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"Warp" <war### [at] tag povrayorg> wrote in message
news:48f38551@news.povray.org...
> Orchid XP v8 <voi### [at] devnull> wrote:
>> Nope. As the Wikipedia article explains, there are sprung-loaded plastic
>> covers that only move out of the way as the earth pin is inserted.
>
> Is it guaranteed that the difference in potential between the earth pin
> and the physical ground is always very close to zero?
>
> Because AFAIK there may be surprisingly large potential differences
> between the earth pins of neighboring buildings at some places.
When I was at university, there was a noticable potential difference between
the earth pins on different floors of the same building. It played hell with
the coax network cable...
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"Darren New" <dne### [at] sanrrcom> wrote in message
news:48f381e2$1@news.povray.org...
> Gail wrote:
>> Next thing I was sitting with my back to the wall of the server cupboard
>
> Wow. I'm glad we only use half the voltage here. I've been shocked a few
> times in the US, and while it leaves you shaking a bit, I can't imagine it
> being bad enough to knock you down.
It didn't really. I was sitting on the floor fiddling with the server. It
knocked me back about half a metre
When I said server cupboard, I meant it. It was a 'room' about 2.5 m long
and just over 1 m wide
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Gail wrote:
> When I said server cupboard, I meant it. It was a 'room' about 2.5 m
> long and just over 1 m wide
Gee, that sounds just like *my* server room...! o_O
Tell me, is it also freezing cold in there?
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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Orchid XP v8 wrote:
> ...which reminds me of the time I stood on an upturned BS1363 plug,
> barefoot.
>
> Trust me, it hurt.
>
> It hurt *almost* as much as a split second later, when I grabbed a
> red-hot gas fire griddle to support myself as I hopped around in pain.
>
> I had a griddle pattern on the skin of my hand for, like, a month after
> that...
>
...
Dear god.
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Nicolas Alvarez wrote:
> ...
>
> Dear god.
...and *then* everybody was mad at me for yelling my head off at, like,
6 AM on a Sunday. O_O
I mean hell, if you spiked your foot and then burned your hand, would
*you* care what time of day it is???
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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On Mon, 13 Oct 2008 21:26:05 +0200, "Gail" <gail (at) sql in the wild (dot) co
[dot] za> wrote:
>
>"Darren New" <dne### [at] sanrrcom> wrote in message
>news:48f381e2$1@news.povray.org...
>> Gail wrote:
>>> Next thing I was sitting with my back to the wall of the server cupboard
>>
>> Wow. I'm glad we only use half the voltage here. I've been shocked a few
>> times in the US, and while it leaves you shaking a bit, I can't imagine it
>> being bad enough to knock you down.
>
>It didn't really. I was sitting on the floor fiddling with the server. It
>knocked me back about half a metre
You probably threw yourself back and it wasn't the electric shock. Working in
the business I have had more shocks than I can remember from 110 Vac tingles to
a 660 Vac wallop from a 3 phase distribution board. The most painful was when a
loose strand of wire pricked my finger with the power off and I hurt my hand
against the case getting it out of there. I knew the power was off but try
telling that to your reactions :)
I once got a 500 Vdc belt that lifted my feet off the ground even though I was
standing on a rubber mat and wearing insulating boots. As we all know ac throws
you off and dc makes you grab on so it was a reaction that made me jump
incidentally breaking the contact with the supply. It sure does waken you up ;)
Here are a couple of tips for everyone when working on live equipment. Wear
insulating footwear and keep one hand in your pocket. That way the current is
less likely to find a path through your body.
Incidentally when you see medics using that "Stand Clear, Stand Clear" electric
defibrillator. They are not starting the heart but stopping it. Think on :)
--
Regards
Stephen
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Stephen wrote:
> Incidentally when you see medics using that "Stand Clear, Stand Clear" electric
> defibrillator. They are not starting the heart but stopping it. Think on :)
It's like rebooting a computer. Gotta shut it down to make it start back
up again in normal working order. ;-)
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
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>> Nope. As the Wikipedia article explains, there are sprung-loaded plastic
>> covers that only move out of the way as the earth pin is inserted.
>
> Is it guaranteed that the difference in potential between the earth pin
> and the physical ground is always very close to zero?
The Earth wires in your house (in the UK at least) are connected to the
physical ground at your house, usually by being connected to the mains water
pipe or some similar big lump of metal in the ground. So I don't think
there can be much of a difference, there is probably some building standard
that gives limits on the resistance. I assume these limits are set so that
any potentially dangerous Earth voltage would result in the current in the
defective device blowing a fuse.
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"scott" <sco### [at] scottcom> wrote:
> >> Nope. As the Wikipedia article explains, there are sprung-loaded plastic
> >> covers that only move out of the way as the earth pin is inserted.
> >
> > Is it guaranteed that the difference in potential between the earth pin
> > and the physical ground is always very close to zero?
>
> The Earth wires in your house (in the UK at least) are connected to the
> physical ground at your house, usually by being connected to the mains water
> pipe or some similar big lump of metal in the ground. So I don't think
> there can be much of a difference, there is probably some building standard
> that gives limits on the resistance. I assume these limits are set so that
> any potentially dangerous Earth voltage would result in the current in the
> defective device blowing a fuse.
do :)
In new builds you will often find a metal rod driven into the ground as an
earthing electrode.
--
Stephen
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Stephen wrote:
> do :)
Isn't that illegal?
> In new builds you will often find a metal rod driven into the ground as an
> earthing electrode.
"I think having a lightning conductor on a church represents an
extrodinary lack of faith."
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