Originally Posted by
thrasher
It's been years since I worked at a Co-op that had the NX fuses and blades in thier livefront padmount transformers. However I can remember one or two flashover when the fuse in the center failed. The NX are supposed to be a non-expulsion type with no fumes released, but on a couple of occasions (very rare) we found the fibreglass tube split and vent marks on the shields. Our THEORY, and that all it was, was that in rare dead faults the housing of the fuse failed and vent conductive gases across the livefront energized parts. This caused a flash to occur in the cabinent. We could never prove it and it was so rare that basically we didn't worry over it.