The ABB S803S-D20 is a 3-pole miniature circuit breaker from the S800S series, rated 20 A with Trip Curve D, designed for 230 V AC circuits and a 50 kA interrupting rating.
Trip Curve D and deployment context
The 20 A rating handles steady-state loads up to that current, while the D curve allows a brief multiple of that for inrush, then trips fast on hard faults. In a panel, the DIN-rail footprint means it clips onto the same profile as other S800S breakers, so a multi-pole distribution block stays aligned without adapters.
Comparison with S803S-D63
The closest sibling in the same S800S family is the S803S-D63, which shares the same 3-pole DIN-rail form factor, 230 V AC rating, and 50 kA interrupting capacity, but is rated 63 A instead of 20 A. Both use Trip Curve D, so the selection between them is purely about the load current — the D20 for circuits up to 20 A, the D63 for circuits up to 63 A. They drop into the same panel layout without rewiring; the physical footprint is identical.