New design of mains plug?

[DrDaveParticipant @drdave]

Posted by herbert punter on 30/03/2020 18:10:53:

Posted by DrDave on 30/03/2020 18:01:29:

I have never understood the British love of fused plugs: most of the world seems to be happy with unfused plugs. None of the electrical equipment that I bought when I lived in Switzerland has a fused plug, for example.

Other than the regulatory requirement here (and after all it does sound like a good idea), can anyone explain why Britain and the colonies have this different plug philosophy?

It’s because we tried to save copper after the war by using ring circuits for sockets. Other countries use radial circuits with the fuse in the consumer unit rather than the plug.

Bert

Thanks for the explanation, Bert. I suspected that it might be something along those lines.

Dave

[Howard LewisParticipant @howardlewis46836]

By the sound of the comments, a powder fire extinguisher would be preferable to a box of matches. Or are they so that you find your way in the dark to the fusebox?

Howard

[SillyOldDufferModerator @sillyoldduffer]

Posted by Bill Chugg on 30/03/2020 18:02:17:

Posted by vintage engineer on 30/03/2020 17:58:46:

Doesn't CE stand for China Export?

…

Chaps seem determined to believe there's a Chinese organisation responsible for official 'China Export' or 'China Engineered' marks that are carefully designed to look like EU CE marks. Can anyone find this organisation? The EU couldn't.

Truth is fake CE marks are just fake CE marks. The initials don't stand for anything, they're an empty con. Fake plugs are sold marked 'BS1363'. No-one believes BS stands for 'Beijing Special', 'Best Stuff' or 'Bull S**t''. It's just a fake. Same problem with any other safety mark – they can all be copied by the ill-disposed.

Fraudster do what is needed to gain credibility. It is true the Chinese government don't care much about guys exporting junk, but – in the UK – it's the importer who is responsible for the validity of CE marks, not the manufacturer. Very few governments police the quality of exports, remember time-expired Baby Food sold in the third world, and clapped out racehorses in British Ready Meals.

Caveat Emptor!

Dave

[Brian Sweeting 2Participant @briansweeting2]

Posted by DrDave on 30/03/2020 18:01:29:

I have never understood the British love of fused plugs: most of the world seems to be happy with unfused plugs. None of the electrical equipment that I bought when I lived in Switzerland has a fused plug, for example.

Other than the regulatory requirement here (and after all it does sound like a good idea), can anyone explain why Britain and the colonies have this different plug philosophy?

I would have rephrase that question to why doesn't everyone else bring their electrical standards up to our UK level but I am biased of course.

[Former MemberParticipant @formermember19781]

[This posting has been removed]

[SillyOldDufferModerator @sillyoldduffer]

Posted by DrDave on 30/03/2020 18:34:15:

Posted by herbert punter on 30/03/2020 18:10:53:

Posted by DrDave on 30/03/2020 18:01:29:

I have never understood the British love of fused plugs: most of the world seems to be happy with unfused plugs. None of the electrical equipment that I bought when I lived in Switzerland has a fused plug, for example.

Other than the regulatory requirement here (and after all it does sound like a good idea), can anyone explain why Britain and the colonies have this different plug philosophy?

It’s because we tried to save copper after the war by using ring circuits for sockets. Other countries use radial circuits with the fuse in the consumer unit rather than the plug.

Bert

Thanks for the explanation, Bert. I suspected that it might be something along those lines.

Dave

More to it than simply saving copper, though that's true. The system is electrically more flexible than spurs, and though not ideal for everything, it's generally a 'good thing', well thought out. One advantage is 13A at 230V is plenty powerful enough for most domestic purposes and nearly 6kW can be pulled from a double socket by two appliances; brilliant in kitchens and workshops. A disadvantage is the plugs are massively overrated for ordinary electronics and table lamps etc. The extension leads behind British home entertainment systems could be smaller and much neater, but who cares?

