The ABB RC5‑2/440 is a surge suppressor accessory designed to protect contactor coils and related control circuits from high‑energy overvoltage spikes. When an AC electromagnetic contactor coil is de‑energized, the stored magnetic energy can generate transient overvoltages that may interfere with electronics, damage insulation, or harm sensitive components. The RC5‑2/440 unit helps reduce peak overvoltage and suppress high‑frequency transient energy by damping these surge pulses. It attaches directly to the contactor or contactor relay and improves reliability and longevity of control circuitry in industrial motor control and automation systems.
