Electrical plugs (Split from National Postcodes to be introduced)

Impetus · 22-05-2014 9:13pm

Sam Russell wrote: »

@Impetus

You might find this a starting point.

http://www.etci.ie/docs/certguide112009.pdf

Standards are not just for you, but those that follow you. You could wire according to French or some other standards, but electricians coming to repair, extend, or service the installation at a later date may be put in danger if they do not recognise or understand the installation. It may be possible to use a version of the Irish code that matches the French system. For example use only spurs, not ring-mains, with a single circuit-breaker per plug. There could be requirements that cannot be matched.

However, you are now required to use certified electricians, as you are required to use certified gas installers for gas.

In my view that is just bad bureaucracy. Corrupt. See you in court time, and see if you can defend your crappy standards?

Albania, Austria, Bosnia and Herzegovina, Bulgaria, Chile, Croatia, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Indonesia, Iran, Italy, Latvia, Lithuania, Luxembourg, Republic of Macedonia, Republic of Moldova, the Netherlands, Norway, Pakistan, Portugal, Romania, Russia, Serbia, Slovenia, South Korea, Spain, Sweden, Turkey, Ukraine, and Uruguay can't be all wrong.

Or perhaps they are all out of step except for my Seány? (and Nigel!)

Impetus · 22-05-2014 9:15pm

If nothing else Ireland's 3 pin sockets are a restraint of trade - forcing appliance makers to create a separate product for the British Isles lot. It increases cost, reduces choice and makes one less mobile - without the crutch of an adapter or two.

Sam Russell · 22-05-2014 10:52pm

I am not defending the UK plug system. Nor am I involved in the electrical supply nor am I an electrician.

However, standards exist for a reason other than burocracy. Most of the countries you list plus most of the others in the world drive on the right hand side of the road. I suggest that you do not do so here just because you think that they cannot all be wrong!

Plug design was partly restrictions on trade and partly because they were develped independantly of each other. The same happened with the developement of chocolate, and each country makes a different version of chocolate. The exact way a chocolate bar was produced from cocoa was a secret closely guarded and each manufacturer had to work it out for themselves. Unfortunately for us, the Belgians and the Swiss produced a better product than we have ended up with.

The American's choice of 60Hz give them more efficient transformers and motors. Their choice of 110V was unfortunate if you want to boil water in a kettle. By the way Europeans do not tend to use electric kettles, but then they do not drink tea.

The Europeans consider the fused plug as dangerous (and I agree with them). The UK consider the absence of a fuse in the plug as dangerous.

You cannot win.

22-05-2014 11:08pm

Sam Russell wrote: »

The UK consider the absence of a fuse in the plug as dangerous.

Pointless perhaps but not dangerous if the building wiring is of a modern standard.

To be honest a fused plug is a hangover from when there was probably only one socket in the room and a trailing cable to the appliance or extension lead with half a dozen adaptors with a load of kit hanging off of it (more common than you think back in the 1960s).

That cable would often be squashed under furniture or trodden on as well, the risk of a short circuit were real.
The fuse was really needed to prevent the cable from burning out before the main fuse went after it shorted out.

Carawaystick · 23-05-2014 1:16am

Impetus wrote: »

,Bosnia and Herzegovina, Croatia, Estonia, Germany, Iceland, Latvia, Lithuania, Republic of Macedonia, Republic of Moldova, Russia, Serbia, Slovenia, Ukraine,

None of these countries existed when I was growing up in the 80s, so they're hardly a sign that our system is wrong.
Even in France there are 2 types of plug, close fitting earthed ones and loose 2 pin ones.
Also in France, many old homes are wired with circuit breakers, not rcbo,

Sam Russell · 23-05-2014 8:52am

Deleted User wrote: »

Pointless perhaps but not dangerous if the building wiring is of a modern standard.

To be honest a fused plug is a hangover from when there was probably only one socket in the room and a trailing cable to the appliance or extension lead with half a dozen adaptors with a load of kit hanging off of it (more common than you think back in the 1960s).

That cable would often be squashed under furniture or trodden on as well, the risk of a short circuit were real.
The fuse was really needed to prevent the cable from burning out before the main fuse went after it shorted out.

