What this MCB is and what the ratings mean for fit
The Siemens 5SL3132-7MB is a SENTRON miniature circuit breaker — 1-pole, C-curve, rated 32 A at 400 V AC, with a 4.5 kA breaking capacity per EN 60898. The C-curve (tripping between 5 and 10 times rated current) is the standard choice for general-purpose loads: lighting, socket circuits, small transformers, and moderate motor inrush. The 4.5 kA rating means it safely interrupts a fault current up to 4.5 kA at 400 V — adequate for most residential and light commercial distribution boards where the prospective short-circuit current stays under that threshold. At 32 A, this MCB handles a 7.4 kW resistive load on a 230 V single-phase circuit or roughly 22 kW on a 400 V three-phase supply. The 1-pole design (single modular width, 18 mm) snaps onto a standard DIN rail and occupies one 18 mm slot in the enclosure. Depth is 76 mm, which fits most flush-mount consumer units and small distribution boards. Rated for ambient temperatures from -40 °C to 75 °C, so it works in unheated utility rooms or outdoor enclosures in cold climates.
Panel fit and integration
Mounts in any position on a 35 mm DIN rail. The 18 mm width (1 MW) means it takes up one standard module slot. Depth of 76 mm (installation depth 70 mm) clears most enclosure doors and gland plates. IP20 with connected conductors — suitable for dry indoor panels; not rated for washdown or outdoor exposure without additional enclosure protection.