Continental plugs don't have fuses, so why does UK?

[RF Lighting]

Here we go.

The ring main

You're talking about a ring final circuit. A ring main is used by network distribution.

Learning the correct terminology will add credibility to your argument.

provides a two wire shared load load system with a maximum of 30A

No it doesn't, and a badly loaded ring circuit can allow virtually all the circuit current to travel down one side of the ring.

and two earthing points, The radial system has a limit of 15A

No it doesn't. A radial circuit can be what ever size you want it to be, and in that respect, it's much more flexible than the 30A/32A ring circuit.

and only one earth point,

Lots of things have only "one earth point". Virtually everything else apart from a ring circuit infact.

current wise this may be fine in poor countries which don't have high powered appliances but not in modern societies.

As already stated, radial circuits can deliver less, the same or more power than a ring circuit, so this is simply wrong.

The ring main was designed to provide higher current capability whilst improving safety and load sharing more evenly.

No it wasn't. It was introduced to allow circuits to be wired using less copper due to copper shortages after the war.

Not to mention the increased fire risk of multiple wire junction boxes, it's not the best way of distributing power

You don't need to use junction boxes on radial circuits. The regulations even prohibit them where they are not accessible.

- sticking multiple wires under one screw, they tend to work loose if the rigid wires are moved about.

Just the same as the two wires under one screw in the back of every socket on every ring circuit then?

 

[securespark]

Just the same as the two wires under one screw in the back of every socket on every ring circuit then?

Or three, where a spur is taken off.

 

[Altvamp]

You clearly don't have a clue, your comments are plain stupid,

Are you good at recognising those because of your intimate familiarity with stupid comments?

The ring main provides a two wire shared load load system with a maximum of 30A

Wrong.

The radial system has a limit of 15A

Wrong.

current wise this may be fine in poor countries which don't have high powered appliances but not in modern societies.

Wrong.

The ring main was designed to provide higher current capability whilst improving safety and load sharing more evenly.

Wrong.

Not to mention the increased fire risk of multiple wire junction boxes, it's not the best way of distributing power - sticking multiple wires under one screw, they tend to work loose if the rigid wires are moved about.

I would ask you what on earth junction boxes have to do with anything, but since you don't even know what decade it is I'm not hopeful of any meaningful reply.

Obviously this forum is for trolls and planks, I though it might be.

 

[ban-all-sheds]

I see.

That must mean that you can show the veracity of what you wrote.

Go ahead

 

[streetlighter]

I must admit I use radial socket circuits when I rewire a property now makes life so much easier.
Also there's no worrys about the ring continuity being broken leading to overload or the argument about more current flowing in the shortest leg of the ring.

 

[Taylortwocities]

Obviously this forum is for trolls and planks, I though it might be.

"Plank" hey?

That's pretty rich from someone who has the stupidity to dig up a topic from 2005!!

Did it really take you 6 years to think about your meaningless input?

And, as you seem to be keen on correct terminology, the term "ring main' applies to fluid distribution systems (water typically). Not electrical circuits. You may find that the words "ring final circuit" are more useful in this context.

 

[JohnW2]

Did it really take you 6 years to think about your meaningless input?

8 years (plus a few months), actually ... so a couple more years than you thought to come up with his invaluable input!

Kind Regards, John

 

[Taylortwocities]

Blimey, doesnt time fly!

 

[Porque223]

I guess it's not ad hominem if the comments really are stupid. . .?

 

[securespark]

Obviously this forum is for trolls and planks, I though it might be.

Don't know why you quoted the obvious. It is indeed the forum for trolls and planks.

That's why you posted in an ancient thread with the content that you did.

 

[ericmark]

We are permitted to still use BS 546, BS 196 and BS EN 60309-2 these plugs can have the overload disconnecter at the origin with 2, 5, 15, 16, 30, 32, 63 or 125 amp limits and pre-war we did use this system.

It does however mean huge fuse boxes/consumer units with many circuits and to save on copper and to make it so we have just one plug for most uses we went to the BS 1363 (fuses to BS 1362) system this means we don't need to use cables able to stand 16A for items like table lamps or alternatively as we did pre-war use 5A and 15A sockets.

To have a 16A outlet means cable has to be 1.5 mm sq but with the 13A outlet with a 13A fuse 1.25 mm sq dropping down to 0.5 mm sq with a 3A fuse. This allows the use of a far more flexible lead.

