The Siemens SENTRON 5SL4440-7RC is a 4-pole miniature circuit breaker rated 40 A with a C tripping characteristic. It interrupts fault currents up to 10 kA at 415 V AC per EN 60898 — the standard for overcurrent protection in residential and light commercial distribution boards. The C curve means it holds through moderate inrush (typical of small motors, transformers, or lighting banks) and trips fast on a hard short.
Fit and mounting
Snaps onto a standard DIN rail. At 18 mm wide (1 MW), it occupies a single modular slot — critical when you're packing four poles into a tight enclosure. Depth is 76 mm, installation depth 70 mm, so it clears a 90 mm deep enclosure with room for wiring. Mount in any position; pollution degree 2 (normal dry indoor environment) and overvoltage category III (distribution-level transients) cover the usual panel install.