The system allows spurs as well: my cooker is 40A, and the electric shower 30A. Tese are hardwired for safety and there's a special low amp spur socket for electric razors.

Dave

[Neil WyattModerator @neilwyatt]

Posted by Ian P on 30/03/2020 15:45:38:

Its not possible to visually check separation of the transformer.

Ian P

If it's an SMPSU, which I'm sure it is, it should have side by side coils.

The key thing is how well the two sides are separated on the PCB.

Neil

[Neil WyattModerator @neilwyatt]

Posted by SillyOldDuffer on 30/03/2020 18:39:32:

It is true the Chinese government don't care much about guys exporting junk, but – in the UK – it's the importer who is responsible for the validity of CE marks, not the manufacturer.

People often forget that when they buy things of Bangood ewtc. THEY are personally the importer.

Unlikely to be an issue, unless their dodgy PSU burns the house down along with theneighbours…

Neil

[Former MemberParticipant @formermember19781]

[This posting has been removed]

[not done it yetParticipant @notdoneityet]

Posted by Bazyle on 30/03/2020 17:43:36:

It isn't the plug that is a threat unless you expect it to b used by children or halfwits and you could easily clue on a plastic disc with 3 holes in it if you are really worried. The danger as mentioned above will be fire especially as it is advertised as 70W . It is switched mode so no transformer and probably fully potted inside which actually helps heat dissipation. Of course there are lots of non CE items being imported as long as you allow advertising and direct shipping of electrical goods. What do you expect – trading standards to open every package arriving from China?

What makes you believe it is ‘switched mode’? Don’t be another fooled by the advertising wording. ‘Switched’ far more likely refers to the output switch on that pot. Nowhere have I seen that it is described as a switched mode item. Please enlighten me if I am not correct.

[not done it yetParticipant @notdoneityet]

Posted by herbert punter on 30/03/2020 18:10:53:

Posted by DrDave on 30/03/2020 18:01:29:

I have never understood the British love of fused plugs: most of the world seems to be happy with unfused plugs.

It’s because we tried to save copper after the war by using ring circuits for sockets. Other countries use radial circuits with the fuse in the consumer unit rather than the plug.

Bert

Quite right, too. Who really wants a 15A fuse, at the distribution panel, to protect a flimsy 3A lead from plug to equipment? I fit an appropriate fuse for the device being used. Most certainly not a 13A fuse for most things.

Question: Are all flexible leads rated at 15A in the rest of Europe? If so, that is a waste of copper!

[old martParticipant @oldmart]

One good reason for a fuse in the plug if selected properly, (1, 2, 3, 5 ,7, 10, or 13A), is the protection it can afford each individual item. A radial will have a fuse rating for the wiring, not the components connected. A radial in the UK will have a 16A circuit breaker at the consumer unit, not great protection for anything consuming less than 3KW. 

That particular power supply was not bought with the intention of leaving it unatended. I am one of those people who disconnect the power supply from pc's after shutting them down.

 

Edited By old mart on 30/03/2020 19:52:03

[Michael GilliganParticipant @michaelgilligan61133]

Posted by not done it yet on 30/03/2020 19:32:09:

What makes you believe it is ‘switched mode’? Don’t be another fooled by the advertising wording. ‘Switched’ far more likely refers to the output switch on that pot. Nowhere have I seen that it is described as a switched mode item. Please enlighten me if I am not correct.

.

With that power output and that size … How could it not be

MichaelG.

.

Here’s a Youtube video for you: **LINK**

[DrDaveParticipant @drdave]

Posted by not done it yet on 30/03/2020 19:41:21:

Posted by herbert punter on 30/03/2020 18:10:53:

Posted by DrDave on 30/03/2020 18:01:29:

I have never understood the British love of fused plugs: most of the world seems to be happy with unfused plugs.

It’s because we tried to save copper after the war by using ring circuits for sockets. Other countries use radial circuits with the fuse in the consumer unit rather than the plug.