The CEE 7/16 Europlug (Type C) plug is rated at 2.5A and has 4 mm pins where the CEE 7/4 (German "Schuko" 16 A/250 V earthed)(Type F) is rated at 16A and has 4 mm pins so the lower current version can be inserted into the higher current socket, it is left to the user to select the correct socket rather than have a fail safe method to stop using wrong socket. Also both types are not polarised so not permitted in the UK. There are versions with 4.8mm pins and also the spread changes and they often lack the insulation on the base of the pins so ones fingers can touch live pins when inserting and removing.

In the UK we do have BS 4573 (UK shaver) which is similar to the CEE 7/16 Europlug (Type C) and the current is limited by the socket transformer and overload protection to 200ma and also is isolated from all other sockets does not require a fuse in the plug.

The disadvantage is the fuse in the plug warms up the plug and so prolonged use with maximum wattage can cause them to over heat. The plugs are slightly more expensive but the house wiring is less expensive.

Slowly there is a move to radial rather than ring circuits with 20A rather than 32A supplies to each circuit and more circuits as a result. This allows less items to be fed from each RCBO so less tripping due to earth leakage but this is not cheap so many only have two RCD's feeding whole house. Because of the rules with RCD's the standard 4 fuse feeding whole house is no longer an acceptable method and now 6 MCB's and 2 RCD's is about the minimum for a consumer unit. But this is still far less than would be used in same size house using the continental system.

French, Danish, Italian and Swiss do have polarised plugs and sockets but they seem to have allowed the use of the German "Schuko" plug and socket as well which is non polarised but in the UK we will not permit non polarised sockets except for the special bathroom type. However we do allow adaptors so non polarised plugs can be fitted into our polarised sockets. I will guess the polarised sockets are because old equipment often had single pole switching so even when switched off one could get a shock if used with non polarised sockets.

On the continent they used RCD protection well before us and I would guess this resulted in comparable results as to accidents. Now we also have RCD protection on nearly all sockets our accidents reported should drop below the continent however it will take some time before all our properties are upgraded so the change will be slow.

 

[jabuzzard]

The thing is the reason for the introduction of the ring circuit aka the shortage of copper, is as valid today as it was 70 years ago. Put simply long term there is insufficient copper in the world to go around. Consequently any move to radial circuits in a country that already has ring circuits is complete madness from a strategic viewpoint and should be resisted.

On a safety note I would say that unfused plugs and hence unprotected flexes on radial circuits is still a safety hazard. It is hardly better that a cable rated at 3A is pulling 20A rather than 32A. Both situations represent an unacceptable fire hazard.

In general electrical safety in the UK is some of the best in the world. For example compared to the USA deaths by electrocution are 10 times more likely in the USA than the UK, and they use a lower mains voltage to boot, and have that radial system of wiring.

 

[rjm2k]

I read that polarity is important due to some types of lamp holder which use the outer part as a conductor - with it being earthed it's safer forcing that to be neutral than having the live on the outside. The appliance itself doesn't know the difference as it's AC anyway.

How does safety of such lamps match up in places which don't force polarity to be one way or another vs those that do?

 

[jabuzzard]

I read that polarity is important due to some types of lamp holder which use the outer part as a conductor - with it being earthed it's safer forcing that to be neutral than having the live on the outside. The appliance itself doesn't know the difference as it's AC anyway.

How does safety of such lamps match up in places which don't force polarity to be one way or another vs those that do?

Edison screw lamp fittings are inherently not as safe as bayonet ones. On an Edison screw it is important that the outside screw bit is connected to neutral for safety purposes. If you have unpolarized plugs like Schuko or the USA ones then you cannot guarantee that. With a bayonet light fitting you can wire it up either way around and it is not important. Even better there is a potential with a bayonet fitting for the twisting action of removing the bulb to disconnect the mains from the two pins (see MK's Shockguard light pendant) for even greater safety.

Like I said previously the UK has probably the safest electrical system in the world.

 

[mfarrow]

Neither the bayonet nor the edison screw is very safe in my opinion, yet I still read people on here complaining about how unsafe Wylex standard equipment is.

I can see a future for ring final circuits but not necessarily how we use it at present. 32A is a lot of current for a modern domestic situation outside of a kitchen, and replacing these with a 20A breaker would lift the restrictions associated with the BS1363 assessory requirement, and ensure that whatever load you put on it, in whatever part of the ring, it would be compliant and safe.