Technical Feasibility of Diagnosis of Electrical Busbar Connections by Infrared Thermography

Infrared thermography is widely used in predictive maintenance of electrical connections, in which an increase of their temperatures is an indicative of failure. However, there are few published studies about the use of this technique in the analysis of failures of screw connections of electric busbars, a device widely used in switchgear. In this context, the purpose of this study is to analyze the technical feasibility of diagnosing connections of electric busbars using infrared thermography. An experimental planning was elaborated and executed by means of which three busbars of different dimensions, connected by screws of different diameters, were analyzed. The aim was to evaluate the relation between temperature rise and the conformity of the connections, represented by the torque applied to the screws. The results obtained show insignificant temperature differences under different quality conditions in the electrical connections. This led to the conclusion that there is no significant correlation between the measurable variable by infrared thermography - temperature rise - and the conformity of the electrical connection - torque in its screws making impossible to diagnose failure in electrical busbar connections using thermographic inspection.