Influence of Humidity on Endurance of Electrical Contact during Fretting Wear

Stable and low contact resistance is the basic requirement of each connector in electrical contact. There are many factors that affect contact resistance and investigated by many previous studies. In this work, the effect of wear debris to electrical contact endurance at different relative humidity is studied by fretting test. The contact resistance evolution curve at different relative humidity indicates that the wear debris is more effective to electrical contact resistance. The composition of the wear debris is analyzed by x-ray photoelectric spectroscopy. It is clearly revealed that wear debris give a sharp rise to contact resistance. In addition, measured results illuminated that the contact resistance is greatly reduced with the wear debris washed. Higher relative humidity can restrain the generation of debris to a certain extent. Physical model of debris formation is established to evaluate ultimate lifetime of contactor.