Hi ,

I’ve been discussing the use of Siba’s new Full-range fuse with an applications engineer
starting a new system design. He was pleased to discover that he can use a lower rated
fuse than was expected. I thought you might find this useful to know as well.

He understood that Back-up fuses need to be de-rated in transformer applications, for
example in a 100A application a 125A back-up fuse would typically be used. However, when
using Full-range fuses, there is no de-rating of the fuse value and a 100A is appropriate for
a 100A application.

I explained that in the past Full-range fuses used an inappropriate element design where
they “age” prematurely, because they operate in the fast overcurrent range area. This ageing
is due to the changing element characteristics, because of the increased power loss during
operation.

Siba’s full-range fuses are designed using a two zone design concept; each zone has a different
element. This novel design lowers power losses and inhibits temperature-rise leading to reliable
operation in both the overload and short-circuits ranges. For more details visit the Hill Tech Blog.

These ratings (datasheet) are available: