The ABB S203-Z1 is a 3-pole molded case circuit breaker (MCCB) from the System pro M compact series, rated 1 A with a Z-characteristic trip curve for 480Y/277 V applications. The Z-curve provides a narrow magnetic trip band, typically 2-3x In, making it suitable for protecting sensitive electronic loads or long cable runs where standard B/C curves might nuisance trip on inrush.
Panel Integration
As a System pro M compact MCCB, the S203-Z1 mounts on DIN rail in standard distribution or control panels. The 1 A Z-curve rating means it occupies the same physical footprint as higher-current siblings in the series, so panel layout and busbar planning remain consistent across the S200 family.