New design of mains plug?

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.

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).

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

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

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.

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.

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

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.

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!

I like this type! (Not) 🤣

Johnboy25 - seen similar from Dutch contractors working in the UK trying to get their power tools to go, mostly they used matches not big sticks but............ H&S, eat your heart out!

Just repeated what others said, so deleting it!

Edited By Mark Rand on 31/03/2020 01:02:17

As an outsider, my guess would be that to standardise across the EU would mean such expensive changes and upheaval to entrenched national systems that no nation would agree to it. So they agree to differ instead.

Just a guess though.

Bandersnatch - Yes, but there is no reason why you shouldn't be able to have a fused continental plug as an option. Its the same thing for sockets in France - you can't buy them with a switch, instead you have to have a double gang patrice / box and install a separate switch. Just to make life more interesting on the continent, some plugs have a pair of lugs which engage in slots on the sockets, but French sockets don't have the slots, so Dutch and German plugs won't fit French sockets, but French plugs fit Dutch / German sockets - work that one out.

If every socket/light on a radial system had it's own fuse that would be quite a large consumer unit.

ChrisH,

To answer your question simply (it has been covered in the earlier posts), in the UK the ring main can carry 30A before the cabling starts to warm up seriously. That sort of current, going through a much smaller section of flexible lead would melt the insulation and quite possibly cause a fire, so those flexible leads are protected by a suitable fuse in the plug for that device.

While the radial wiring is protected by the fuse at the distribution board, you would have to ask the french why they do not protect any wiring downstream of the wall socket. Perhaps they only use the same size of conductor in all appliance leads? My 50W soldering iron does not need a heavy supply lead, whereas a 3kW electric fire or an electric cooker requires a much heavier supply after the wall supply switch.

If 30A flexible supply leads were required for UK installations, appliance leads would be much heavier, if they were to be protected by the fuse at the distribution panel.

Two different approaches. Some radial circuits are used in UK domestic wiring, of course.

If my house had to have a separate fuse for every socket radially, I would have to build another house to put them in!

I do not like trailing leads everywhere so every room has more than sufficient double switched sockets so that there is always one to hand.

Workshop is different each machine has its own spur, except the drill.

How on earth did you manage that? I rewired my house in the seventies and put double the number of double sockets I thought I could possibly ever want into every room. There still weren't enough, and some were still in the wrong places!

George B.

Each room has a double either side of each corner and also along the wall as appropriate. Kitchen has 11 for instance (yes not a small kitchen). There are 3 house Ring mains, day rooms ,kitchen and bedrooms. In addition the garage and workshop has a ring main (+ radials), Family and utility has another. These latter rooms are "downstairs" (sloping site). Lighting is similarly split and the security lights are also separate. Dual Dis boards up and down plus incoming master dis board which splits for both and also serves workshop radials. Not a rewire but built in during construction.. At last count there were 160 plus socket locations including the loft which service the aerial amplifiers. OTT maybe but why not?

Edited By KWIL on 31/03/2020 11:47:00

This is a photo of our fuse box for a French 2 bed house. I have to have 3 phase because I have a 950watt under floor heating in the kitchen - REGULATIONS !!!

Besides being 3 phase, there has to be a lightning protection device (which isn't fast enough to protect things like computers and an additional fuse box which services an external electric pump - REGULATIONS.

And not a single ring main or fused plug elsewhere. All circuits are radials with no spurs.

Ps. the mantles are for the oil lamps when we have power cuts.