The Siemens 5SL7140-8RC is a 1-pole miniature circuit breaker (MCB) with a D tripping curve, rated 40 A and a breaking capacity of 10 kA at 240/415 V.
Snap-on DIN rail mount, standard 1-pole width (18 mm per pole). Integrates into any Siemens SENTRON or third-party distribution board. The D curve and 40 A rating make it a common choice for motor feeder circuits in panel builds — verify the upstream selectivity with the main breaker during coordination study.