Investigations on the Effects of Different Strand Surface Conditions on the Inter Strand and Strand/Connector Resistance

The basic function of wire connection systems is to assure a low loss and stable long term electromechanical connection between the wire and connector. In order to meet the increasing demands of this function, it is necessary to provide a sufficient electromechanical inter strand and strand/connector contact. An important parameter for this is the strand surface condition. The strand surface condition is affected by surface oxides and contaminations which influence the formation of electromechanical contact areas. Therefore, detrimental storage conditions of the wire can increase the contact resistance and degrade the electrical connection quality. This study presents a measurement method which analyzes the resistance relations of the electromechanical inter strand and strand/barrel contacts. The measurement method is used to investigate the influences of the wire strand surface condition and the number of wire strands within a tubular crimp connection. The results show the impact of these parameters on the quality of the electromechanical connections. Finally, an analogous resistance model is used to determine the effect of the parameters to the current distribution and the resistance relationships within the crimp connection. Overall, this study provides a deeper understanding of the relevancy of the wire for the electromechanical connection and the design of crimp connections.