European Plug Standards

We don't need exact polarity between the hot and neutral wire.

The reason there's no standard is that most Europeans consider what their own country uses to be significantly superior to what other EU countries use. On probing further, you'll find they don't actually understand the issues in other countries, nor even their own in many cases, but that doesn't stop them being experts of course.

The standardisation has in effect happened at the other end of the power cord, i.e. the IEC mains inlet connectors on appliances.

Curious why? I can't see any difference between the grounding arrangements of Shuko or any of the other grounded connectors in use. It does have a problem of being able to fit into some ungrounded outlets in some EU countries, thus enabling an appliance which needs grounding to run with the ground disconnected. In some other EU countries, the view is taken that in an earth-free room, there is no requirement for Class I (earthed metal cased) appliances to be grounded. In the UK and some other EU countries, that would be very strictly forbidden.

Yes, the plug can be plugged in either way round. There's no polarity in the French/Belgium socket outlets either -- although the plug cannot be reversed in the socket, it is not defined which contact is the live and neutral, and in double outlet sockets and

2-way adaptors, you virtually always find the two sockets hardwired the opposite way round.

There isn't any concept of "the Euro System". Polarity is quite important in the UK (and probably other countries which have also guaranteed it for ~80 years) as many appliances make assumptions they will be connected with the right polarity. Examples are fusing in the live conductor only, switching in the live conductor only, and appliances designs which won't operate correctly if live/neutral is reversed because correct connection is guaranteed.

The supply infrastructure used in different EU countries is not all the same either. 1 hot, 1 neutral, 1 earth is common, but it is not universal. Some areas of some countries have neither main conductor near earth potential (in which case any concept of polarity of connectors is rather meaningless). Some countries provide 3-phase supply to most residences. (In the UK it's available if you want it, but you don't have to have it unless you want more than 100A supply. In some other EU countries, the max single phase supply is 20A, so just about everyone has a

3-phase supply.)

The socket style/type is only one aspect of the issue. Different supply systems in use don't make sense with some of the other socket outlets in use. Protection against overloads and faults is another issue, and where such protect is provided.

I would use the UK system. High quality parts are available cheaply in most regions of the world as it is now widely deployed in many countries. It was designed from scratch post-WWII which makes it one of the newest designs in use, and didn't evolve with various compromises which you find in some other systems. Of course, I come from the UK;-)

I would pick 230V. The high current, voltage drop, and supply sags common on 120V circuits are something we don't have to put up with in 230V countries. Filament lamps work more efficiently at 120V, but they are last century's technology.

I don't have a view.

Well, is there any improvement in safety when one wire is essentially at earth potential?

In the US, for example, most plugs are polarized. The appliance is USUALLY wired so that the "hot" lead is switched and the "neutral" lead is connected all the time.

HOWEVER, when I took apart a DVD player than failed (they aren't worth fixing) I noticed that it has a polarized plug but the NEUTRAL was switched (and fused.)

In the US North American system, something as simple as a lamp benefits from the added safety of a polarized plug (assuming the lamp is wired correctly).

What do they do in Europe? Are non-polarized and potentially neutral-switched lamps operating at 240 V. the standard?

Beachcomber

No, only in those countries with unpolarised supplies. In the UK (and probably most other EU countries with polarised supplies), that would be illegal. It is also a requirement in the UK (and likely elsewhere too) that screw fitting lampholders do not have the live/hot connected to the outer screw contact.

| Despite efforts to standardize the normal power deliver voltage at | 230V 50 Hz (at least on paper), Europe still seems to have a | collection of hopelessly incompatible power plugs and sockets as you | cross the old borders from Germany, to France, Italy, Switzerland, | etc. | | I'd be curious to know what readers (especially Euro readers) consider | to be the superior models and why? Are there any candidates for a | standard Euro power plug in the future?

I vote for the German Schuko. It can be rotated 180 degrees and still be inserted (so the cord attached to the side can go either direction). It also closes off exposure to the prongs before they make contact to the power.

| For example, I understand that the German Shuko is considered superior | because of its grounding arangements, but it lacks the ability to | preserve polarity between the hot and neutral wire. Is the right? Is | polarity less important in the Euro System when compared the the USA | North American wiring system.

The grounding is good, too. The plug can also be made compatible with the French outlet (though I hate that ground pin sticking out from it).

I think polarity should not matter. Nothing should ever be wired up so as to depend on which is grounded. It should then also work even if the system is grounded at the transformer center tap, as found in the USA. That would lower the line to ground voltage. Of course it will increase the cost of the on/off switch, since it will have to switch both wires.

Light sockets should not be the Edison screw base type. As I understand it, these are being phased out in Europe, anyway.

| If you were designing the electrical system of a country from scratch | (say a developing island somewhere), what existing plugs and sockets | would you specify? ... or would you design something new?

I'd probably stay with the Schuko for single phase up to 16 amps. Then I'd have a larger one for three phase up to 32 amps.

| Forgetting political considerations and focusing exclusively on | technical factors: | | Would you pick the Euro 230 (1 hot, 1 neutral, 1 earth conductor | scheme) or the US N.A. 120/240 Edison scheme, (2 hots, 1 neutral, 1 | ground) or some other voltage entirely? Why?

I'd want to make sure everything can work whether one of the wires is grounded, or the transformer center tap is grounded. Then I'd go with three phase power at 433/250 volts (750/433 for industral demands).

I'd also promote a low voltage standard for lights, electric razors, and other small tools. That might be 25 volts.

| 50 or 60 Hz? Why?

Maybe 75 Hz. Tesla recommended 60. 50 was chosen in Europe over 60 just to be more "metric like". I think that was a poor choice.

| In the US North American system, something as simple as a lamp | benefits from the added safety of a polarized plug (assuming the lamp | is wired correctly).

The standard Edison screw base lampholder is big enough to stick your finger in. I'd outlaw that and require a bi-pin type standard.

| What do they do in Europe? Are non-polarized and potentially | neutral-switched lamps operating at 240 V. the standard?

They have fewer dangerous screw base sockets.

Why? Just thin out the gene pool rather than continue to dilute it.

Well, the bi-pin will also permit a finger insertion. I remember seeing them in hotels some years ago. (It was on thoese trip I first saw compact flourescent lamps in small fixtures.)

The bi-pin all but requires that the lamp base have a metal shell that carries the two locking pins. The ones I saw required that bulb to be inserted with the locking pins lined up with groves and then "twisted" about

45 degrees to lock it it. I wondered at the time whether all that necessary "floating" metal (needed for mechnical strength but not used as an electrical conductor) could get accidentally energized by EITHER of the two current carrying contacts.

I wonder wherther the "baseless" bulbs used in automobiles and some flashlights are the "shape of things to come." I always associate metal with "conductor."

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