rhys wrote:
> I don't really get the concept of 'the mains here has no polarity' ........
>
> Surely the wires to plugs must be positive in one wire and negative in the
> other ( plus the earth ) ?
>
> In fact, is all wiring within the EU not standardized in terms of the
> colours for Pos / NEG / EARTH ??
>
> SO, ( if I am correct ? ) it would be possible to connect a UK wall plug
> in Portugal to the correct polarity ? And thus the fuse would be
> controlling the positive input ?

A few things need clearing up in this thread.
The same IEC colour code is used in UK and the rest of Europe. The principle colours used are Blue for Neutral, Brown for Live and Green/Yellow stripes for Earth.
Neutral is the current return to the power suppliers network. It is usually connected to the Earth at the final distribution transformer. Until 2003 Live was 220 V and the UK was 240V The supply is 50 Hz AC (alternating current), so the terms positive and negative are not relevant.
These voltages have now been harmonised and are:-
230V -10% +6% (i.e. 207.0 V-243.8 V) in most of Europe and
230V -6% +10% (i.e. 216.2 V – 253.0 V) in the UK.
These same colours are used in house wiring (i.e. the fixed wires between the fuse box and the sockets and light switches) and appliance wiring (the flexible cable between an appliance and a plug).
If UK sockets are connected to the house wiring then L should be connected to the the brown cable, N should be connected to the blue cable and E should be connected to the earth cable. If this is done then it will behave as a normal UK socket, and the fuse in the UK plug and the switch in the socket will both work on the live supply - just as they do in the UK.
Not having a ring main will have no noticable effect. The ring main is used to provide an alternative current path between the socket and the fuse box, which reduces the loading in the supply cables as the supply to the socket is shared between the two paths.
Other than meeting, or not meeting, Portuguese wiring regulations I see no problem in connecting a UK socket into a Portuguese house wiring system. (I confess that I have not read the local wiring regulations.) The physically design of the UK plugs and sockets exceeds that of the Shuko plugs and sockets used in most European countries.
As in the UK, all fixed wiring is supposed to be done by a qualified electrician. However, in my experience, these tradesmen cut corners. In both our house, and my in-laws house, Earth cables were not fitted, even to the bathrooms. The number of circuit breakers used was minimal, just one for lighting and another for power. This is despite all circuits coming back to the main fuse box. Both houses were built in the 1970´s or 80´s.

Hope this makes sense to you. If it does not, then you should definately not attempt this task yourself. Sorry to be blunt.
Alan

This does make ( mostly ) sense to me and thank you for a comprehensive summary.

I have not heard the term 'shuko' before ~care to elaborate as to what it means ?

The UK plug design has always seemed to me inherently safer than the European ones, which would be a good argument ( I would have thought ) for fitting such plugs, at least side by side with local ones, in Portugal, if local Regs do not forbid such.

By the way, I had not the slightest intention of fitting anything electrical myself, but I am also cautious about getting someone local for the reason you outline / examples you give.

Do local, Portuguese, sockets, not also require specific wiring of the blue / brown / striped cables to specific terminals ?

I never read anywhere that UK voltage had changed to 230.

I have sometimes wondered : who decided in the first place that voltage would be such and such in whatever country ? And are there advantages and disadvantages in, eg, the US where their voltage is ( I think ) 110 or 120 ? And is it direct current rather than alternating ?

rhys wrote:
> On a related issue : does anyone with qualification in electrical matters
> know the answer to the following:
>
> If one wanted to, would there be anything either (a) illegal as in
> contrary to Regulations; or (b) dangerous about having an electrician
> connect up on one's wall UK 3 pin sockets, as in, to sit alongside
> Portuguese ones ?
no problem there ,the best thing to do Is what I have done. and its cheap and safe as Portuguese use a radial system rated usually at 14 amps back at the board .
Buy a 4way UK adapter. and a 4 way Portuguese (not Chinese but from good supermarket )
Change the plug on UK unit to Portuguese and screw on wall under the original
and loop one from other giving you 3 Portuguese and 4 UK in a unit

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