The reason for the fuse in the plug is nothing to do with the scene shown above.

The fused plug arises because of the 'inovation'of the ring main. It was designed that a 32 amp feed would loop araound a part of a premises, say a floor, where all sockets would be fed fron the loop which would return to the main fuse. Thus any plug would draw current from both directions of the loop. Instead of having one 15A fuse per feed, a 32 A fuse fed the ring main and each outlet carried the appropriate fuse for the appliance - 13A, 10A, 5A, 3A. The old system required each plug to be fed by a single line and fused with a 15A or 5A fuse. The plugs were different for each type. (The 5A is still used for switched light circuits).

It all sounded fine, but the use of circuit-breakers allowed the old system to be improved but the fused plug could not fit a CB. Fuses by their nature heat up as they approach the design limit (because that is how they work). 13A is enough to cause a fire in a faulty plug. The intoduction of Earth Leakage and the like improved safety, but the fuse remains. Fuses are there to protect the wiring and prevent electrical fires.

The fuse could be incorporated in the device, but overloading is still a problem.

L1011 · 23-05-2014 10:05am

Impetus wrote: »

If nothing else Ireland's 3 pin sockets are a restraint of trade - forcing appliance makers to create a separate product for the British Isles lot. It increases cost, reduces choice and makes one less mobile - without the crutch of an adapter or two.

You are aware surely that the vast majority of appliances have had separate leads for decades at this stage? Meaning zero change in the appliance, only one cheap lead.

Its fairly standard for the same SKU of a computing product to come with three or more power cables (BS, Schuko and US) and maybe a sack of phone leads if it has any telephony functions.

As it stands the need for different keyboards for every country in Europe more or less is a far bigger issue for computer vendors than plugs ever could be.

murphaph · 23-05-2014 11:34am

Impetus wrote: »

I agree North American plugs are rubbish too. I don't know why they don't standardise on the European plug over there.

$$$. Same reason everywhere. Switching such legacy systems over involve hassle and expense, so these systems remain.

Impetus wrote: »

You don't need a shutter in a socket where the hole is relatively small

Lol, tell that to my inquisitive son who likes poking things into other things. In our flat (in Berlin, rewired about 20 years ago) the sockets don't appear to be on the RCD, just on MCBs. How do I know? I managed to conduct across my fingers when I "found" an old socket that had no cover (some idiot wallpapered over it). Nothing tripped. If my son stuck something metallic into the old sockets (no shutter) it could kill him. That was a design advantage of the 3 pin socket, but as I say, new sockets here can be found with the shutter, though they aren't mandatory (probably because RCDs are now).

I agree with your broad point that the ring mains and its fused plug is a poorer system over star designs with lightweight plugs/cords and suitable MCBs on each spur...you can probably wire your place in a star configuration but you will not be able to put Schuko sockets in it and to be honest I think you'd be mad to. Every single device you buy in Ireland will need to have its plug changed and visitors to your house won't be able to use anything they've brought with them without an adapter...it's just weird.

Sam Russell · 23-05-2014 1:06pm

murphaph wrote: »

I agree with your broad point that the ring mains and its fused plug is a poorer system over star designs with lightweight plugs/cords and suitable MCBs on each spur...you can probably wire your place in a star configuration but you will not be able to put Schuko sockets in it and to be honest I think you'd be mad to. Every single device you buy in Ireland will need to have its plug changed and visitors to your house won't be able to use anything they've brought with them without an adapter...it's just weird.

Each system was designed to overcome different problems and should be used in total.

In my Kitchen, I have a worksurface that has 3 double sockets and one single socket on the floor, all of which is served within a single ring-main fused (CB) to 32 amp. On that circuit is a kettle (13A), a toaster (5A), a coffee m/c (5A) and occasional use of a few other appliances, with the floor socket feeding a fridge/freezer (3A). If all are on load together, that makes 26A. If a hair dryer (10A) was also on, the consumption could be 36A. Now the ring main design allows diversity - that is it allows an assumption of occasional use to allow the overall load to be exceeded. In the spur design, this is not allowed. Because each socket in the UK can draw 13A, it is upto the plug to limit the draw to 5A, 10A or 13A. It would make sense if the plugs were shaped or coloured to display the internal fuse value, and perhaps made so a different fuse could not be used.

