What the S801S-D100 is and what the D-curve means for your panel
The ABB S801S-D100 is a 1-pole D-curve 100A molded case circuit breaker from the S800S series. The D-curve trip characteristic means it is designed for loads with high inrush currents — think motor starting, transformer energization, or welding equipment — where the magnetic trip threshold sits at 10 to 20 times rated current, so it holds through the startup surge without nuisance tripping.