Re: Why does laptop PSU have an earth wire?

On Tue, 21 Mar 2006 10:16:19 +0100, "John of Aix"
<j.murphy@xxxxxxxxxxxxxx> wrote:

Chris Whelan wrote:
John of Aix wrote:

So how come the rest of the world that uses two pins doesn't end up
electrocuting itself?

Sorry if this is patronising, but you did ask!

There are two methods of providing protection from accidental
contact. The first is surrounding in earthed metalwork. This is Class
1. The second method is providing insulation that is additional to
the functional insulation. Guess what? This is Class 2!

Possibly for traditional reasons, but also because supply voltages
were often lower, countries other than the UK have tended to prefer
Class 2. The variation is also related to differences is the
distribution system.

The rest of the *civilised* world doesn't use two pin plugs and
sockets, but they often use just a scraping earth type of connector
where the earth connection may not be readily seen.

My sister and a few friends have laptops from the US, two friends have
laptops from Germany, many here (obviously) have laptops from France and
not one single one of them has a three pin plug therefore no earth
to..erm..ground. Are none of them in the civilised world then (OK? I'll
perhaps give it to you for the USA ;-) )


All the french plugs I've ever had were 2 pin with an earth strip on
the edge of the plug to connect to the earth on the socket. The two
I've had for laptops were the same with a three hole connector to the
PSU. I'd assumed the earth was connected to a screen in the psu but
I've not had reason to have one stripped to find out.
.

Relevant Pages

  • Re: Why does laptop PSU have an earth wire?
    ... where the earth connection may not be readily seen. ... My sister and a few friends have laptops from the US, ... All the french plugs I've ever had were 2 pin with an earth strip on ... I've had for laptops were the same with a three hole connector to the ...
    (uk.comp.misc)
  • Re: American and British (English)
    ... laptops, everything changes, in the UK anyway. ... and therefore needs an earth and a more robust ... So the heavier three-wire connector and cable isn't confined to UK ...
    (alt.usage.english)
  • Re: American and British (English)
    ... laptops, everything changes, in the UK anyway. ... get a three-core 5 amp flex, ... and therefore needs an earth and a more robust ... So the heavier three-wire connector and cable isn't confined to UK ...
    (alt.usage.english)
  • Re: Non-magnetic screwdrivers
    ... Another alternative is, on your typical four-way mains block, to plug ... the 3-pin plug in upside-down (using the earth pin only). ... Having an external earth connector only provides any protection if both ...
    (uk.comp.homebuilt)
  • Re: Why does laptop PSU have an earth wire?
    ... where the earth connection may not be readily seen. ... My sister and a few friends have laptops from the US, ... "Some Class 2 pieces of equipment still have an earth connection to ... be for functional (eg suppression) reasons. ...
    (uk.comp.misc)