Once you go with a system, yoy need to use all of it.

The French system relies on ''double insulation''' which means that there are two systems of insulation on the neutral and live, minimising the danger of shock, obviating the need for an earth connection.

The German system plugs and fuses were used in Ireland up to the 60s as we used the whole German system from the founding of the ESB.

Impetus · 23-05-2014 1:18pm

murphaph wrote: »

$$$. Same reason everywhere. Switching such legacy systems over involve hassle and expense, so these systems remain.

You don't have to get everybody to re-wire their house overnight. New houses and commercial buildings could be fitted with Schuko sockets, and have them gradually introduced as premises are re-wired.

Sweden moved from driving on the left to driving on the right hand side in the 1960s. They started off with very low speed limits in the first week or so while people got used to it, and succeeded in the change-over without any problems.

murphaph wrote: »

Lol, tell that to my inquisitive son who likes poking things into other things. In our flat (in Berlin, rewired about 20 years ago) the sockets don't appear to be on the RCD, just on MCBs. How do I know? I managed to conduct across my fingers when I "found" an old socket that had no cover (some idiot wallpapered over it). Nothing tripped. If my son stuck something metallic into the old sockets (no shutter) it could kill him. That was a design advantage of the 3 pin socket, but as I say, new sockets here can be found with the shutter, though they aren't mandatory (probably because RCDs are now).

Older British plugs didn't have insulation on the backs of the pins, and people suffered electrocution as a result of part of their hand touching a pin while it was being inserted in the socket. You can't do that with the continental system because the socket entry is not flush - you plug into the socket.

BT invented its own incompatible (non RJ11) phone socket, which had a big hole for little fingers to get electrocuted if an incoming call arrived at the time causing the ringing current to be sent down the line.

murphaph · 23-05-2014 4:30pm

French sockets provide an earth. They don't rely solely on double insulation. The french earth is a prong in the socket. The German earth is built into the top and bottom of the socket. An earthed german plug can't be inserted into a French socket. That's one of the reasons the Europlug was invented for non earthed devices.

Impetus · 23-05-2014 4:54pm

murphaph wrote: »

French sockets provide an earth. They don't rely solely on double insulation. The french earth is a prong in the socket. The German earth is built into the top and bottom of the socket. An earthed german plug can't be inserted into a French socket. That's one of the reasons the Europlug was invented for non earthed devices.

My French plugs have both a hole for the earth prong in the French socket and side earth contacts to earth the appliances in German sockets. Universal. I have German purchased appliances too and they have an earth connector for the French earth prong.

MBSnr · 26-05-2014 11:28am

Impetus wrote: »

We are big into anti-British rant claims in this territory. I did say in the other thread that I was trying to think of an area where the British excel. It came to me the other day - "appearances". Royal family pageantry and similar. They do it like no other country.

The only problem is that these appearances can be used to pull the wool over peoples' eyes.
Just because one can put on a world class display involving some royals accompanied with their army trooping down some boulevard does not mean that you are a good engineer. Unfortunately in Britain most intelligent engineers are working in financial jobs in London - instead of less lucrative jobs like electrical engineering, mechanical engineering etc. GB has paid a big price as a result, and Ireland is paying the price whenever it copies second rate solutions devised by second class minds who have been programmed to do everything possible to be different (which often means anti-European) for the sake of it.
.
.

So you have anti-British rant predisposition and then find an area they excel in, which you then ironically turn it back into just another of your anti-British posts... Good work.

So most UK intelligent engineers work in financial jobs in London? Is that a published fact then? The UK leads the way in many high tech engineering fields including Formula 1.

Fancy having a go at the French (for once

)? They have ordered these trains that are too wide for the stations and the cost is reported to be €50m to fix... Or perhaps all their intelligent engineers work in the London financial sector as well?

