Investigation of the Effect of Different Current Loads on the Arc-Erosion Performance of Electrical Contacts

S. Biyika and M. Aydinb aKaradeniz Technical University, Department of Metallurgical and Materials Engineering, 61080 Trabzon, Turkey bKaradeniz Technical University, Department of Mechanical Engineering, 61080 Trabzon, Turkey

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In this study, arc-erosion experiments using contactors were performed under inductive loads for up to 40000 switching operations to investigate the effect of different current loads on the arc-erosion performance of electrical contacts. Determination of the mass loss was performed after every 5000 operations. The arc-eroded surfaces were examined using scanning electron microscopy. The chemical composition near the arc was determined by energy dispersive X-ray spectroscopy. The results show that the contact surfaces are greatly affected by arc-erosion, resulting in mass loss due to material migration and/or evaporation. In addition, the arc-affected zones become bigger with the increase in the number of switching operations, especially at 20 A. However, electrical cleaning improves the contact performance by reducing the contact resistance due to breakdown of the non-conducting oxide films formed between 20000 and 25000 switching operations at 20 A. The stationary contacts experience major erosion, whereas the movable contacts suffered less contact erosion under each current load.

DOI: 10.12693/APhysPolA.129.656 PACS numbers: 81.70.-q, 07.50.-e, 84.32.Dd