Arc Splitters / Deion Plates

Arc splitters/deion plates are critical components within an arc chute or arc extinguishing chamber of electrical switching devices (e.g., circuit breakers, contactors). Their primary function is to rapidly extinguish the electric arc that forms when contacts separate under load. They achieve this by physically splitting the arc into multiple, shorter, and cooler series arcs, which increases the total arc voltage beyond the system voltage, forcing current zero. Simultaneously, the plates act as heat sinks, cooling the arc plasma, and provide surfaces that promote recombination of ions and electrons, effectively deionizing the arc path to prevent re-strike.

When an arc is drawn between separating contacts, it is driven into a stack of closely spaced, metallic plates (the arc splitters). The arc root attaches to a plate, then splits and re-forms across the gaps to the next plate, creating a series of shorter arcs. Each split arc has its own anode and cathode voltage drop, summing to a total arc voltage that exceeds the system's recovery voltage. The metal plates absorb thermal energy, cool the arc plasma, and provide a conductive path for charged particles to recombine, extinguishing the arc.