Sam Russell · 26-05-2014 11:52am

Maybe we should have a go at the lamp design. ES (Edisson Screw) or baynet? Not to mention GU10, G9, etc.

Oh dear, when God designed standards, he designed plenty of them.

26-05-2014 6:33pm

Sam Russell wrote: »

Maybe we should have a go at the lamp design. ES (Edisson Screw) or baynet? Not to mention GU10, G9, etc.

Oh dear, when God designed standards, he designed plenty of them.

What, to bring forward the day of reckoning you mean.

SpaceTime · 26-05-2014 6:37pm

Ireland used Schuko (German style earthed plugs) at one stage along side the older round-pin UK ones.

The bigger issue for us at the moment is that if we changed to continental plugs, because most distributors see us as an adjunct to the UK market, we would end up with appliances with plugs that don't fit our sockets.

Note how many telephones, modems etc come with BT plugs even though the Irish RJ11 plug is the most common and standardised connector in the world. The distributors just don't give a damn and see us as Western Manachester or something.

The modern continental plug system is called CEE 7.
It's used everywhere except Italy, Switzerland and Denmark and is now used right across the former USSR and in many other countries including South Korea. It's probably the most commonly used system in the world.

Basically you've three plugs :

CEE 7/7 - 16 amp earthed.
CEE 7/17 - 16 amp unearthed (for stuff like vacuum cleaners, hairdryers etc)
CEE 7/16 - 2.5amp unearned flat plug (small appliances only)

All of these plugs are designed to fit two types of sockets : CEE 7/4 (German style with grounding clips) and CEE 7/5 (French style with grounding pin).

Both sockets are recessed so you cannot touch the pins of the plugs when you're inserting/removing them and many countries (particularly France) also have shuttered sockets as mandatory.

The sockets are usually on 16amp radial circuits (although sometimes 20amp too).

All in all, it's a very safe system - the only issues you'll find is where older non-earthed sockets are still in use.

You've a few odd-ball systems then too which use the same 2 round pin system, but have their own way of earthing things.
Italy, Switzerland and Denmark.

UK, Ireland, Cyprus and Malta all use the same system which is deliberately designed to be incompatible due to ring circuits needing fused plugs.

SpaceTime · 26-05-2014 6:51pm

Sam Russell wrote: »

@Impetus

You might find this a starting point.

http://www.etci.ie/docs/certguide112009.pdf

Standards are not just for you, but those that follow you. You could wire according to French or some other standards, but electricians coming to repair, extend, or service the installation at a later date may be put in danger if they do not recognise or understand the installation. It may be possible to use a version of the Irish code that matches the French system. For example use only spurs, not ring-mains, with a single circuit-breaker per plug. There could be requirements that cannot be matched.

However, you are now required to use certified electricians, as you are required to use certified gas installers for gas.

It doesn't mean a single circuit breaker per plug either. Ireland normally uses radial circuits too (very commonly). You can have quite a few sockets per circuit.

That's your typical modern French setup : http://leniddecastors.free.fr/wp-content/uploads/Tableau-electrique.jpg

Split panel with multiple RCDs and they'll allow up to 8 sockets per radial.

Incidentally, the European Commission and CENELEC worked on a proposed 16amp, recessed, very neat plug (largely based on the Swiss system but with higher load and safer). However, the UK vetoed its use and it was abandoned.

It's now IEC 60906-1 and is used by Brazil and also being adopted by South Africa.

http://en.wikipedia.org/wiki/IEC_60906-1

Would have been a far neater job than any existing European system.

The CEE 7 system was considered too well established and a de facto pan-EU standard anyway so, that was also another big deciding factor. Changing it would be extremely expensive as there are hundreds of million sod appliances and sockets.

The primary concern seems to be to ensure that people are using MODERN versions of CEE 7, not old pre WWII unearthed sockets.

CatInABox · 27-05-2014 8:17am

Sam Russell wrote: »

Maybe we should have a go at the lamp design. ES (Edisson Screw) or baynet? Not to mention GU10, G9, etc.

Oh dear, when God designed standards, he designed plenty of them.

Sam Russell · 27-05-2014 10:14am

CatInABox wrote: »

Exactly.

