RCDs in series

[Doctor Drivel]

Installing a whole re-wire: ring circuit vs a German/Dutch radial circuit. The ring will be much cheaper. The prime reason it is used.

The Dutch safety record is half of ours.

[Doctor Drivel]

The US plugs are used in North and South America and other countries too. Also because of the large population in the US more people use their systems than ours. Those who adopted the British systems tend to be ex empire countries, choosing a mother country system rather one on technical merits.

[Doctor Drivel]

Yep.

Yep.

Not the fault of the radial system.

High trip current? 16A MCBs or RCBOs on 8 sockets is not high. If a simple fuse fails in a plug the protection is a 32A MCB (or fuse)

There are unprotected openings now in some sockets I have seen. And the cheap contractors will use them. I have seen fuseless plug too (I suspect illegal imports, not sure).

There is a standard to where live should be connected, but most don't stick to it.

"improved safety of the ring" Where? A radial circuit with RCBOs, tripping on neutral and live, on each circuit is much safer. The UK ring system trips on 32A and only the live. Most new Continental systems have RCBOs.

Fires in the UK are caused by the same problem. Most homes I see have trailing extension leads, especially around computers, TVs, etc. Most homes need banks of 6 wall of sockets> Do you see them?

There would be. A 16A RCBO at the CU, rather than a 32A RCBO. 1363 relies on old hat fuses in plug tops.

If I did a re-wire, it would have radials and RCBOs. RCBOs are cheap in the likes of France and buying a CU complete with them (Legrand for e.g.), they are "much" cheaper than the UK, where RCBOs are extortionate.

[Andrew Gabriel]

The beauty of a simple fuse is that it doesn't fail. If it blows, you know exactly which appliance caused it to do so, as it's tied to the appliance. When a continental circuit blows, you have no idea which appliance did it (unless one of them is also emitting smoke), nor if it's a faulty appliance or if you just overloaded the circuit (which is also all too easy to do) or if it's a faulty circuit. UK system handles that much better, which is not surprising as it's a newer design which was intended to avoid that problem.

No there aren't.

Considering the two most common continental sockets, the Shucko has a completely reversible plug, so wiring up the socket in any particular way would be pointless. The French/Belgium plug isn't reversible in the same way, but you'll find each socket on a double socket or 2-way adaptor is hard-wired the opposite way around, so there's no standard there either. Furthermore, some areas which use these connectors don't have a live and neutral, as neither conductor is guaranteed to be near earth potential, which again makes any differentiation of which pole is live completely meaningless. So your statement is completely wrong.

You have to switch both poles when you don't have a live and neutral.

No they don't.

Many of the radial schemes limit the number of sockets you are permitted on one circuit. This makes it much more complicated to add extra sockets, as you'll usually find you need a new circuit, and often a new CU. Hence the very widespread use of trailing socket blocks and multi-way adaptors on the continent.

BS1363 limits the effects of a fault to the faulty appliance.

I've never once seen an RCBO in France, and Legrand don't even appear to sell them in France (although they do in the UK). The french do have whole-house RCD's though, and as they are part of the suppliers works, you can't remove them. Although they are rated 500mA, an earth fault whilst you are on holiday will result in thawed freezer and dead tropical fish, etc.

[John Rumm]

When you have a couple of non RCD protected circuits for fixed appliances and vulnerable equipment, that sounds quite reasonable. Especially as with a 16A design load you will need one circuit per major kitchen appliance. You end up with lots of redundant copper with a slight reduction in performance of the circuit under fault conditions.

According only to you it seems. Rings circuits are cost effective and good design.

Explain?

Split load?

Yet you seem incapable of explaining it... odd really.

You fitted the wrong fuse no doubt.

Use of whole house RCDs is deprecated. Use of RCDs on lighting circuits is contra to regulations, user of RCD protection on circuits offering little direct contact possibility is also not required.

Blowing lamps will not take out a RCD unless it is already close to its leakage budget due to too many or inappropriate appliances being fed from it. Something I guess you are about recommend....

Superior by having lower quality accessories, built with less stringent quality control. A myriad of ways of incorrectly mating a plug with a socket, and a higher accident rate. All while consuming a significant amount of extra copper.

Could you elaborate on your definition of "superior"?

Not really:

1) The RCDs primary purpose is to protect the user from direct contact shocks[1]. The direct contact risk from a dishwasher or washing machine or immersion heater is pretty much nil. 2) Correct earthing (and the higher integrity of ring circuit earthing helps here) gives adequate protection against indirect contact shocks. 3) Appliances such as those mentioned can have high leakage do to their mineral insulated heater elements. This can result in sensitisation of a RCD, which in turn can lead to nuisance tripping problems. [1] TT Systems excepted

[John Rumm]

The reasons its used:

More flexibility Better fault tolerance, and less fire risk Easier to install Less materials

7.2kW load capacity Over current and fault current protection accurately matching the needs of the connected appliances and the circuit. Better discrimination on appliance overcurrent.

Oh, and you are right, it is cheaper as well. A win win win win win win win win win situation as you would say.

Recorded using what criteria?

What about the German and French that use similar systems to the Dutch with dramatically poorer results?

[John Rumm]

It is partly. The cost of providing adequate socket outlets to match modern patterns of usage using this method is too high. Hence installers tend not to.

Tricky to draw current through a failed fuse....

Fuseless plugs to BS 1363 three pin form factor are not legal to sell in the UK.

Un-shuttered sockets are also not acceptable for general use.

