This may be semi OT as it is electrical, not electronic.
I work as a stationary engineer for a municiple government. Part of
our duties is minor electrical work - things like changing lamp
ballasts, fixing broken outlets, changing electric motors etc.
Anyway, I got a work order this morning saying that one corner of a
florescent fixture was pulling away from the ceiling in a preschool
room.I looked and one corner was sagging down about 1/4". I grabbed
a ladder and went up to see what was happening. I touched the
fixture and *ZAP*. Not a big jolt, but my fingers were a bit numb
for 15 minutes or so.
Needless to say, the power went off REAL fast after that. I took the
lens off, the tubes out, and removed the ballast cover. First thing
I noticed was the lack of a ground wire... Not a loose ground - it
was completely missing!
Next thing I noticed was that the knockout was bare. No bushing was
installed at all! I grabbed the hot and sure enough, the sheet metal
had cut through the insulation and charged the entire fixture to 120
volts - WITH NO GROUND. Thankfully, I was using a wooden ladder and
had touched a painted portion of the light.
It doesn't end there either. I took the fixture completely off the
ceiling and in the process discovered that the installer had simply
used metal screws directly into acoustic ceiling tiles! No joists
above, no toggle bolts, not even stupid drywall plugs. What boggled
my mind was that this fixture had been there for at least 12 years
(as long as I've worked there). And the room above this is a
gymnasium. When people run around, the ceiling shakes so much that
aluminium angle was screwed onto the fixtures to keep the lenses
from falling out.
Still not finished! The junction box was 6" to the side of the
knockout they used so the wires were sandwiched between the ceiling
and the fixture then had to do a 90 through the (unbushed) knockout.
The junction box itself was not attached to anything. It just had a
piece of wood screwed to it so it wouldn't fall through the hole in
the ceiling tile.
As you probably guessed, yes, most of the wires are NOT in conduit,
they were just run along joists with staples. There was one wire in
conduit, which simply ended and the wire then did a 100 degree turn
and got fed into the junction box.
There were three sets of wires led into the box - each with a
ground. All of them were neatly wire nutted together... NOT attached
to the junction box OR the fixture.
I looked around the room, there are 12 other fixtures... Needless to
say, the big boss, the medium boss, the little boss, and everyone in
between has heard about it. That room is a death waiting to happen.
Moral of the story - NEVER "make do" with wiring. If you're going to
use dangerous voltages in your projects, DO IT RIGHT or scrap the
project. The person you kill may not be yourself.
