IEC plug/socket... live vs neutral?

[Benta]

Wiring a wall outlet is one thing. Manufacturing a powercord is another.  I dont see any reason to make a power cord in both straight and crossover. But apparently in europe this makes the cord safer.

No. There's no doubt that some of your power cords are wired incorrectly; for both the IEC connector as well as the wall connector that can only be plugged in one direction, there are codes.

But the most common Euro plug, which is the CEE 7/4, can be plugged in both directions. So it makes sense to design appliances without preferences as to what is live or neutral. And this increases safety.

[Benta]

I don't think he is confusing appliances and installations.

If the mains plug, is non-polarised then it makes sense to assume that either active conductor is phase.

If there's a polarised mains plug, then it's perfectly reasonable to assume that live and neutral are correctly wired up and the fuse and switch should always be on the phase side.

Unfortunately, this is a only in a dream world.

In the real world, a UK consumer* would buy a 230 V appliance from Amazon (or another online dealer) and get it delivered with a Schuko (CEE 7/4) cable, because that's how appliances are delivered these days (don't tell me it's illegal in the UK, because that's moot).
He will then go to his local electric shop and buy one of those nice cigar-box sized, 3-prong, UK-type plugs, cut off the Schuko and do the wiring of the plug himself.
Few people will have any idea of polarity, but there's always a little cardboard sign saying green/yellow must go to earth, making certain they don't kill themselves.

That's the reality. And that's why talking about live and neutral in an appliance is unhelpful. It's safer to treat them both as live.

* just an example, it applies to any 230 V country using polarized plugs, France/Belgium excepted (Schuko fits in their receptacles).

[Zero999]

I don't think he is confusing appliances and installations.

If the mains plug, is non-polarised then it makes sense to assume that either active conductor is phase.

If there's a polarised mains plug, then it's perfectly reasonable to assume that live and neutral are correctly wired up and the fuse and switch should always be on the phase side.

Unfortunately, this is a only in dream world.

In the real world, a UK consumer would buy a 230 V appliance from Amazon (or another online dealer) and get it delivered with a Schuko (CEE 7/4) cable, because that's how appliances are delivered these days (don't tell me it's illegal in the UK, because that's moot).
He will then go to his local electric shop and buy one of those nice cigar-box sized, 3-prong, UK-type plugs, cut off the Schuko and do the wiring of the plug himself.
Few people will have any idea of polarity, but there's always a little cardboard sign saying green/yellow must go to earth, making certain they don't kill themselves.

That's the reality.

The cardboard sign also shows which terminals the blue and brown should go to.

And in the case of shit from Amazon/ebay, the polarity of the live and neutral should be the least of your worries. The insulation is often crappy plastic with poor abrasion resistance and conductors copper plated aluminium and too thin for the current rating. The correct course of action is to discard the cable and buy the correct cable.

[Benta]

First, sorry, I was improving my post as you posted.

Second, I'm not talking about cr*p from Amazon, I'm talking brand products. Siemens, Bosch, Miele...

[Monkeh]

First, sorry, I was improving my post as you posted.

Second, I'm not talking about cr*p from Amazon, I'm talking brand products. Siemens, Bosch, Miele...).

That's Amazon's sourcing to get lower prices and isn't that common. How do I know? .. I live here and buy things.

[grumpydoc]

If the mains plug, is non-polarised then it makes sense to assume that either active conductor is phase.

If there's a polarised mains plug, then it's perfectly reasonable to assume that live and neutral are correctly wired up and the fuse and switch should always be on the phase side. When designing an appliance one must assume the installation is wired correctly and one can't be held liable for a shock/fire due to a faulty installation, i.e. reversed phase and earth conductor. I doubt anyone designing something with a 3 phase + neutral plug, would presume phase and neutral are interchangeable and consider switching two of the phases and the neutral.

It would seem that way but let me offer you a counter example.

If you are in France and plug in a piece of equipment which uses a Schuko to IEC lead you will almost certainly end up with live and neutral swapped in the equipment, despite the polarised plug.

The reason is that all of the Schuko to IEC leads that I have ever encountered (I suspect even those bought in France¹) are wired to the German pattern which puts the live on the left of the socket and the French put it on the right (as viewed looking into the socket as installed).

In fact the French "normes" only require the live on the right if the earth pin is at the top of the socket - if the socket has been inverted there is no convention.

Also - and, OK, I don't think this is entirely a fair criticism - if you use one of the Schuko to UK adapters in France you will find the British plug goes in upside down and live and neutral will be swapped - putting the fuse on the neutral side is not all that great for safety.

