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7 Sep 2024 09:22:22 EDT (-0400)
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From: Stephen
Subject: Re: Research
Date: 14 Oct 2008 08:25:01
Message: <web.48f48e84bc894529208d05c80@news.povray.org>
Invisible <voi### [at] devnull> wrote:
> Stephen wrote:
>

> > do :)
>
> Isn't that illegal?
>

Yes and not very effective.


> > 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."

Is it not to protect the church from the devil ;)
A bit like a high tech gargoyle.


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From: Tom Austin
Subject: Re: Research
Date: 14 Oct 2008 08:31:10
Message: <48f4910e$1@news.povray.org>
Stephen wrote:

> 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.
> 

I am not an electrician, so I know enough to be dangerous.
Actually, I studied electrical engineering - so I know enough to keep 
mostly safe.

I was thinking I would write about keeping a hand in the pocket, but you 
beat me to it.

I always have a hand in my pocket when routing wires in my main electric 
panel where I can't easily turn everything off.  It isn't enough to just 
keep a hand away - by instinct you will use it to grab on to something.



I've been lucky, I've never been hit with anything more than 110v


Tom


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From: Tom Austin
Subject: Re: Research
Date: 14 Oct 2008 08:34:31
Message: <48f491d7$1@news.povray.org>
Warp wrote:
> 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?
> 

Some non-electricians will hook up the earth as a common - using it as 
the return path for the hot.

In this case the potential will vary with the amount of current on the wire.


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From: Stephen
Subject: Re: Research
Date: 14 Oct 2008 09:00:00
Message: <web.48f496a4bc894529208d05c80@news.povray.org>
Tom Austin <taustin> wrote:
> Stephen wrote:
>
> > 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.
> >
>
> I am not an electrician, so I know enough to be dangerous.
> Actually, I studied electrical engineering - so I know enough to keep
> mostly safe.
>
> I was thinking I would write about keeping a hand in the pocket, but you
> beat me to it.
>
> I always have a hand in my pocket when routing wires in my main electric
> panel where I can't easily turn everything off.  It isn't enough to just
> keep a hand away - by instinct you will use it to grab on to something.
>
>
>

I get nervous working over 5V Vcc.

reason I stopped working offshore. It was getting too dangerous.


waistband.


> I've been lucky, I've never been hit with anything more than 110v
>
>
A mere tingle :P
240 V is not too bad it hurts more but is bearable if it is just through your
hand. And most of the shock is just shock people do get used to it and can even
deliberately touch live connectors to test the voltage. The trick is to do it
fast and the pain level will tell you the voltage. The same way that I learned
to see how close to boiling water is by dipping my fingers into it (FAST). The
human body is very resilient.


Stephen


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From: scott
Subject: Re: Research
Date: 14 Oct 2008 09:43:42
Message: <48f4a20e@news.povray.org>
> Some non-electricians will hook up the earth as a common - using it as the 
> return path for the hot.
>
> In this case the potential will vary with the amount of current on the 
> wire.

But I think that Buildings Standards require that the resistance to ground 
be low enough that for the Earth voltage to become dangerous, enough current 
must flow to blow a fuse.  Otherwise this kind of relatively common fault 
would leave metal cases of everything in the house electrified to dangerous 
voltages!


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From: scott
Subject: Re: Research
Date: 14 Oct 2008 09:52:26
Message: <48f4a41a$1@news.povray.org>
> Yeah, some bathrooms have special "shaver" sockets which are weird 2-pin 
> connectors fused at 2A or something. Personally, I don't know about you, 
> but my bathroom is so tiny that you'd be just as well to go somewhere 
> else... ;-)

It appears that the forthcoming 17th editiion of the building regulations 
(aren't you excited!) in the UK will allow normal 13A sockets in a bathroom, 
if they are protected by a 30mA RCD and not too close to a shower/tap...


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From: Invisible
Subject: Re: Research
Date: 14 Oct 2008 09:54:40
Message: <48f4a4a0@news.povray.org>
scott wrote:

> It appears that the forthcoming 17th editiion of the building 
> regulations (aren't you excited!) in the UK will allow normal 13A 
> sockets in a bathroom, if they are protected by a 30mA RCD and not too 
> close to a shower/tap...

How in the name of God do you know that? o_O


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From: scott
Subject: Re: Research
Date: 14 Oct 2008 10:30:50
Message: <48f4ad1a@news.povray.org>
>> It appears that the forthcoming 17th editiion of the building regulations 
>> (aren't you excited!) in the UK will allow normal 13A sockets in a 
>> bathroom, if they are protected by a 30mA RCD and not too close to a 
>> shower/tap...
>
> How in the name of God do you know that? o_O

My mum asked me a while ago about putting a socket in her bathroom, so I 
looked into it then.  It appears that now you are actually allowed normal 
sockets in your bathroom (Wikipedia was a bit out of date).


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From: Gail
Subject: Re: Research
Date: 14 Oct 2008 10:35:48
Message: <48f4ae44@news.povray.org>
"scott" <sco### [at] scottcom> wrote in message news:48f4a20e@news.povray.org...
>> Some non-electricians will hook up the earth as a common - using it as 
>> the return path for the hot.
>>
>> In this case the potential will vary with the amount of current on the 
>> wire.
>
> But I think that Buildings Standards require that the resistance to ground 
> be low enough that for the Earth voltage to become dangerous, enough 
> current must flow to blow a fuse.  Otherwise this kind of relatively 
> common fault would leave metal cases of everything in the house 
> electrified to dangerous voltages!
>

I've seen similar happen in an old flat I was renting at University. Don't 
know how it happened (not an electrician), but something in the geyser 
shorted and left all of the hot water pipes (and the water) live.
It's times like that when having a friend who's father works for the city 
council as an electricial comes in handy.


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From: Stephen
Subject: Re: Research
Date: 14 Oct 2008 10:55:38
Message: <fmc9f4pkj88li0q4l0b7v29i8psv80mo6r@4ax.com>
On Tue, 14 Oct 2008 07:38:36 +0100, Orchid XP v8 <voi### [at] devnull> wrote:

>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. ;-)

True
-- 

Regards
     Stephen


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