ABB ST203M-B16 Industrial Control Relay Module

ABB ST203M-B16 is a 3-pole miniature circuit breaker (MCB) in the ST200M family, rated for 16 A to protect control and automation circuits in industrial panels. It features a B-curve trip characteristic and UL 1077 recognition, with a 10 kA interrupting rating for rapid fault clearance on 240 V AC and 125 V DC circuits. The official catalog designation is 2CDS273334R0165, and the model is also listed as ST203M-B16 or S203M-B16 in ABB catalogs. This 3P device is designed for protection of three-phase control circuits in machine control, PLC panels, and other industrial installations where compact overcurrent protection is required. The combination of the 16 A rating, B-curve trip, and high interrupting capacity makes it suitable for safeguarding small to medium control loads in electrical cabinets and integrated control systems.