Bert

Quite right, too. Who really wants a 15A fuse, at the distribution panel, to protect a flimsy 3A lead from plug to equipment? I fit an appropriate fuse for the device being used. Most certainly not a 13A fuse for most things.

Question: Are all flexible leads rated at 15A in the rest of Europe? If so, that is a waste of copper!

I’ve just checked one of my Swiss socket strips: it says that it is rated at 10A max.

[Ian PParticipant @ianp]

Posted by Neil Wyatt on 30/03/2020 19:11:47:

Posted by Ian P on 30/03/2020 15:45:38:

Its not possible to visually check separation of the transformer.

Ian P

If it's an SMPSU, which I'm sure it is, it should have side by side coils.

The key thing is how well the two sides are separated on the PCB.

Neil

I am not a designer of power supplies but have seen hundreds of different designs of SMPS in everything from phone chargers to large bench PSUs and dont recall seeing more than a couple withe primary and secondary windings on separate bobbins.

Some that 'bigclive.com' has investigated and dismantled have the primary and secondary windings on alternate layers so more or less interleaved. If manufactured properly the isolation between input and output will meet or exceed the regulations, problem may arise if some other protection fails (say it overheats and the thermal fuse fails shorted) the transformer insulation may break down and couple mains to the output.

There are others on here that have intimate knowledge of PSU design and would be able to explain better than I that the subject PSU of this thread is extremely likely to be a safety hazard.

Ian P

[old martParticipant @oldmart]

Without cutting the psu case in half, I couldn't say whether it is a switched mode type, although I did mention not getting a reading with my meter set at 20M, could that be a clue. I thought that 20 meg ohms resistance set on the meter would show something through the primary of a transformer.

[not done it yetParticipant @notdoneityet]

I’ve just checked one of my Swiss socket strips: it says that it is rated at 10A max.

OK, I believe you. But who wants a 10A fuse for a 15-50W soldering iron? That fuse is protecting the spur wiring, nothing else. My one amp fuse in the plug for my soldering iron protects the lead from plug to soldering iron.

I would rather have more safety devices than set fire to the house.

[Andy StopfordParticipant @andystopford50521]

As I understand it, the main, even sole, reason for having a fuse in the plug is to protect the flex in the event of a short circuit in the appliance.

With the high currents possible with a ring main, the circuit has to have a high rated fuse, which might not blow even though a faulty appliance is drawing enough current to set its flex on fire.

Although this kind of fault seems a bit implausible with the sort of things we plug into the mains these days, I suspect it might have been more of an issue when the BS for these was devised, e.g. a radiant bar heater might have a 'partial' short circuit across its coils (amongst its many other house-fire-starting modalities).

[John OlsenParticipant @johnolsen79199]

Generally fuses and circuit breakers really only protect the wiring that is upstream of them. A fuse at the switchboard can protect the wiring against excessive current being drawn by a load plugged in, but it doesn't protect your house from burning down due to a fault in the wiring itself. Such a fault can draw enough current to start a good fire without drawing enough to blow any upstream fuse.

Similarly the fuse in the plug isn't really protecting the load from faults, since if the load is drawing enough to blow the fuse, it is already faulty. It also doesn't completely prevent such a fault from starting a fire, since even 1 Amp at 240 Volts is enough to get quite a good fire going.

Different countries have different rules for this sort of thing, and they all justify them as being safer than anyone else's methods. They can't all be right. For instance, the Americans claim their lower Voltage is safer, but that requires twice the current for any given device, which is more likely to cause problems with bad joints. So maybe less electrocutions and more fires? I doubt if anyone is collecting detailed statistics to actually prove it either way.

John

[OldironParticipant @oldiron]

Posted by DrDave on 30/03/2020 18:01:29:

I have never understood the British love of fused plugs: most of the world seems to be happy with unfused plugs. None of the electrical equipment that I bought when I lived in Switzerland has a fused plug, for example.

Other than the regulatory requirement here (and after all it does sound like a good idea), can anyone explain why Britain and the colonies have this different plug philosophy?

