John Fimognari wrote to PICLIST (and somehow got my address in the
"Reply-to" field!):

> I have a feeling that Aus copied or imported the SAD plug design from
> the USA in the 1930's. I have seen it in old USA catalogues listed as
> a 220volt special plug.

  Quite possibly.  We must have copied one of the better things then, as
they are completely standard here and have no obvious problems.

> The shrouds around the extension cable sockets were introduced because
> the thickheads in the building industry were always dropping the
> extension leads into water.

  I don't quite see the (pun!) connection?

> The 15amp plug pins and sockets and rocker switches are made of
> different material than the 10amp version.

  That might account for the pins being the same size.

  And from Morgan Olsson:

> Is there also a compatible live + neutral only   / \  ?

  Indeed.  Makes a nice compact plug for double-insulated appliances.
Note it is still polarised so the switch can be kept in the "live" side.

> Is there a reliable standard for *which* one is the live?

  Yes (nowadays!).  Earth, Neutral, Active (Convention; clockwise
looking at the plug pins).

> Is it specified for the polarised Shuko?

  Hey, I'm not the expert here!  It would appear to be.

> For the "apparatus connector" IEC320 found on back of PC:s and other
> electronic appiances, is it specified which one is neutral?

  Definitely; it's embossed on the separate connectors.  It happens to
be the reverse of the above sequence.

> It would really be nice if also the 2 pin Neutral + Live connectors
> are polarised, so the floor lamp, when we shut it of by the switch, it
> is guaranteed to be no voltage when we change the bulb.  Now we have
> to move the sofa to pull the plug if we are careful.  (I do it since I
> was changing a bulb in a floor lanp, and the lamp socket broke to
> pieces...)

  I won't comment.  We have predominantly bayonet cap lamp fittings in
domestic use.

  Oh, let me explain something about our "sad" plugs.  The earth pin is
slightly longer so it contacts first and separates last as indeed it
does in most standards.  Having the earth on the bottom further means
that downward pull on the cord tends to seperate the "power" pins first.
The tangential alignment of the "power" pins means that they are further
separated from the skirt of the plug than they would be if radial and
thus more difficult to touch by accident.  This is equally true of the
two-pin American fittings.
--
  Cheers,
        Paul B.