[Coco] Re: [Color Computer] Ouch!

[Gene Heskett]

On Wednesday 17 December 2003 12:32, Neil Morrison wrote:
>My all time favorite was told to me by a fellow electrician who
>worked on the first multi story building built in Wellington, New
>Zealand. Because of earthquakes, there were no tall buildings up
>until that point. He was working away on the building when there was
>the most incredible bang, followed by complete silence and all power
>going out. All the electricians headed down to the main switchboard
>room to see what had happened. It transpired that the registered
>electrical engineer who had designed the electrical system had been
>doing something to the switchboard at the far end of the busbars and
>had dropped a 10" crescent wrench directly onto the busbars. This
>turned them into an ironless motor, whereupon they all three made
>several turns destroying the pass through insulators they were
>mounted in and winding up all the take off wires attached to them,
>ripping various items out as they went, until finally the HRC fuses
>ruptured.
>
>I guess this wasn't that engineer's finest day.
>
>Neil

I can't quite top that one Neil.  The best I can do is one time when I 
was trying to file the contacts of a 600 amp zenith brand transfer 
switch, and dropped the 14" mill bastard I was using.  The switch was 
normalized and hot & I was working on the standby side contacts at 
the time.  The file went down across the hot side bars and an ounce 
or so of the file disappeared, the flash rendering me temporarily 
blind.  The fun was brought to a screeching halt by the dropping of 
the breaker handle of the buildings entrance breaker, a 1200 amp 
unit.  That was noiseier than the files demise as that puppy went 
down like a 10 gauge shotgun.

Took me about 5 minutes to find a flashlight and pick the file out of 
the now dead circuit and get a 18" crescent wrench to use on the 
handle of the breaker and reset it, all in near darkness of course.
Its a good thing I'd at least thought to disable the auto-start on the 
standby plant. :-)

It turned out that much of my problems with that transfer switch were 
caused by some danged bean counter who thought copper contacts would 
be just as good as the optional silver ones.  $5 each x 12, vs $75 ea 
x 12.

That did get fixed.

Whats the diff?  Copper welds itself together, solid silver doesn't.  
The copper contacts were welding themselves into position and the 
driving solenoid was burning up trying to jerk them open.  That 
solenoid weighed about 5 lbs, and its driving coil was about 30 turns 
of 8 gauge wire being banged by 230 volts.  If the contacts stuck, it 
was very smelly history in 1 second flat.  Normally it worked in 
about 10 milliseconds so it wasn't a problem.

[snip Daveys list of red face incidents, pretty good though :)]

-- 
Cheers, Gene
AMD K6-III at 500mhz 320M
Athlon1600XP at 1400mhz  512M
99.22% setiathome rank, not too shabby for a WV hillbilly
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by Gene Heskett are:
Copyright 2003 by Maurice Eugene Heskett, all rights reserved.