"Clive" wrote in message
...

"David Hansen" wrote in message
...
On Tue, 15 Apr 2008 18:18:08 +0100 someone who may be "Jeff"
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.


Not incorrect, some fuses have fillers in the tube to help prevent
arcing
at
EHT voltages.

Incorrect. The "fillers" (and indeed the nature of the fuse element)
are one of the determinants of the breaking capacity.


Incorrect, filling a fuse body with sand provides additional protection
against arcing in an overcurrent situation.


Only partially incorrect; the filler will have an effect on the breaking
current of the wire due to added thermal capacity, but that is not its
primary purpose, which is to prevent arcing. (the wire is gauge and
composition is modified to compensate for the filler).

Jeff