Dan Masters writes: (Edited for bandwidth preservation)
<<<<<<<<<<<<<<<< Snip >>>>>>>>>>>>>>>>>>>>>>>.
This gets us then to the rating of the Lucas fuses. According to the Haynes
manual for the MGB, the 35 amp Lucas "...fuses are 17 amp current rated, 35
amp blow rated." What does that mean? Well, not being a fuse expert, I'm
going
to have to take a guess, but I assume that over a long time period, current
"around" 17 amps will blow the fuse, and 35 amps will blow it
instantaneously.
By comparison, a 35 amp American fuse will handle current very near 35 amps
indefinitely. I don't know how much it would take to blow it instantly, but
it
would be a lot more than 35 amps, and certainly a lot more thean the wiring
in
a Triumph is rated for.
<<<<<<<<<<<<<<<<<<< End Snip >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
I'm not a fuse expert either but I have spent some time sizing fuses and
circuit
breakers and I can tell you that here in the US of A when the manufacturer
rates
a fuse at 20 amps it means that it is guarrnteed to not blow at 20 amps and
it is
guaranteed to open at 40 amps and may or may not blow anywhere in between.
The time it takes for a fuse to open is an inverse function of the current
that flows
through it and the difference between a slowblow and a fast acting fuse
(there
are several types of each) is the time scale. A fast acting fuse will open
in 1/2 to
1 second at twice rated current whereas a slowblow fuse will blow in about
10
seconds.
Lucas fuses, on the other hand, seem to be rated according to the amount of
current that it takes to open up. This is why the new ones you see are
rated at
"17 amps carry and 35 amp blow".
Hope this trivial knowledge helps.
Dave Massey
St. Louis, MO USA
57 TR3
71 TR6
80 TR8
|