The ABB OTM250E4C3D380C is a 4‑pole motorized automatic transfer switch (ATS) / change‑over switch designed to automatically transfer electrical loads between two independent AC power sources (such as utility mains and a backup generator) in three‑phase low‑voltage power distribution systems. It is part of ABB’s OTM automatic transfer switch family, built to enable reliable and safe switching with motorized automatic operation and manual override via a handle. The device includes mechanical interlocks to ensure that the two power sources remain electrically isolated and cannot be connected simultaneously, minimizing risk during transfer operations. This switch is suitable for industrial, commercial, and critical power installations where continuity of power and safe source change‑over are needed.
