ABB 2CSS255101R0405 SN201-B40 1P+N 40A B-Curve 6kA Miniature Circuit Breaker (MCB)

Topping out the SN201 1P+N range at In 40 A, the ABB SN201-B40 (SKU 2CSS255101R0405) still fits the same 1-module, 18 mm DIN-rail footprint as its lower-current siblings, with an identical type B curve and 6 kA breaking capacity at 230 V AC. Choose it for the highest-current single-phase final circuits this frame size supports, since a higher load would require stepping up to a different frame rather than a higher B-curve rating.

Technical Specifications

Certifications & Standards

• IEC/EN 60898-1

Selection Notes

At the top of the SN201 range, the 40 A SN201-B40 still fits the same 1-module, 18 mm housing as the rest of the family, with no change to the type B curve's 3-5× In instantaneous trip band or the 6 kA breaking capacity at 230 V AC. This is the rating to choose when a single-phase resistive or lightly inductive circuit's load approaches the frame's current ceiling; beyond 40 A, a larger-frame device rather than a higher B-curve rating is needed. As with the rest of the range, avoid it on circuits with significant motor or transformer inrush.