Experimental study on the influence of vent aperture size and distribution on arc motion and interruption in low-voltage switching devices

Enhanced switching performance during the interruption process is achieved when the arc quickly enters and stays within the splitter plate region with the arc itself remaining attached to the surface of the plates. It is well known that the vent design in low-voltage switching devices (LVSDs) has a significant influence on arc motion during an interruption event: however, there has been limited experimental studies correlating arc motion in the whole quenching chamber, including splitter plates region, to the size and distribution of the vent apertures, which are important for plasma flow in LVSDs. This paper uses high speed optical arc imaging to investigate arc motion in a LVSD as the vent aperture conditions are varied. It is shown that the arc moves further and more quickly if there is the larger vent size in the quenching chamber. In addition, the well distributed vent contributes to an increase in arc motion velocity and reduction in total arc duration.