"David Hansen" wrote in message
...
On Tue, 15 Apr 2008 11:16:45 +0200 someone who may be "Clive"
wrote this:-

The physical size of the fuse IS important when you are considering
spark-gaps etc, which is what caused the dramatic failure in this case.

Incorrect. What is important in this respect is the breaking
capacity of the fuse. Different designs of fuse, with the same
physical dimensions, are able to reliably break different currents.
The same is true of different designs of miniature circuit breaker.


Depending on the voltage and not the current !

From the OP's description, the voltage was high enough so that when the fuse
blew, the air gap was insufficient to stop a spark forming, hence ionizing
the air in what had been the fuse housing causing the fuse holder to
disintegrate. In this case, it seems that the fuse was physically (and not
electrically) too small to stop this happening, regardless of the current.

//Clive.