🚀 go-pugleaf

"Whiskers" <catwheezel@operamail.com> wrote in message 
news:slrnghjjbg.e5j.catwheezel@ID-107770.user.individual.net...
> On 2008-11-11, Arfa Daily <arfa.daily@ntlworld.com> wrote:
>>
>> "Whiskers" <catwheezel@operamail.com> wrote in message
>> news:slrnghja8j.e5j.catwheezel@ID-107770.user.individual.net...
>>> On 2008-11-10, Dave Plowman (News) <dave@davenoise.co.uk> wrote:
>>>> In article <slrnghhb1o.bes.catwheezel@ID-107770.user.individual.net>,
>>>>    Whiskers <catwheezel@operamail.com> wrote:
>
> [...]
>
>> A system carrying a lot of amps to the load that's drawing it, is no more 
>> or
>> less dangerous than one that's only carrying a small current, except in 
>> as
>> much as there is a greater potential for heat failure at connection 
>> points
>> within that system. A high voltage system, irrespective of how many amps 
>> it
>> is capable of carrying above a few milliamps, is far more dangerous to a
>> human, than a low voltage system good for a few hundred amps. Given the
>> (reasonably) constant resistance of any described path through the human
>> body, a voltage of a hundred volts with a current availability of as 
>> little
>> as 50mA, may be enough to kill under the right (wrong!) circumstances.
>
> So a charge of 10kV from walking across a carpet (DC) , or a "non-lethal"
> 50kV "Tazer" (AC), are more dangerous than a 1kV power line?  The danger
> from 'High Voltage' power lines comes from the vast amount of current they
> can deliver.
>

See:

http://en.wikipedia.org/wiki/Electric_shock

and scroll down to "Lethality of a shock".

From the table there it is apparent that passing a current anything over 
about 0.1A is quite likely to be fatal, so it makes little difference 
whether the voltage source is capable of supplying 1A or 1000A.

The lethality of any voltage source that can supply more than about 100mA 
will depend on there being sufficient voltage to pass lethal current through 
the body according to Ohms law (V/R=I).

Typical estimates for human body resistance:

Unbroken dry skin = about 100,000 - 500,000 Ohms
Unbroken wet skin= About 1000 Ohms
Broken skin= As low as 100 Ohms

The higher the voltage, the greater the likelihood that localised burning 
will break the skin resulting in a rapid drop in resistance with consequent 
increase in current flow.