Evaluation of contact service life of electrical connections

An approach to evaluating the parameters determining the contact service life of electrical connections is suggested. Changes in the contact properties resulting from operation under normal service conditions are related to the growth of an oxide layer on the contact surface. A simplified contact configuration comprised of n evenly distributed single spot cylinders was used to develop a model describing the degradation of contact resistance. The proposed model and the expression for the changes in contact resistance with time provide a useful and accurate method for estimating the service life of a connector. The error of estimation is within 10-15%. An algorithm which enables estimation of the remaining useful service life of a connection is derived. This method allows maintenance strategies and diagnostic procedures to be established for electrical equipment in the field operating under slowly changing conditions