The ABB OTM250E4C11D380C is a 4‑pole automatic transfer switch (ATS) / motorized change‑over switch designed to automatically and reliably transfer electrical loads between two independent AC power sources (e.g., utility mains and a backup generator) in three‑phase low‑voltage power distribution systems. It is part of ABB’s OTM_C_D family of motorized change‑over switches, which provide safe, coordinated transfer operations with motorized automatic control and manual override capability. The switch incorporates mechanical interlocking and isolation to prevent both sources from being connected at the same time, improving safety and continuity of service in industrial, commercial, and critical power applications. Motor operation enables integration with external ATS controllers for fully automatic operation
