Arcing fault and arc flash protection system having a high-speed switch

Abstract

A high-speed arc terminator for an electrical power distribution system includes a sealed, evacuated housing, and a controllable mechanical switch having first and second electrically conductive contacts enclosed within the housing and adapted to be coupled to the power distribution system outside the housing. A trigger conductor extends into the housing and has an exposed end near the gap between the contacts when the contacts are in the open position. At least one of the contacts is movable between an open position in which the contacts are separated by a gap, and a closed position in which the contacts engage each other, and an operating mechanism is provided for moving the at least one contact between the open and closed positions. A high voltage source is controllably coupled to the trigger conductor for supplying a high-voltage pulse to the trigger conductor in response to the detection of an arcing fault. The high-voltage pulse produces an arc within the gap between the contacts, to shunt fault current from the power distribution system across the gap, from one of the contacts to the other, before the contacts engage each other.