The Effect of Dust Contamination on Electric contacts

Dust seriously influences the reliability of electric contacts. Evidence shows that failure of electric equipment is closely relaterl to this problem. Scanning electron microscope (SEM) photos investigating the morphology and size distribution of the dust particles are shown. The composition of the particles was examined by X-ray energy spectroscopy (XES). Electric contact experiments show that the contact resistance was not only affected by the geometry of the surface but also strongly dependent on the normal force and electric current effect which causes nonlinear and irreversible contact resistance. Theoretical explanation for these phenomena is given by means of the plastic deformation which is due to the load or the joule heating that causes dust particle embedding into the surface. Increasing load or electric current is not an acceptable solution. Future work for dust research is also briefly discussed.