The Siemens 5SL3163-7MB is a 1-pole SENTRON miniature circuit breaker rated 63 A at 400 V AC with a C tripping characteristic and a 4.5 kA breaking capacity per EN 60898. This is an active-production part, so it's a straightforward BOM-line fill for residential and light-commercial distribution panels where you need a 63 A branch circuit protector on a single phase.
What the ratings mean for fit
The C-curve means the magnetic trip kicks in at 5 to 10 times rated current — 315 to 630 A for this 63 A unit — so it handles motor inrush and transformer energization without nuisance tripping, unlike a B-curve that would trip at 3 to 5×. That makes it the right choice for mixed loads with moderate starting currents in residential or light-commercial infrastructure panels. At 4.5 kA per EN 60898, this breaker can safely interrupt a fault current up to 4.5 kA at 400 V AC. That's adequate for most residential and small commercial service entrances where the prospective short-circuit current stays under that threshold — common in many European installations. If your panel's fault level exceeds that, you'd need the 5SY series (6 kA or 10 kA) or a current-limiting upstream device. The 18 mm width (1 width unit) means it snaps into any standard DIN-rail distribution board and occupies a single module position. With a depth of 76 mm and an installation depth of 70 mm, it fits enclosures with standard 80 mm or deeper backboxes — no panel rework needed for a swap-in replacement.
Panel fit and wiring
Terminals accept 0.75 to 25 mm² solid or stranded copper — covers everything from a 1.5 mm² lighting circuit tail up to a 16 mm² feeder for a 63 A submain. The screw terminals take a tightening torque of 2.5 to 3 N·m (per the 5SL family spec). IP20 with connected conductors means it's protected against finger contact once installed in an enclosed panel; not rated for wet or outdoor exposure without an outer enclosure. Mounting position is any orientation, so it works in horizontal busbar arrangements or vertical DIN-rail layouts without derating. The sealable design allows a lead seal or lockout tag to prevent unauthorized operation — useful for utility-meter isolation or rental-property main switches.