ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Extension cords

Yes, I suppose some updates are in order, although most of the posters on this thread are gone now.

1) Italy and France seem to be the only countries that have plugs that are compatible with Euro plugs but have a higher rating (6 A in France, 10 A in Italy). That's what sometimes ends up on cheap hairdryers, although I've seen at least one 1500 W hairdryer with a plug clearly marked "2.5 A 250 V". We also have one with a truly strange plug, the pins are exactly the same thickness as on a Euro plug but considerably shorter - I need to replace that one as soon as possible!

2) VDE now requires all extension leads (except those that only accept Euro plugs) to be 1.5 mm2 or larger, apparently there were too many issues with overheating 1 mm2 power strips.

3) There are extension leads with contour plugs and mating sockets that have plastic "walls" in place of the earth scrapers that should in theory exclude Schuko/French plugs but in reality they break easily. I'm not sure if they even comply with Austrian and German regs but they're sold. Usually they're undersized too, 1 mm2 and up to 20 m long. Fairly popular among contractors of Eastern European descent.

4) Earthing arrangements in Hungary, Slovakia and the Czech Republic (actually that deserves its own thread but I'll quickly comment on that here): some older places in Hungary have sockets for class-0 appliances but it seems they were banned for new work some time in the 60s or 70s. All earthed supplies seem to be TN-C-S with the PEN split near the supply fuses, although there might be TT supplies in rural areas. Old wiring is - scary enough - 1.5 mm2 Al in conduit or cable buried in the walls, in the 1980s they went up to 2.5 mm2 Al. Joints seem to be twisted and taped everywhere, even with newer copper mixed in.

In Czechoslovakia I've never seen a socket without earth, most houses seem to have been rewired at some point. However, all the older installations are TN-C, often wired with Al. A friend's apartment in Prague had 2.5 mm2 Cu socket circuits (two doubles per room) and 10 A lighting circuits wired with a wild mix of 1.5 mm2 Cu and 2.5 Al. I've also seen socket circuits with 4 mm2 Al. Aluminium wire seems to have been widely used in Europe during WWII due to material shortage but most, if not all countries behind the Iron Curtain continued using it into the early 1990s. Apparently in Latvia Al wire was readily available in DIY stores in the early 2000s.

Finally a note on pre-Schuko sockets and plugs (i.e. un-earthed for class-0 appliances): the original design was 6 A with split 4 mm pins and 4 mm holes on the sockets. Later, a 10 A design with 4.8 mm solid pins and corresponding holes on the sockets was introduced. Apparently 10 A plugs were fairly common in Germany but rather rare in Austria but most, if not all new sockets from the early 1950s onwards were 10 A. New installations were required to be fully earthed by 1958 with a transitional phase (for buildings already in planning or under construction) until 1960 but un-earthed sockets were sold as replacements or for extensions of existing installations well into the 1970s. Leftovers could be found in older stores as late as 1990.

A brief explanation on class 0 and un-earthed sockets: class-0 appliances are designed like class-1 appliances with only one protective layer between live parts and exposed metal casings. They were only to be used in "isolated rooms" with no exposed earth potential, e.g. earth wires from either mains wiring or radio/TV aerials, metal water, gas or central heating pipes, stone floors etc. The reasoning was that under these circumstances people could not possibly receive a fatal shock from a faulty appliance since there is no path to earth for a current to flow. This is the main reason why those old plugs don't fit Schuko sockets but vice versa - in an isolated room a class-1 appliance without earth is no more dangerous than a class-0 appliance. In some countries isolated rooms were used much longer than in Austria and Germany, e.g. in Sweden until 1994.