via HACKADAY: A Fuse is Just a Fuse Right?

We like to think that most common electronic components are essentially commodity items. We don´t buy premium wire or resistors. You just assume these electronic components are more or less the same from anywhere unless you need some very special characteristics. What about fuses? We would assume they are all essentially the same, but [Ham Radio A2Z] says he’s throwing away his generic fuses after he found they didn’t work as he would expect.

Of course, name-brand fuses are tested to very specific tests, and you get to see the plots of how the fuses are supposed to melt for Bussmann fuses. Then he takes out a generic assortment of fuses he bought at a hamfest. No Bussmann fuses in that batch!

Comparing the generic fuses with some from Bussmann and Littlefuse, they all work fine to carry current. That isn’t the problem. The problem is when you feed the fuses 20 A and expect them to clear. A 5 A generic fuse carried over 20 A for a very long time, and, as you might expect, it got very hot. We kept waiting for the fuse to blow, but after three minutes, he gave up.