2.5 to 3.5 N·m (22 to 31 lbf·in). Use a torque screwdriver — under-torquing risks thermal rise at 40A continuous; over-torquing can strip the tunnel clamp. Ambient operating range -25 to +45 °C, storage -40 to +75 °C. The 95% humidity tolerance at +55 °C (periodic) matters for non-climate-controlled panels in washdown areas or tropical installs. Shock resistance 150 m/s² at 11 ms half-sine per IEC 60068-2-27; vibration 50 m/s² at 25-150 Hz and 60 m/s² at 35 Hz (4 sec) per IEC 60068-2-6. Mechanical service life rated 20,000 switching cycles typical. For frequent switching applications (e.g., motor start-stop), that's adequate for years of service; for daily load-break duty, consider a contactor downstream to preserve the MCB's mechanical endurance.