ABB ST203M-C63 Industrial Safety Relay Module

ABB S203M-C63 (sometimes listed as ST203M-C63 on ABB catalogs) is a 3-pole miniature circuit breaker from ABB’s S200M family designed to protect three-phase circuits from overcurrent. It is rated at 63 A with a C-curve trip characteristic for moderate inrush, and it is specified for 230/400 V AC operation. The device provides a rated short-circuit current (Icn) of 10 kA and a rated ultimate breaking capacity (Icu) of 25 kA at these voltages, with a nominal insulation voltage Ui of 440 V. The footprint spans 3 terminal units (3 TE) and a mounting depth of about 69 mm. This model is commonly used in industrial power distribution, including panel boards, motor control applications, and general protective circuits where three-phase protection is required.