Spark Gap Breakdown at EMP Threat Level Rates of Voltage Rise

Electrical Surge Arrestors (ESAs) are used extensively for lightning and EMP protection on conductors which may be excited by these hostile environments. In-situ measurements of peak pulse voltage were performed at rates of voltage rise from 200 to 2000 kV/¿s on several types of surge arrestors and combinations of spark gaps and filters. These data are presented along with samples of previous measurements. The effects of lead inductance and low impedance loading by the filter input capacitance are illustrated. Experimental results are compared to theoretical predictions of an ESA model used for EMP analyses.