> Yes. In the UK, "Hot" is usually referred to as "Live", and until 1992 this was
> the official term. In 1992 the term was changed to "Line", so that the phrase
> "Live parts" could be introduced to mean any conductor connected to the
> electrical supply (i.e. not including the protective ground, which is called
> "Earth")
Shure ? Interesting, I'll avoided this term, since Erde (Earth)
seamed to me _very_ German :)
> >> >Over here in Germany only one wire is
> >> >switched and protected with a fuse, althrough it is not defined
> >> >which one is the 'hot' line, since our connector is symetrical
> >> >- there is no way to insert the plug in a way where the Hot and
> >> >the Ground side is defined - Our plug isn't inherited from the
> >> >DC times, but rather a new design when 220V AC became standard
> >> >in the 30s, to fit the needs of (and only of) AC Eq.
> Hans, I think you've gone some way to answering your own question here. See
> below.
??
> > Strange, but common - I don't know any reason why the system has
> > to be keyed, I always assumed the US development of keyed plugs
> > was triggered by old DC systems (since in DC Eq. it is necersarry
> > to know the orientation), but not a new addition. Strange, we
> > dropped all orientationwhen switching to AC (with Protective
> > Ground). Could anyone give give a reason why the system has
> > to be keyed _IF_ a Protective Ground is included (other than
> > define the Protective Ground pin) ? Because, without Protective
> > Ground a definition of Neutral is essential, but with, no longer.
> Because the fuse and/or switch _in the equipment_ has to be on the hot/live side
> of the supply. Otherwise a blown fuse - because of a short circuit - could
> leave the equipment with the hot supply still connected to whatever shorted out.
> Which could be the chassis...
So, now just tell me why our system works great, where the _inner_ fuse
is randomly asserted to Line ore Neutral - shure, your example fits, as
long as the chassis is not wired to Earth (Protective Ground) - but as
soon as it is, and there is a (possible harmfull) connection betwen the
Line wire and the chassis, the regulat (outside) fuse will go off.
In fact the _inner_ fuse is/was never ment to secure the user, but rather
the Eq. (implicietly also the user, because if the something would overheat
a fire would also cause harm to the user).
> Also, at least in the UK, some old equipment had neutral solidly bonded to the
> chassis and no protective ground. This is common on valved (tubed) radios and
> things. ISTR that here the fuse was generally on the chassis side, so that when
> the fuse blew, the chassis would no longer be connected. Still not really safe,
> since the chassis would be connected to the other side via the heaters of all
> the valves, and these typically pass 100mA to 300mA at mains voltage, or more if
> they're cold.
Not over here - since the general AC system was introduced the connector
was always flipable (not polarized) and no connection was allowed inside
the device between Neutral and any user touchable part. The connection
between Neutral and Earth was always done in the fixed part (eg. in the
outlet in early times).
Gruss
H.
--
Stimm gegen SPAM: http://www.politik-digital.de/spam/de/
Vote against SPAM: http://www.politik-digital.de/spam/en/
Votez contre le SPAM: http://www.politik-digital.de/spam/fr/
Ich denke, also bin ich, also gut
HRK
Received on Tue Apr 20 1999 - 16:00:59 BST