AFAIK The UK uses a ring main circuit where all the sockets in the ring are protected by one fuse/breaker. Therefore all plugs attached to appliances need to have a separate fuse to protect items of differing current draw. Much of the rest of the world use a radial system where each socket is protected by its own fuse/breaker at the distribution board.

regards

[old martParticipant @oldmart]

The common circuit breaker rating for a ring main is 32A and a radial is 16A in the UK. If a radial ends in a double socket, it should have a fuseholder supplying the socket with a 13A fuse in it. This is to prevent overloading the radial.

Regarding the rest of the world system, the circuit breaker/fuse protecting the radial is rated for the largest load allowed, fine for an electric fire, but not much cop for a phone charger.

[DMBParticipant @dmb]

In my workshop, all the power sockets are on a ring circuit from a main switch in the shed. Lighting is from the same main switch box but arranged as a radial down either side of shed. All individual items are always at least switched off at the plug, but the Newton Tesla vfd for the Myford is unplugged until wanted to use, so as to be sure of protecting expensive kit. Special close up led lighting on mill supplied by dodgy looking wallwart transformer plug also only plugged in when needed to prevent fire. Only heating left switched on, in use 24/7.

If I go out or going to bed, most items in the house switched off at the plug, not left on standby like I understand people do with their TV. Of course, all but the freezer and fridge get the plugs pulled during thunderstorms, including workshop power. Reduces number of burnt out appliances if struck. Too bad about the hardwireds, Insurance claim for them.

What does it matter if UK does house wiring differently to the rest of the world? It works and seems safe enough. Next time you go to France, take a look at their grid pylons, totally diff. design to ours but they work. Just more than one way of skinning the moggy.

[Paul LousickParticipant @paullousick59116]

We have never had fused plugs in Australia. Originally only a main fuse at the switchboard to protect each circuit. 10A fuse for the lighting circuit and 15A for power circuits. Now it is mandatory to fit earth leakage circuit breakers which will trip if an overload or if there is a short to earth is detected.

Paul

Edited By Paul Lousick on 30/03/2020 22:59:01

[Don CoxParticipant @doncox80133]

My father was a sparky from the age of 14 and was born in 1909, he used to tell of being sent from his home town Bath to London when in his early 20s and of being told by his boss to pick up the IEE (or equivalent then) wiring regs which were at that time about 15 pages long. He stayed in the industry all of his working life. Many years later, as part of my transition from 33 years with BT as a telephone "engineer" I took and passed the IEE 16th editions wiring qualification, my (paperback) book was about 3/4" thick.
My understanding of domestic voltage choice, now 230v, was that it was the highest which was still reasonably safe to have in that environment. The continentals double pole switch all of their devices because they can't rely on maintaining live/neutral polarity , nowadays all socket and lighting circuits are RCD protected and virtually all appliances are double insulated with very few metal bodied , class one, devices about. All of my domestic circuits are RCBO protected.

[ChrisHParticipant @chrish]

Coming in on this thread very late in the day and I admit I have not read all the posts, but, I see several posts say if a plug (in the UK) does not have an intergral fuse it's illegal, and that the kit needs a CE mark, which I understand all electrical equipment certified for use within the European Union must have. Please correct me if I'm wrong.

My question is, if we have to have a fuse in a plug in the UK, why are there no fuses in any plugs on French electrical equipment? (Or is this another one of the one rule for us and another for them and to hell with standardisation across the EU?) And following on from there, why are all domestic UK electrical power circuits ring mains and in France they are radial. And why in the UK do we use flat twin and earth cable with the earth wire a smaller diameter than the others, but in France earth, live and neutral wires must all be of the same diameter (UK flat twin and earth is not allowed to be used in France)?

I am not trying to make any points here at all, I really just do not understand these things and would be grateful if anyone could explain! I thought the whole point of the EU (when we were in it) was that all had to follow the same rules, when evidently there are differences and we didn't.

Chris.

Ho Humm!

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