Fuses and branch circuits

[Andrew Gabriel]

Why are some fuses not rated for use on branch circuits? I'm looking at
using a 3 amp midget fuse and it says "not designed for branch circuit use".

The answer in the UK is that branch circuit fuses (BS1361)
have a higher breaking capacity (16.5kA) than fuses used on
appliances (BS1362, 6kA).

So if you used a BS1362 fuse in a branch circuit which had a
prospective short circuit current greater than 6kA, then the
fuse might fail to break the current flow on a short circuit
resulting in serious damage (or fire) in wiring, and/or the
fuse might explode damaging the holder, because you are
exceeding its breaking capacity.

I don't know for sure if the reason in your case is the same.

 

[Jim]

Why are some fuses not rated for use on branch circuits? I'm looking at
using a 3 amp midget fuse and it says "not designed for branch circuit use".

Thanks.