Fuse Cartridge 1Time Bld 100A For general purpose circuits, protects lighting, heating and other circuits not subject to temporary surges and where available short-circuit currents are relatively low. Does not have any appreciable degree of time delay and should not be specified in ci rcuits where large transients or motor overloads occur. Single element type. The counterpart of type W plug fuses. Use in non-motor circuits. 50,000 AIR. 250 volt maximum. UL Listed.