ABB 1SDA050451R1 Current-Limiting Circuit Breaker

ABB 1SDA050451R1 is an Isomax S3X current-limiting circuit breaker for three‑phase power distribution. This fixed-mount, three-pole MCCB uses front terminals with protective releases and a thermomagnetic trip to interrupt fault currents quickly in AC systems. As part of ABB’s SACE Isomax S series, it is rated for operation up to 1000 V and a nominal current of 125 A, making it suitable for panelboards and switchboards in industrial installations where reliable interruption of short circuits and controlled fault current levels are needed. The 1SDA050451R1 designation identifies this specific 125 A, 3‑phase variant within the S3X family, ensuring compatibility with ABB's mounting schemes and S3X accessory ecosystem. With its current-limiting design, the device helps protect downstream equipment and enables selective protection strategies across distributed electrical networks.