"Bob Nuckolls recommends fusible links, so that is what I will use in
future. I've yet to read anything of his that I can't respect and he's
brighter than me anyway. Graham"
Can I join your group? I think it's pretty large and I know I
qualify.
There is another reason why I won't use switch-breakers or
whatever those "automatic" C/Bs are called - nor would i prefer to have
handy the pullout C/Bs so beloved of airline engineers.
I shared an article about C/Bs several years ago. It discussed
the propensity for danger in the wire used since the 80's - the tefzel
covered stuff. It has a habit after vibration, moisture and heat (admittedly
not so intense in most of our milieus) of cracking. Again this occurs
geberally after a number of years. What happens is the teeny cracks open to
moisture, the wire carries too much current and the C/B pops open. That's
good.
` What prompts the danger is pushing the offending button back in
to see what happens, time two. That's bad. What happens is the surge bak
into the circuit prompts a tiny but hot spark which overheats the tefzel
locally and "turns it into fuel". In some cases it explodes enough to blow
apart adjacent lines - not a good thing. Nor perhaps is it exactly
applicable to our operation.
Give me fusible links (a la Nuckolls) or give me fog. As Bob N
says, "make a case for getting along without it because you've got a
backup", then just get along without it till you're on the ground.
Don't turn it on again to see what happens. It might.
Cheers, Ferg
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