It breaks fault currents up to 10 kA per EN 60898 and 20 kA per IEC 60947-2 at 400 V AC — the higher IEC figure gives you headroom for industrial panel coordination where the upstream transformer can deliver more fault current than a residential service. Tunnel terminals on both top and bottom accept conductors without needing ring lugs, which speeds up panel wiring. The 70 mm installation depth matches the standard SENTRON 5SP footprint, so it clips onto the same DIN rail as other 5SP units without protruding past the enclosure door.
What the B-curve and 40 A rating mean for your circuit
The B-curve trips magnetically between 3 and 5 times rated current (120–200 A for this 40 A unit). That makes it a good fit for resistive or lighting loads with low inrush — think heater banks, incandescent strips, or general-purpose socket circuits. For motor or transformer starts that draw 6–10× rated current momentarily, a C-curve sibling would be the better call to avoid nuisance tripping.
Panel fit and approvals
The 2-pole body occupies two modular width units (36 mm), leaving room alongside other 5SP breakers for a clean, ganged layout. The 10 kA rating under EN 60898 satisfies most building-distribution requirements; the 20 kA rating under IEC 60947-2 covers industrial panels where higher fault levels are expected.