A Comparison of Contact Erosion for Opening Velocity Variations for 13 Volt Circuits

Contact erosion and material transfer of several types of silver metal oxides have been studied by using a new model relay under different opening velocities and gaps. The test was conducted with 13 volt automotive inductive loads with break only operation. The opening speed of testing was adjusted to represent the different commercial relays. Contact material transfer was measured with digital balance. The results indicate that the material transfer is not only determined by metal oxide content but is also affected by opening speed and gap. Also the materials made by the internal oxidation method demonstrated stronger anti-erosion than materials made by the powder metallurgical method. The opening speed has a great influence on material transfer and opening gap affects the net material loss. A balance for transfer of contact material can be reached by adjusting the velocity of opening to a contact material.