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?

i


Igor,
I think it would be wise to check all the electrical boxes and outlets
in the grinding area and maybe a couple in the rest of the shop away
from the grinding area to see if they are contaminated. If there is
that much grinding dust in the outlets, think how much was breathed in.
If you had 480 in the box it probably would have exploded. The call
that arc flash.

John