Siemens SENTRON 5SL3140-7MB — 1-pole C-curve 40 A MCB
The Siemens SENTRON 5SL3140-7MB is a 1-pole miniature circuit breaker with C-curve tripping characteristic, rated 40 A at 230/400 V AC. It breaks fault currents up to 4.5 kA per EN 60898, which covers most residential and light commercial branch circuits. The C-curve means it trips between 5 and 10 times rated current — standard for motor-starting and moderate inrush loads like small pumps or compressors in building infrastructure.
DIN-rail fit and panel integration
The 5SL3140-7MB occupies a single modular width unit (18 mm) on standard DIN rail, with a depth of 76 mm and height of 90 mm. That 18 mm width means it fits one-to-one in a panel originally laid out for any other 1-MW MCB — no re-spacing needed. The IP20 rating (with connected conductors) is typical for enclosed distribution boards; the sealable design lets a panel builder lock the toggle position after commissioning.