Step response of distribution arresters at lower currents

The current responses of seven distribution arresters are shown for increasing currents from below 100 A to over 1000 A. The 30% to 90% rise time of the voltage is approximately 30 to 40 ns. The seven arresters include three voltage ratings (10, 15 and 21 kV), three manufacturers, six metal oxide varistor types and one gapped SiC arrester. A delay in full current flow is shown to exist for most arresters for currents below 1000 A. In some cases, the arrester may delay for several hundred nanoseconds before beginning any conduction. More often, the current rises slowly, and after several hundred nanoseconds goes suddenly into a full conduction state