Title: Experimental study of opening arcs in air of AgNi contacts

Authors: Takwa El Bekri; Leila Chaâbane; Erwann Carvou

Addresses: Electrical Department, National School of Engineers Tunis, University of Tunis ElManar, LR-ACS-ENIT, BP 37 Le Belvédère 1002, Tunis, Tunisia ' Electrical Department, National School of Engineers Tunis, University of Tunis ElManar, LR-ACS-ENIT, BP 37 Le Belvédère 1002, Tunis, Tunisia ' Institute of Physics, University of Rennes 1, Rennes IPR, UMR no. 6541, du C.N.R.S. 35042 Rennes Cedex, France

Abstract: In the area of DC, power supply is made for resistive circuits which can contain elements with an inductive behaviour. This latest has an important effect on the transition phase that is favourable to the appearance of an electrical arc. The objective of this work is to have deeper knowledge on the arc's characteristics in the air. These characteristics are arc duration, arc energy, mass loss and surface degradation. Arc duration and mass loss increase with decrease of opening speed and increase of current. Mass loss for an inductive load is almost ten times greater than for a resistive one. The microscopic analyses show a more intense degradation with decreasing opening speed, due to a higher arc density. The inductance's effect was clearly observed on arc energy, on mass transfer and on arc duration. It is necessary to consider these effects in the contacts' design in DC to insure safety and reliability.

Keywords: AgNi contacts; silver nickel; air dielectric; arc duration; arc energy; erosion; opening arcs; mass transfer; surface degradation; inductance; contact design; DC power supply; resistive circuits; direct current.

DOI: 10.1504/IJMATEI.2014.066855

International Journal of Materials Engineering Innovation, 2014 Vol.5 No.4, pp.316 - 326

Received: 03 Oct 2013
Accepted: 08 Jan 2014
Published online: 26 Feb 2015 *

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