RF current produced from DC electrical arcing

The RF current produced by arcing in air at 380Vdc was investigated for current sranging from 2A_dc to 120A_dc. Time resolved frequency maps were obtained using a real-time spectrum analyzer (RSA) to show how polarity, electrode material and current magnitude affected the measured RF current intensity. These dc signatures were also compared to previously obtained ac signatures using the same materials and methods to show differences between ac and dcarcing. This work is useful to those who want to gain an understanding of RF currents generated in arcs, especially for those developing arc fault sensing devices. Examples of dc systems represent systems built to meet North American standards, but the underlying physics and results can apply to any country.