Allen-Bradley 520F-BOD Two-Speed Motor Starter

The Allen-Bradley 520F-BOD is a NEMA Size 1, open-type two-speed motor starter from Rockwell Automation’s 520 family, designed to provide two selectable speeds for a three‑phase motor in a compact, non-enclosed package. It uses a 120 V alternating-current coil for control and includes eutectic alloy overload protection for motor safety. With a continuous current rating of 27 A, it supports horsepower ratings that vary by supply voltage: about 7.5 HP at 200–230 VAC and 10 HP at 460–575 VAC. As a two-speed constant or variable torque starter, it is engineered to integrate with Bulletin 520 control systems, enabling smoother acceleration and energy‑efficient operation for small to mid‑sized motors. This device is suited for applications where switching between two motor speeds is beneficial, such as fans, pumps, or conveyors, and is designed to be wired in an open, non‑enclosed configuration that matches typical industrial control panels and legacy 520-series installations.