The Siemens SENTRON 5SL4440-7CC is a 4-pole miniature circuit breaker rated 40 A with a C tripping characteristic, designed for 400 V AC systems and a 10 kA breaking capacity per EN 60898. It occupies 4 modular width units (72 mm) on a DIN rail, making it a direct fit for residential and infrastructure distribution boards where a 4-pole C-curve MCB at this rating is specified.
What the ratings mean for fit
The C-curve trips between 5 and 10 times rated current (200–400 A magnetic release), which suits moderate inrush loads like lighting banks, small transformers, and motor starters in residential or light commercial panels. The 10 kA breaking capacity at 400 V AC (per EN 60898) means it safely clears a fault up to that prospective short-circuit current without welding contacts or cascading failure upstream — adequate for most final subcircuits in buildings where the fault level at the board is below 10 kA. The 4-pole design switches all three phases plus neutral simultaneously, which is required for three-phase final circuits where the neutral must be disconnected for isolation.
Panel integration notes
Mounts on a standard 35 mm DIN rail in any orientation (mounting position any). Depth is 76 mm, installation depth 70 mm; the 72 mm width (4 MW units) means it occupies four 18 mm slots in a distribution board. The IP20 rating with connected conductors applies — the terminals are finger-safe only when wired, so it belongs inside a closed enclosure. Supplementary devices (auxiliary switches, shunt trips, alarm contacts) can be clipped onto the right side without increasing width, per the product extension capability. The terminals accept the usual copper conductors for a 40 A circuit; sealable covers are available for tamper-proofing.