The differing opinions with plugs boils down to:

UK: We need a fuse in the plug to protect the wires.
EU: Fuses are a fire hazard in the plug.

UK: We need square pins for better contact and cheaper production cost.
Eu: We need round pins for better contact and higher quality production.

UK: We need a socket with a low profile.
EU: We need a socket that protects the live from fingers.

UK: We need a side entry cord so it cannot be pulled out of the socket.
EU: We need an end entry cord so it pulls out of the socket.

Etc. Etc. Etc. Etc.

I like the Swiss system, and therefore I like the proposed design, IEC 60906-1, which appears to be well thought out.

To use the continental design, the CB at the fuse box just needs to be downgraded to 16A from 32A and high demand items like electric heaters and the like be retired. This would work for most installations. Obviously plugs and sockets would need to be changed.

SpaceTime · 27-05-2014 10:25am

Sam Russell wrote: »

To use the continental design, the CB at the fuse box just needs to be downgraded to 16A from 32A and high demand items like electric heaters and the like be retired. This would work for most installations. Obviously plugs and sockets would need to be changed.

Most Irish installations actually use 16A and 20A radials anyway. I've never encountered rings in any property I've lived in here (although they are used).
So, a very large % of Irish homes basically use continental style wiring with British style sockets anyway.

Have a look at your own fusebox sometime. You'll be unlikely to find many 32Amp circuits other than the cooker or shower circuits and probably have a large number of 20A or 16A circuits instead.

There would be no reason to retire heaters either. Continental outlets can safely deliver over 3600W where as our fused plugs can only carry 2990W safely.

The usual setup in continental Europe is a 20A circuit serving 8 sockets and it seems to work 100% fine. Cords don't burst into flames!

The way the European sockets are recessed to prevent your fingers touching the pins makes more sense than the way the UK ones do it. British plugs originally had no sleeves on the pins. So, to minimise the risk of touching the pin, the plug only makes contact at the very tip of the pin when it's almost fully inserted. This means that the plug doesn't really have that much surface area in contact with the socket. The result of that is that if the plug is overloaded or if the springs are a little loose on the socket, the pins get very hot. The continental ones don't have sleeved pins on 16A plugs as the design doesn't need them to protect your fingers and the socket makes contact with much more of the pin.

You also have a risk of the fuse not being quite in position in the plug. The holders are often pretty flimsy arrangements. If the fuse is loose and the plug is carrying its maximum load (e.g. a heater) there's a serious risk it will run very hot.

The Swiss system is OK, to a point. The old sockets weren't recessed and were pretty dangerous as it was almost difficult to avoid touching the pins! The new ones are very safe though.
Also, it was 10 amps instead of 16amps, which is a bit silly as it limits your appliances to very low wattages.

The UK 13amp system is also way out of line with the continental 16amp approach. So, you end up with special versions of appliances for UK/IRL e.g. tumble dryers, microwaves etc that have to be limited to about 2880W
Sometimes, they just use the lowest common denominator and limit the entire European production to 2880W to suit the UK so they don't have to make a 2nd version.

In a lot of cases these days it's done with software, so a UK version of a dryer for example will just never switch on the full load of heaters. Where as if it's programmed for EU mode it will.

...

That being said, both the UK and continental systems are reasonably safe when used correctly and when you're talking about modern installations.

...

If you were going to change to the IEC pan-European standard smaller, neater plug. You'd end up with 30+ years of adaptors! People aren't going to just replace their sockets until they have to rewire their house / redecorate and then how would they use their old appliances? You'd have a mess of adaptors for years like the way we used have in the 60s!

SpaceTime · 27-05-2014 11:59am

You can see why the South Africans adopted the IEC plugs though! They originally used the enormous old round pin British ones :

http://mybroadband.co.za/vb/attachment.php?attachmentid=98309&d=1391684384

Sam Russell · 27-05-2014 12:01pm

I checked my consumer unit.

There is a big fat ES German-type fuse for the incoming current.
A 110 A CB as the main CB.

