Self life of fuse

Shelf life?

I am afraid there are way too many variables to take into account with the life of a 'bit of wire'...

Take the ambient temperature, the peak current, the average current, vibration, mechanical stress etc...

All of the above will reduce the life of a fuse, many people think a fuse will last forever if the current is below it's rating, but it won't.

I would have a chat with the technical people at the manufacturers, but I don't expect they will be able to help without the above information...

John.

If the fuses are for higher current applications, could the fuse holders themselves be weak ( meaning not gripping the fuse tight) or slightly burnt/corroded as to build up heat and "falsely" blow the fuse?

If they are low current for electronics protection, I'd be looking for some strange transients blowing the fuses. I've never heard tell of "age" prematurely killing a fuse.

I know where there are fuses still in service that are easily 60 years old.

Are these a very special type of fuse?

In general, if fuses are sized such that their rating is close to the average current they conduct, they "age", and when it is much higher, they don't.

In other words the closer a fuse is used to its rating, the more likely it is that it will fail at some point. Many fuses, while normally conducting below their rating, experience brief surges that are well above that, as in for example a 15 Amp fuse in an incandescent lighting circuit of 13 Amps or so, or a motor starting circuit in which case "Slo-Blo" fuses would be called for.

There are a number of factors involved in proper fuse selection, so there is no simple answer other than that fuses can "age".

Greg

Fuses don't like moisture.

Current surges or spikes can and will begrade the fuse element over time (both dependent on each other), altering its characteristics somewhat. Have you monitored the line current to see if this is happening?