klem kedidelhopper wrote in message
...
On Jul 16, 9:27 am, "N_Cook" wrote:
There seemed to be grease around the Woods to avoid full mechanical
contact
to the outer casing, greenish colour so may be leaching of copper or
something. Again emphasising that the 2.5mm run of Woods if near to
melting
,
could have bent a bit while soft.
I'll have to slice open a new one (different make of course) to see if
they
are made with a knecking to the Woods
This fused one marked (doubtfully relevant as seems to be a generic
problem)
UM1 E1 X22
as well as 115 deg C and 3A

I regularly have to replace these on Eiko overhead projectors I repair
for schools. The fuse, (rated 84 degrees C), is located over and just
to the side of the projection lamp and fan motor. Typically the fan
gets sluggish or just jams up. The inside gets too hot and the fuse
opens up. It's definitely not a current thing, its a heat thing. Lenny

+++++

I opened up a new one , 105 deg C marked WTC R105, so different make and the
fusing filament in a different place. The Woods element there was a regular
flat sided bar with no observable necking.
I would still have expected all the Woods to melt , once up to its critical
temp in a heat failure mode.
But along with the spherical surface of the end of the Woods metal, in the
one in question, It would seem to be failure from heat .
Perhaps next time you come across one of your projector failures cut along
the sides of the fuse to see if all or part of the Woods melted. I should
have said the ones here are "plastic" flat-pack not the cylindrical metal
clad ones.