A 32A CB for the cooker
Lights 10 A BY FOUR
I have two ELCBs
On the first 20 A by two
on the second 32A by one
20A by five.

So only one ring main fully exploited. Seven ring mains at 20 A.

Two ELCBs are to seperate areas of the house to prevent the whole house losing power at once.

I could probable reduce the 32 A ring main to 20 A if I wanted to as there is no major appliance on it. Reducing the 20 A ones to 16 might be a bit excessive. The 32 A one for the cooker is amost certainly a spur.

A way of converting the BS1363 to the IEC 60906-1 could be accomplished by incorporating both into the socket design as a transition. It would fit and would be safe if the fuse lark could be solved. I will not hold my breath.

SpaceTime · 27-05-2014 12:03pm

Sam Russell wrote: »

I checked my consumer unit.

There is a big fat ES German-type fuse for the incoming current.
A 110 A CB as the main CB.

A 32A CB for the cooker
Lights 10 A BY FOUR
I have two ELCBs
On the first 20 A by two
on the second 32A by one
20A by five.

So only one ring main fully exploited. Seven ring mains at 20 A.

Two ELCBs are to seperate areas of the house to prevent the whole house losing power at once.

I could probable reduce the 32 A ring main to 20 A if I wanted to as there is no major appliance on it. Reducing the 20 A ones to 16 might be a bit excessive. The 32 A one for the cooker is amost certainly a spur.

A way of converting the BS1363 to the IEC 60906-1 could be accomplished by incorporating both into the socket design as a transition. It would fit and would be safe if the fuse lark could be solved. I will not hold my breath.

They're most likely 20 amp radials, not ring mains.

Rings would typically be a 32amp breaker feeding sockets. The wiring runs around in a ring and is connected to the circuit breaker at both ends i.e. a ring.

The 20A circuits are most likely just a radials - in Ireland they would typically allow 10 sockets per radial so they're not exactly restrictive and a double-socket is treated as a 'socket'.

In France, they're a little more conservative and give you 8 sockets per radial (but the sockets can deliver much more power being 16Amp)

If your 2nd 32 amp MCB is feeding sockets it's almost definitely a ring.
It could also be for your electric shower or some other heavy fixed appliance.

---

You could definitely produce a combined French or Schuko socket that would also accept the 3-pin IEC 60906-1 plug. Basically all that's required is an extra earth 'hole' in the face of the socket and it would fit perfectly. The Live and Neutral pins are basically the same as existing Schuko plugs.

You could begin to phase out the old plugs then.

With the BS1363 system we use, producing a hybrid wouldn't be as easy. You would probably just have to put both sockets on the same plate. Although it would be handy as you could ultimately put 4 sockets on what we have as a double socket now. Would be very handy in the kitchen or behind the telly.

I suppose the simplest solution would be a 16A fuse or breaker in the socket, making them compatible with 32amp rings.

Sam Russell · 27-05-2014 12:11pm

I am fairly sure they are rings but not entirely sure as it is nearly 30 years when the house was rewired. Some work has been done since, but it was all done to a very high standard plenty of sockets, etc.

The ELCB s are all for sockets. The second was was to seperate computers from the main house. Would not want the computer to die because someone spilled water on the toaster, would I.

SpaceTime · 27-05-2014 12:32pm

It seems 20 amp rings were allowed at one stage, but that's no longer the case and hasn't been for some time.

Radials would be 16 or 20A
Rings 32A

(In modern regs anyway.)

For all intents and purposes, a 20 amp circuit (radial or otherwise) is still a 20amp circuit though. So, the setup in terms of protection would be very similar to a continental radial really other than that you're using British style plugs.

I know in this house, the wiring is 20A radials to junction boxes which then seem to feed out to the sockets in a kind of root and branch sort of layout.
It would have been wired in 1977/78.

Each one seems to serve 1 large room or 2 smaller rooms max and there are 3 serving sockets in the kitchen.

Sam Russell · 27-05-2014 2:15pm

I am reasonably certain these are rings. The fuse value can be set lower without any risk. The benefit of a ring is the increase in diversity that it gives. It has two routes for the current to go, so effectively it is twice that of a spur system, and it gives greater flexibility with cable routing.

