ABB ST203M-C20 Safety Relay Module DIN Rail Mounted

ABB ST203M-C20 (also listed as S203M-C20) is a 3-pole miniature circuit breaker designed for DIN-rail mounting in ABB’s System Pro M Compact S200M family. It is rated for 20 A with a Type C (IEC) tripping curve and provides a declared short-circuit breaking capacity up to 10 kA at 277/480 VAC, with a rated voltage up to 440 VAC. The device is UL 1077 listed as a supplementary protector and RoHS compliant, making it suitable for commercial and industrial panel protection. Cross-listed ABB catalogs identify this model as 2CDS273001R0204 (S203M-C20), reflecting its place in the compact MCB lineup and its DIN-rail mounting footprint for space-efficient distribution or control panels.