Full range current limiting fuse having high load current carrying

Abstract

A current limiting fuse is provided with a number of discrete current limiting elements coupled electrically in parallel between a pair of conductive terminals, and a fused gap assembly in series with each current limiting element whereby full range fault current protection is provided by the fuse. Under the influence of high range fault currents, the current limiting elements operate collectively to quickly clear the fault, while low fault currents are interrupted by fusing of the fused gaps to present a plurality of parallel arc gaps in the elements, which parallel gaps function in turn to sequentially distribute the full fault to each element resulting in successive interruption by the elements and ultimate clearing of the low range fault. In a second form of the invention shiftable contact sets in each element are operably coupled with a low fault current responsive device to create the arc gaps required for sequential operation of the current limiting elements.