In article ,
Ignoramus23561 wrote:

I had a little bit of a new experience today.

My new place has cables dropped from the ceiling, with receptacles
hanging somewhat above my height.

I was moving a crane and bumped into one of them, nothing big, just a
minor bump. Then I saw that the receptacle was on fire (or rather,
flames were coming out from inside), with small explosions inside.

I ran to the electrical control panel and turned off electricity to
the whole building. The fire stopped.

After a short while, I opened up the receptacle. It turned out that it
was full of grinding dust (! -- how did it get inside) -- and,
apparently, the dust shifted and shorted the contacts. It was a short
circuit, but with a lot of resistance from the dust, so it caught
fire, but did not trip a breaker.

I cut it off and taped the individual wires, but I am now thinking
that I need to take all of those things apart and blow them out with
compressed air.

Comments?

Sounds like a plan. And, replace any worn outlets.

But don't trust that the outlets are really off just because the
switches claim this. Old factories accumulate odd wiring and
semi-broken breakers and switches.

Before disassembly, use a voltmeter to ensure that each and every pole
is unpowered.

You may discover a breaker that also needs to be replaced.

Joe Gwinn