What the ratings mean for fit
The Siemens SENTRON 5SP5291-7 is a 2-pole miniature circuit breaker rated 100 A at 440 V AC with a C tripping characteristic. The C-curve means it trips at 5 to 10 times rated current — sized for motor-starting inrush or moderate transformer loads on a 50 Hz supply, not for purely resistive lighting circuits where a B-curve would be tighter. On the DC side it is rated 250 V, with a 10 kA breaking capacity per EN 60898-2 and 15 kA per IEC 60947-2, so it handles DC fault currents up to those levels without welding the contacts. At 3 width units (54 mm wide), it occupies three 18 mm DIN-rail slots. The 70 mm installation depth and 76 mm overall depth mean it clears most standard enclosures, but check the gland-plate clearance on shallow 80 mm deep panels. Tunnel terminals top and bottom accept solid or ferruled conductors — no lug adapters needed for the 100 A rating, though the terminal sizing should be verified against the conductor cross-section for the full load. Rated for any mounting position and any power-supply cord position, so it fits without orientation restrictions inside the panel. The sealable design allows the installer to lock the toggle position, which matters for tamper-proof circuits or compliance with local isolation rules.
Panel integration notes
Mounts on standard DIN rail (35 mm) or via screw fixing. The IP20 rating with connected conductors means it is intended for enclosed panel use, not washdown or outdoor exposure. Halogen-free and silicon-free construction reduces corrosion risk in sealed enclosures and meets material restrictions for clean-room or food-beverage adjacent areas. Overvoltage category 3 means it is rated for fixed-installation use downstream of the main distribution board — standard for branch-circuit protection in industrial control panels. Touch protection is built into the terminals, so no additional finger-safe shrouds are needed for the front face.
Environmental and mechanical endurance
Rated for -40 °C to 75 °C ambient, with up to 95% humidity. Shock resistance tested at 150 m/s² for 11 ms half-sine (IEC 60068-2-27) and vibration at 50 m/s² from 25 to 150 Hz (IEC 60068-2-6). These figures confirm it survives transport and panel-mount vibration on conveyor lines or pump skids without nuisance tripping.