ABB S203P-Z4 3-Pole Molded Case Circuit Breaker, Active

The 'Z' characteristic indicates a curve tailored for semiconductor protection or sensitive loads where very short overcurrent trip times are needed — common in control transformers, rectifier inputs, or electronic power supplies that cannot tolerate even brief overcurrents. The '4' suffix on this code typically denotes a specific breaking capacity or internal accessory configuration; verify the exact rating against the full ABB datasheet for your fault-current study.