Re: electrical deaths

On Thu, 28 Nov 2024 14:38:41 +0100, "Carlos E.R."
<robin_listas@es.invalid> wrote:

On 2024-11-28 12:56, Don Y wrote:

 
[I worked on some systems where you had bus bars running floor to
head level.  Remove belt buckle and don't wear "riveted" jeans,
cuff links, wire-rim eyeglasses, etc.  Of course, it would be safer
just to power the beasts off when working on them but you can waste
a lot of time powering them up and down!]

>
Telephone exchanges had such bars, powered with 48 volts and huge lead
acid batteries connected to them. You could not unpower them, that would
leave thousands of clients with no service.
>
A chap of our company was working around there, on a ladder. The "false
floor" had one or two tiles removed for accessing the cables beneath. He
fell, and he of course tried to grab something to stop the fall. A
spanner was on his hand, and of course, it stuck between two copper bars.
>
It melted.
>
The entire island (Mallorca?) lost mobile phone service for an hour or two.
>
He was taken to hospital, unharmed but in shock. Maybe he had some small
burning from the hot metal, I don't remember.
>
There was an investigation, but I never knew about the results.

I have a similar story, from a colleague who had worked at one of the
big accelerators in the US Argonne National Lab in the 1960s.  He
worked in the powerhouse that provided 20,000 amps at 10 volts DC to
the accelerator field coils (which were water-cooled copper then),
delivered over a par of large copper bus-bars side by side.  One day,
he happened to drop a big steel wrench across the buss bars. The
wrench evaporated with a bang, and the power system carried on.
Startled but unhurt, he called the accelerator control room and asked
- they looked and saw no indication of that momentary short.

.<https://www.anl.gov/>

Joe Gwinn