research on current diffusing mechanism of lightning struck buildings’plastic-steel windows and doors

摘要

Using lightning surges generated by impulse voltage generator which conform to the International Standard IEC(wave crest 1.2 μ s,wavelength 50 μ s), we made an impulse experiment of lightning strikes on buildings’ plastic-steel windows and doors, and analyzed the diffusing mechanism. The result indicates that the principle is electric current flashover takes place at the PVC material surface of plastic-steel windows and doors. The diffusing current access is that lightning electric current arrives at the metallic screw at the PVC material surface of plastic-steel windows and doors by surface flashover mechanism which takes place at the PVC material surface of plastic-steel windows and doors first, then arrives at the metallic hardware in plastic-steel windows and doors by the metallic screw, spreads rapidly in ground by buildings’ lightning protection equipments that connect with each other in plastic-steel windows and doors finally. Only making the equipotential connection of metallic hardware in buildings’ plastic-steel windows and doors and making the equipotential connection with buildings’ lightning protection equipments can we insure the minimum damage of lightning and static electricity on devices 。