"Larry Jaques" wrote in message
news
On Thu, 9 Nov 2017 19:04:55 -0500, "Jim Wilkins"
wrote:

...
I built a test load for a 48V 1000A central office battery charger,
to
replace an old wood-framed one that had burned up. I didn't tie down
all the 4/0 welding cables for the initial test and when we switched
it on the suddenly magnetized cables slamming into the metal frame
sounded like lightning had hit the building.

I'll bet the janitor had to sweep up a whole lot of buttonholes that
evening.

Everyone was used to the high noise level of a sheet metal fab shop.