[1] I'm not sure whether any of the many Schuko  to IEC leads that I possess were bought in France, I suspect that they were all bought in the UK or that I acquired them in equipment where they were an "extra" because the box contained both a European and a UK lead. BUT all the ones that I have seen on sale in France look to be the usual Chinese imports and I doubt they do a French specific version but just ship the CEE 7/7 hybrid plug.

In the real world, a UK consumer* would buy a 230 V appliance from Amazon (or another online dealer) and get it delivered with a Schuko (CEE 7/4) cable, because that's how appliances are delivered these days (don't tell me it's illegal in the UK, because that's moot).
He will then go to his local electric shop and buy one of those nice cigar-box sized, 3-prong, UK-type plugs, cut off the Schuko and do the wiring of the plug himself.

Splitting hairs it will be delivered with a hybrid CEE 7/7 plug.

Also, unless bought via one of the European sites (amazon.fr, Amazon.de etc) it should be delivered with a IEC to BS1363 lead - in fact a lot of things that I have bought simply have both as noted above.

If not s/he probably will just go and buy a pre-made lead because most people are too lazy and too deskilled to wire a plug and the chances are a prefabricated lead costs less than a plug anyway.

[Benta]

If not s/he probably will just go and buy a pre-made lead because most people are too lazy and too deskilled to wire a plug and the chances are a prefabricated lead costs less than a plug.

Unless it's a fixed lead.

[Zero999]

If not s/he probably will just go and buy a pre-made lead because most people are too lazy and too deskilled to wire a plug and the chances are a prefabricated lead costs less than a plug.

Unless it's a fixed lead.

If it's a fixed lead, then it wouldn't be an IEC lead.

If the mains plug, is non-polarised then it makes sense to assume that either active conductor is phase.

If there's a polarised mains plug, then it's perfectly reasonable to assume that live and neutral are correctly wired up and the fuse and switch should always be on the phase side. When designing an appliance one must assume the installation is wired correctly and one can't be held liable for a shock/fire due to a faulty installation, i.e. reversed phase and earth conductor. I doubt anyone designing something with a 3 phase + neutral plug, would presume phase and neutral are interchangeable and consider switching two of the phases and the neutral.

It would seem that way but let me offer you a counter example.

If you are in France and plug in a piece of equipment which uses a Schuko to IEC lead you will almost certainly end up with live and neutral swapped in the equipment, despite the polarised plug.

The reason is that all of the Schuko to IEC leads that I have ever encountered (I suspect even those bought in France¹) are wired to the German pattern which puts the live on the left of the socket and the French put it on the right (as viewed looking into the socket as installed).

In fact the French "normes" only require the live on the right if the earth pin is at the top of the socket - if the socket has been inverted there is no convention.

Also - and, OK, I don't think this is entirely a fair criticism - if you use one of the Schuko to UK adapters in France you will find the British plug goes in upside down and live and neutral will be swapped - putting the fuse on the neutral side is not all that great for safety.

[1] I'm not sure whether any of the many Schuko  to IEC leads that I possess were bought in France, I suspect that they were all bought in the UK or that I acquired them in equipment where they were an "extra" because the box contained both a European and a UK lead. BUT all the ones that I have seen on sale in France look to be the usual Chinese imports and I doubt they do a French specific version but just ship the CEE 7/7 hybrid plug.

If something is designed to be safe and work properly in one location, one shouldn't expect it to do so elsewhere. Fine for appliances designed to work across Europe, then I concede that it's good practise to design for non-polarised, single phase mains, otherwise it's silly. For example, I use US appliances here in the UK, via a transformer. The line frequency is 50Hz, rather than 60Hz, which isn't good for the transformers. I accept that there's a risk of overheating and I'm probably voiding any warranties by operating the equipment outside its specification.

[Benta]

'nuff said. Good night 

[grumpydoc]

If something is designed to be safe and work properly in one location, one shouldn't expect it to do so elsewhere. Fine for appliances designed to work across Europe, then I concede that it's good practise to design for non-polarised, single phase mains, otherwise it's silly. For example, I use US appliances here in the UK, via a transformer. The line frequency is 50Hz, rather than 60Hz, which isn't good for the transformers. I accept that there's a risk of overheating and I'm probably voiding any warranties by operating the equipment outside its specification.

I did say that catering for the Schuck to BS1363 adapters was probably a bit much to ask manufacturers.

But the fact remains that despite polarised plugs there are still enough differences across Europe that you can't rely on which side is live when selling into that market - once you have designed around that for Europe there isn't any point in providing a variant for markets where you can guarantee which side is live (assuming a correct installation and correctly wired plug).

[tronde]

I found some interesting reading from Schneider Electric about earth systems.

https://www.eevblog.com/forum/beginners/electronics-primers-course-material-and-books/msg1273697/#msg1273697