Lichtbogenlösefähigkeit

Lichtbogenlöse, translating to "arc quenching" or "arc suppression" in English, refers to the process of extinguishing an electrical arc. Electrical arcs are sustained discharges of current through a normally non-conductive medium, typically air. They occur when the voltage across a gap becomes sufficiently high to ionize the medium, creating a conductive plasma channel. While arcs can be useful in applications like arc welding, they are generally undesirable in electrical switching devices.

The primary goal of arc quenching is to prevent damage to electrical equipment, such as contactors, circuit breakers, and switches, and to ensure the safety of operations. When contacts in an electrical circuit separate, an arc can form across the gap. This arc carries current and generates significant heat, which can melt or erode the contact surfaces, leading to premature failure of the device.

Various methods are employed for arc quenching. One common technique is to rapidly increase the distance between the separating contacts, stretching the arc and reducing its cross-sectional area, thus increasing its resistance. Another approach involves cooling the arc plasma to reduce its conductivity and extinguish it. This can be achieved through techniques like blowing a stream of air or gas across the arc, or by using arc chutes that have a series of metal plates to divide and cool the arc. Specialized materials and designs of electrical contacts also play a role in minimizing arc formation and facilitating its extinction. The effectiveness of arc quenching is critical for the reliable operation of many electrical systems.