"553-01-04 Every socket-outlet for household and similar use shall be of the shuttered type and, for an a.c. installation, shall preferably be of a type complying with BS 1363."

(with limited exceptions allowed by 553-01-05)

And you think this is good because?

Which part of "stems largely from secondary effects of the greater number of fixed sockets and fuse protection of the appliance lead". could you not comprehend?

Also consider that of the four most common circuit faults: (vis: high impedance connection in CPC, high impedance connection in Phase/Neutral, open circuit in CPC, open circuit in Phase/Neutral), a ring circuit to modern design will perform better in three out of the four fault scenarios.

Your understanding and nomenclature seems confused.

UK power circuits usually are protected by RCDs. RCDs are double pole devices not single. MCBs do not operate under direct contact shock incidents, and hence there is no advantage to them being double pole. We also keep strict control of circuit polarity and termination.

You seem to be confusing trip hazard with fire hazard.

Fire hazard in continental wiring is perhaps more likely to be caused by the shoddy quality of their plugs and sockets, however the main risks will be similar to ours (unlike when compared to the significantly greater fire risk posed by US style installations and wiring practice)

The internal fusing of BS1363 is one of the reasons for its greater safety and why many countries have adopted it.

There is nothing "old hat" about fuses. There are many situations where they will be preferable to MCBs for example.

You neglect that RCBO protection can be employed on a per circuit basis here as well.

If you are going to rewire anything (especially in dodgy French accessories), please have the courtesy to warn your neighbours in good time so that they can move. Also you will need to keep it all well away from any of your plumbing, because I think you will find that none of the systems are submersible.

[John Rumm]

And at 500mA offer no direct contact protection either.

[Andy Hall]

If it were Easter time, the notion of "Lord forgive them for they know not what they do" would spring to mind......

[Andy Hall]

So you believe that the U.S. system has technical merits?

Have a wander around the electrical section in Home Depot. Even you would be shocked.

They have plastic plumbing as well, but there are pipe slicers in the section where it is sld, I am pleased to report. There is a sign saying "No Hacksaws" in English and Spanish.

[Andy Hall]

Tablets are available on the NHS.

This is true.

This is also true.

No they don't. There are bucket loads of MCBs and large consumer units as one would expect.

[Huge]

On a related topic...

We once looked at a house that belonged to some American ex-pats who had installed a parallel wiring system, using US sockets, with a gigantic 220->110V transformer in the cellar to provide the 110V 'leccy.

Is this legal?

(We didn't buy the house - not because of the wacky electrics, though.)

[Owain]

Well.... the problem is that the US sockets possibly don't comply with the plug and socket regulations for domestic equipment, and almost certainly wouldn't comply with a British Standard, and an installation that uses bits that doesn't comply with BS wouldn't comply with the Wiring Regs.

But actually illegal - not unless it killed someone.

Owain

[Doctor Drivel]

Yes, the rest of the world needs forgiving.

[Andrew Gabriel]

This wouldn't conform to the regs, but that doesn't necessarily make it illegal.

Apparently you can choose to use the regs of any EU country in any other EU country if both have harmonised their regs. UK and France have done this, and a friend's parents wired up their french holiday home to UK regs. Quite surprisingly, EDF who came to wire in the new consumer unit were fully aware of this too, and had no problem with it.

US wiring doesn't come close to meeting any of the EU country standards though. Back in the 1980's, BT applied for type approval of the US socket in the EU. It got a max rating of 50V, 2.5A (or that's what it would have got -- don't know if they persued it).

[Doctor Drivel]

The reason for non-RCD protected circuits is not to trip out the whole house and protect fridges, freezers, etc from thawing. Using RCBOs on "every" circuit you have is a far superior system. Modern radials tend to have RCBOs on them.

No. Anyone with common sense and looks at them. If they are so wonderful why hasn't the whole world adopted them?

Cheapo, and not as good as radial with RCBOs on each circuit.

If you can't figure that out by now.....

No. An RCD on all circuits.

See above.

It can happen.....and did.

Kitchen cabinet lighting is rarely on the 6A lighting circuit.

230V downlights take out the RCD when they fail.

I have seen high quality accessories in Germany, Holland, etc. Get what you pay for, etc, etc.

EU standards.

You are losing it now.

It is? Nil? If only.

[Doctor Drivel]

= cheaper

= less safer.

You are having a laugh now.

= cheaper.

= cheaper.

Unnecessary and no need for such high currents on domestic socket circuits.

You what?

Nonsense.

yes, a win, win for cheapos

Look it up.

A poor culture towards safety. French and German radial using RCBOs on each circuit are superior to our ring circuit socket crap.

[Doctor Drivel]

Matt, you must read what I wrote...if you can of course.

They don't sell hacksaws? Cut them with an axe?

[Huge]

Tell me about it. I've done some odd jobs round my mother's house (in Pennsylvania) and the standard of the electrical installation is terrifying; and it's a new house.

(Incidentally, we had the poles (*) & overhead from our house to the 11kV transformer replaced a couple of months ago, and I was surprised to find out that the overhead is aluminium.)

(* Combination of woodpecker damage and wanting taller ones so the farmer doesn't bring them down with the combine quite so often.)

[Doctor Drivel]

The major problem with the British system is that the correct amp rating of fuse can be omitted, and frequently is, with a larger rating fitted; 13A. Frequenetly a desklanp is on a 13A fuse.

Many do not have the earth pin open the gate, pushing in a knife will open it.

New builds do.

They do sell them in France.

RCBOs vs a whole house RCD is much superior.