The fused plug is a mistake, and does not improve safety in any real way and can be a source of fire (as I have witnessed). The fuse is another failure point and is not needed if ELCBs or RCDs are used intelligently as they are under current regs (parden the pun).

It is ridiculous to require a fused plug to protect the cord, as is the reason given for the fuse.

If the fuse is dropped from the design, it is not a great difference between the two designs.

SpaceTime · 27-05-2014 2:22pm

My only concern about 20 amp rings would be if they allowed people to derate the wiring like they do with 32A rings.

The theory is that you can feed a 2.5mm2 cable from both ends and increase its current carrying capacity as the electricity is in theory flowing two directions.

The whole point of rings was to allow thinner wiring, thus saving copper rather than to improve diversity.

I'd hope that 20A radials aren't running on 1.5mm2 cable or something!

The main flaw with rings is that if the ring is broken, you end up with 32A fusing on a circuit only capable of carrying 16A.

You've also got a problem if most of the load is at one end of the ring, as it will be unbalanced and in theory (especially if the other side is very long) you could have an overloaded half of the ring where most of the power is being drawn along the short side.

This is the main reason they're no longer allowed in kitchens - big loads all clustered.

At this stage the best option for standardising, if we were going that route would be for Ireland to adopt French sockets. They're shuttered and polarised (plug only goes in one way) and are 100% compatible with modern CEE 7 plugs.

Sam Russell · 27-05-2014 3:49pm

SpaceTime wrote: »

My only concern about 20 amp rings would be if they allowed people to derate the wiring like they do with 32A rings.

The theory is that you can feed a 2.5mm2 cable from both ends and increase its current carrying capacity as the electricity is in theory flowing two directions.

The whole point of rings was to allow thinner wiring, thus saving copper rather than to improve diversity.

I'd hope that 20A radials aren't running on 1.5mm2 cable or something!

The main flaw with rings is that if the ring is broken, you end up with 32A fusing on a circuit only capable of carrying 16A.

You've also got a problem if most of the load is at one end of the ring, as it will be unbalanced and in theory (especially if the other side is very long) you could have an overloaded half of the ring where most of the power is being drawn along the short side.

This is the main reason they're no longer allowed in kitchens - big loads all clustered.

Using thinner wire is the same as increased diversity. If every socket took the max - or even close, the CB cuts the current.

All our plug wires are the same thickness IIRC, so I doubt the wires are derated.

The ring is designed to cope with all the load at one end. Half the current comes from the left and half from the right. Always.

If the ring is broken, yes you have a problem - particularly if you do not know it is broken. Probably a fire as well, but thev ELCB should cut the current if there is a short to earth.

SpaceTime · 27-05-2014 3:55pm

That's actually not the case and has been demonstrated not to be.

If the ring is very large (common in Ireland in bungalow type homes) you can have a very long leg and a very short leg relative to the position of the load.

If you've say 30amps load sitting close to the circuit board on one side and may metres away on the other side, the shorter leg can become overheated.

Allowing the use of thinner wiring is the issue. If you'd a 2.5mm2 ring rated at 20amps this wouldn't be an issue. It might be useful in overcoming voltage drops through diversity. It's where 2.5mm is allowed to be used with 32A that you can run into possible issues where it's broken or very unbalanced.

That's the reason why multiple radials were introduced for kitchens and utilities in the new regs.

You've also got a weird reg that allows ANY number of sockets in 100m2 area. That makes no sense as you need to plan for load.

Rings and very high ampage bus circuits with fused sockets were used in France in the 1950s for similar reasons but they're long, long since obsolete and banned.

The old French system even had fused light switches so lights and sockets could share wiring.

The French reason for banning them was people bypassing fuses and causing fires.

Very few counties adopted that approach to wiring.

Here's what happens (very old badly installed DIY job socket with fuse bypassed)

http://i79.servimg.com/u/f79/11/49/44/96/imgp0411.jpg

Sam Russell · 27-05-2014 4:08pm

You would need a very long ring to produce the problems you cite.

Electrical plugs (Split from National Postcodes to be introduced)

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