Mechanism of Contact Erosion and Estimation of Cumulative Contact Erosion under Multiple Switching in Low‐Voltage Switches

This paper describes both the mechanism of contact erosion under multiple switching and a method that estimates the contact erosion transition in low‐voltage switches. The contact height is decreased due to the contact erosion in multiple switching, and this reduces the overtravel. The contact force is decreased by 31% and the opening velocity is decreased by 55% due to a 1 mm reduction of overtravel in the testing switch. This situation increases the bounce time in the making (closing) operation and leads to an increase arc current ( I arc ) and arc duration (Δ t ) at make. On the other hand, the situation has almost no effect on the interruption characteristics. We clarified that I arc n Δ t at the make is increased, and the contact erosion is accelerated. Based on this mechanism, we constructed a model that calculates I arc n Δ t every switching. Finally, we proved that the transition of the contact erosion in multiple switching can be estimated using the model. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.