ABB OXA400U3X2QB Industrial Control Relay Module

ABB OXA400U3X2QB is a 3-pole, 400 A automatic transfer switch control unit in ABB’s TruONE ATS family. The 400 A variant (OXA400U3X2QB) provides Level 2 control for automatic source selection and sequencing between two power sources, enabling a fast, orderly transfer when the primary supply changes and helping maintain continuous power to critical loads in industrial environments. Part of the TruONE ATS platform, this module coordinates switching within ABB’s transfer-switch configurations and control interfaces for high-availability power distribution. The OXA400U3X2QB designation identifies a specific high-current, multi-pole implementation in the OXA400…OXA600U3X2QB series, making it suitable for integration with ABB automatic transfer switch assemblies that require robust control logic and reliable interconnections. Engineers select this model when a 400 A service current and 3-pole topology are prerequisites for meeting uptime requirements, ensuring minimal transfer time and predictable operation under source failure conditions. This description reflects the model’s role as a dedicated control component within ABB’s TruONE ATS ecosystem, designed to support industrial applications where dependable automatic source transfer is essential.