What this MCB carries and where it fits
The ABB S801S-K40 is a 1-pole miniature circuit breaker from the S800S series, rated 40 A with a Trip Curve K characteristic on 230 V AC. The 50 kA interrupting capacity at 230 V AC handles high-fault panels. DIN rail mount, single module width. Snaps into any standard 35 mm DIN rail enclosure. The 1-pole form factor means it protects one phase — use three for three-phase motor circuits or combine with a 3-pole base for grouped protection.