J
John Larkin
You're not saying there is 100 year old wiring still in use?
My previous house, a Victorian built in 1892, had gas pipes leading to
all the lighting fixtures, capped off, and exposed knob-and-tube
wiring in the attic. Junctions were twisted and taped, hanging in
mid-air. I assume the original wiring was intended for lighting, and
over the years, as more loads were added, it became less suited. I had
a few joints open up, and eventually rewired it with Romex, with all
joints inside proper metal junction boxes. There's still a lot of
ancient fabric-insulated, twisted-junction knob-and-tube stuff around.
http://www.oldhouseweb.com/stories/Detailed/10327.shtml
http://www.knobandtubewiring.com/knob and tube.gif
It's common to see a fuse box, designed for 5 or 10-amp screw-in
fuses, to be full of 30's.
Around here, knob-and-tube was succeded by mandatory rigid steel
conduit and later, roughly 1960 maybe, Romex. Commercial buildings
must still use conduit, rigid metal pipe or the flexible MX stuff.
There is no requirement that old construction be upgraded, unless a
major remodel is done.
John