View Single Post
  #86   Report Post  
Old April 15th 08, 08:01 PM posted to uk.railway,uk.rec.subterranea,uk.transport.london
Bill Again Bill Again is offline
external usenet poster
 
First recorded activity at LondonBanter: Feb 2007
Posts: 12
Default Crossing London tube tracks


"Jeff" wrote in message
. com...

"
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. Fuses will normally have a voltage rating as well as a
current rating and type (fast blow, anti surge etc.)

Jeff


Even these little household fuses are filled with sand to do exactly that
job.