Estimation of the burn-back rate in high breaking capacity fuses using fast imagery
Résumé
The viewing of the erosion rate of the fuse element in High Breaking Capacity fuses is carried out using the fast imagery. The rotating drum camera we used provides until 160 frames to observe the arc extinction throughout the phenomenon which lasts 4 ms. From this frames, we show that three stages follow each other with a different value of the burn-back rate: the maximum values are obtained at the beginning of the phenomenon and are equal to 6.65 m.s-1 and 5.81 m.s-1 respectively for silver and copper fuse elements. The direct observation of the burn-back mechanism shows a reproducible disequilibrium depending on the nature of the electrode: the cathode erosion rate is 1.7 times that for the anode rate in the case of silver, and 1.2 times that for the anode in the case of copper.