Arc Runner / Horns

Arc runners, also known as horns, are metallic components strategically positioned within arc chutes of electrical switching devices. Their primary function is to capture, guide, and elongate electrical arcs that form during contact separation, directing them into arc-splitting plates or grids where they are cooled, deionized, and extinguished. This prevents arc re-strikes, minimizes contact erosion, and ensures safe interruption of fault currents in medium to high-voltage applications.

When contacts separate under load, an electric arc forms due to ionization. Arc runners, being conductive and positioned close to the contacts, attract the arc due to electromagnetic forces and thermal ionization. They guide the arc away from the contacts into the arc chute's splitting plates, where it is divided into smaller arcs, cooled by surrounding materials, and extinguished as current approaches zero.