Flame Suppression Technique in Arc Tracking of Circuit Boards

The problem of arc tracking in power electronic enclosures was studied through simple bench-top experiments aimed at understanding the phenomenon. Experiments were performed to isolate the causes of arc tracking on PCB boards with high-powered electrodes subjected to a Solventol/water mixture contamination. These experiments show that a minimum electrode spacing of 1 mm would be susceptible to arc tracking. A larger spacing of 3.2 mm appears to prevent arc tracking. In the event that arc tracking causes combustion, a passive flame suppression method is indicated. This method comprises of four layers of off-the-shelf expanded metal network. Tests show that the flame is quenched in about one minute, with minimum damage to the plastic enclosure.