Erosion Characteristics of Silver-Based Contact Materials In a DC Contactor

Electrical life tests in a dc contactor are performed under DC4 and DC5 conditions. Results from our observations and erosion measurements are compared for different silver-based contact materials. For the device used a relation can be established between the arc energy and material loss and transfer. The erosion mechanism during the make operation determines the overall arc erosion to a larger than expected extent. Silver nickel 90/10 stands out as the contact material with the lowest erosion rate under both conditions.