Abstract: A high voltage current interrupter has integral therewith a fiber optic cable extending into the housing for carrying a failure-indication signal back to a remote monitor station when current flow through the interrupter is interrupted. In the preferred embodiment described herein, the optical cable extends continuously between optical input and output ports of the current interrupter and carries a monitor signal which is continuously present during normal operation. When a fault current occurs, the cable is explosively severed to interrupt the monitor signal and thereby provide a fault indication signal to the monitoring station.

Abstract: An explosively-assisted fuse is passively triggered (without electronics) by means of an auxiliary fuse in series with the main conductor. The auxiliary fuse provides a detonating voltage across a gap formed therein on melting in response to a fault current. The auxiliary fuse is configured to facilitate sizing for a variety of current loads with a standard fuse configuration.