- Author
- Robertsson, A. | Karlsson, S. E. | Strand, G. | Nilsson, G.
- Title
- Smaltskador pa Elektriska Ledare. [Melt Damages on Electric Wires.] (Abstract in English)
- Coporate
- Universitetet i Linkoping, Sweden Linkoping University, Sweden
- Report
- Report 20, August 5, 1988, 36 p.
- Keywords
- electric wire | melting | damage
- Abstract
- Different types of electrical melt damages have been initiated on insulated and uninsulated copper conductors in both normal atmosphere and fire atmosphere. Damaged areas and melt beads arisen from electrical short-circuits as well as from heating have been studied, mainly concerning oxygen content, using metal microscopes, a scanning electron microscope and an Augerelectron spectrometer. No safe common method to separate primary damages, which have initiated a fire, from secondary damages, which have occurred due to a fire, has been developed. For a certain type of damages, however, a metallogrpahic method indicates possibilities to separate some primary damages from the secondary ones. One method to separate melt beads from primary damages from those from secondary damages using Auger electron spectroscopy has been patented in USA. Our studies, however, show that not even this method is completely reliable. The oxygen content in the surface layer of a melt bead does not only depend on the type of damage but also on the thermal pre- and post-history of the electrical damage.