I remember it being 50vac to 55vac, hence...
- north american electricity (and other countries - long detailed stories) =
was originally 55 and 55 round a centre ground (long gone)
- OC for welding equipment is often around 50v, although that has changed i=
n recent years
- barriers in safety systems (non-petrochem) are often set to 50v

However, the trend these days is to limit current and time (total joules).

As to ultrscaps, as a kid I remember getting those huge can caps from old m=
ainframe PSUs (500,000uf @12v). I had fun spot welding stuff, assuming it d=
idn't vaporise (had two parts to a 3" wrench with the middle missing for th=
e longest time as a reminder).

I have known some people that could touch UK 240vac mains without feeling i=
t and known others that felt a serious shock from 9v batteries. People are =
different and electricity has different effects on them. Whilst safe workin=
g levels directives are put in place that will keep the majority safe in ex=
posed wire situations, it might not be safe for everyone.

For what it's worth, I heard the same story as Alan Peace from my uni elect=
ric machines lecturer, ex UK Electricity Generating Board guy who ended his=
 EGB tenure as a safety guy and from the southern area grid manager about t=
he same time. When I worked at a hospital the measurers in place came as no=
 surprise.=20

On 2012-02-14, at 12:17 AM, Ruben J=F6nsson wrote:

>>=20
>> 2. Approximately at what voltage does it start becoming dangerous?
>>=20
>=20
> According to IEC 61010-1 3rd edition - Safety requirements for electrical=
=20
> equipment for measurement, control and laboratory use - Part 1: General=20
> requirements:
>=20
> (not an exact quote)
>=20
> 6.3 Limit values for accessible parts
>=20
> 6.3.1 Levels in normal condition
>=20
> The a.c. voltage levels are 33V r.m.s., 46.7V peak and the d.c. voltage l=
evel=20
> is
> 70V. For equipment intended for use in wet locations, tha a.c. voltage le=
vels
> are 16V r.m.s., 22.6V peak and the d.c. voltage level is 35V.
>=20
> Voltages above those levels are deemed to be hazardous live if one or bot=
h of
> the following levels are also exceeded at the same time:
>=20
> Current levels:
> 0.5mA r.m.s, for sinusoidal waveforms, 0.7mA peak for non-sinusoidal wave=
forms
> or mixed frequencies, or 2mA d.c.
>=20
> Capacitive charge or energy:
> 45uC charge for voltages up to 15kV peak or d.c.
>=20
> 350mJ stored energy for voltages above 15kV peak or d.c.
>=20
> Other values (higher) is applicable for single fault condition.
>=20
>=20
> /Ruben
>=20
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> Ruben J=F6nsson
> AB Liros Electronic
> Box 9124
> 200 39 Malm=F6 Sweden
> www.liros.se
> Tel +46 40142078
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D
> Ruben J=F6nsson
> AB Liros Electronic
> Box 9124, 200 39 Malm=F6, Sweden
> TEL INT +46 40142078
> FAX INT +46 40947388
> ruben@pp.sbbs.se
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D
>=20
> <WPM$CTLA.PM$>--=20
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist


--=20
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View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.