Characterization of Glowing Contacts using Optical Emission Spectroscopy

Glowing contacts are an interesting and complex phenomenon. They may be associated with residential arc faults and fire hazards. Previous investigation has shown that formation needs certain environmental and current conditions. The aim of this paper is to provide further understanding of their formation mechanism. Optical emission spectroscopy was employed to investigate the state of gases along the glowing contact surface. A high-speed video camera was used to observe glowing contact behavior at frame rates up to 150 fps. Based on emission spectroscopy and high-speed video images, analysis was carried out into the mechanism for current conduction at the contact interface. These results were correlated to glowing contact behavior at different current levels and three modes were identified.