Fuse Breaking Current: Explained

[adool_617]

Dear all , i have an important question which i need answer for it , if you look at a catalog for fuses you will find the fuse rated current which for example is 10 A

and you will find a value called minimum breaking current and it is usually higher than the rated current for our example let's say about 15 A

so what is meant by minimum breaking current , does it means the fuses will not disconnected
unless a value higher than or equal 15 A which is higher than the normal rated current .

and what will happen if a continuous current flow for a long time with value 13 A which is higher than the rated current and smaller than the minimum breaking current

please help

thanks

 

[SirAskalot]

Low test current (I₁) is defined as; the largest current the fuse can hold for one hour without breaking.
High test current (I₂) ; the lowest current which breaks the fuse within one hour.

Not quite sure what minimum breaking current is, but i believe it must be I₂. Not sure though, someone else might know.

If you se a graph like http://www.buildingdesign.co.uk/elec-technical/hager-t1/18-hager-4.gif" . I₁ is 1.13A and I₂ is 1.45A in a 1A fuse.

 

[adool_617]

well , actually after doing some search i found this:
the minimum breaking current is the minimum current that can cause the fuse to disconnect
for example assume the normal current for a fuse is 10 A and the minimum breaking current is 15 A , so between this region the fuse cannot completely trip or disconnect so when you choose the fuse you must make sure that you are not going to work in this region .